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PW06-169 - Original - Signal Electric - Settlement Agreement - 11/17/2005
KEATING,BUCKLIN&MCCORMACK,INC.,P.S. JOHN L McCORMACK ATTORNEYS AT LAW STEPHANIE E CROLL MARK R BUCKLIN RICHAftO B JOLLEY RANDAL W EBBERSON 800 FIFTH AVENUE,SUITE 4141 BRENDAL BANNON STEVEN L THORSRUD KELLY M WILEY MICHAELC WALTER SEATTLE,WASHINGTON 9B104-3175 MARYANN MCCONAUGHY ANDREW G COOLEY PHONE (206)623-8861 SHANNON M RAGONESI STEWARTA ESTES KIMBERLYJ WALDBAUM DEBORAH D BROOKINGS FAX (206)223-9423 JEREMY W CULUMBER CHLOETHIELW De$AEESE E-MAIL kbm@kbmIawyers corn JAYNE L.FREEMAN ROBERT C KEATING(isle-2 mp December 7, 2005 ATTORNEY/CLIENT PRIVILEGED INFORMATION NOT FOR PUBLIC DISCLOSURE Via Email Only Tammy White Legal Department City of Kent 220 Fourth Avenue South Kent,WA 98032 RE: Kent adv Signal Electric Dear Tammy: Enclosed is the City's copy of the Settlement Agreement between the City of Kent and Signal Electric, fully executed by representatives for each party. Signal Electric's attorney, Billy Plauche, advises that he will file a Stipulation and Order dismissing Signal Electnc's lawsuit this week. I will forward a copy of the final Order of dismissal to you upon receipt. Sincerely, Stephanie E. Croll SEC/cj l Enclosure cc (w/o encl.): Thomas Brubaker Chris Hills Reed Hardesty(via e-mail w/encl.) K\SEClwcia04163�1-1 2 0705-white doc ®th Anniversary B �� 2025 First Avenue,Suite3140 500 n Seattle,WA 98121-3149 9540 G o r o� 1 LLP 206-626-0675 206-626-0675 Fax Attorneys at Law www buckgordon com MEMORANDUM OF TRANSMITTAL TO: Ms. Stephanie E. Croll Keating, Bucklin & McCormack, Inc., P.S. 800 Fifth Avenue, Suite 4141 Seattle, WA 98104-3175 DATE: December 2, 2005 RE: Signal Electric v. City of Kent We transmit the following: Copy of signed Settlement Agreement A conformed copy of the Stipulation and Order for Dismissal will be forthcoming ❑ For your information. ❑ For your signature and return to this office, ❑ Please file original, acknowledge receipt on copy, and return acknowledged copy in enclosed self-addressed envelope. Q Other: For your records TRANSMITTED BY: Brent Carson BC.TAD Enclosure SETTLEMENT AGREEMENT THIS SETTLEMENT AGREEMENT is made and entered into this_day of , 2005 ("Effective Date")by and between the City of Kent,Washington,a Washington municipal corporation(the"City") and Signal Electric,Inc., a Washington corporation("Signal") (the City and Signal are collectively referred to as the"Parties"): WHEREAS, Signal is the owner of real property located at 1001 3`1 Avenue South,Kent, Washington(the"Property"),consisting of three lots numbered 1, 2 and 3, which are legally described in Exhibit 1 attached hereto; and WHEREAS, on September 20, 1999, as part of a proposal to develop Lot 3 of the Property,Signal's predecessors in interest and the City executed a sensitive area easement, Auditor's No. 19991004001810, applicable to wetlands located on Lots 1 and 2 of the Property (the"Easement"). The location and extent of wetlands covered by the Easement was based on a wetland delineation prepared in 1995 ("the 1996 Delineation") a copy of which is attached hereto as Exhibit 2; and WHEREAS, Signal prepared a Hydrology and Wetland Assessment report for Lots 1 and 2 of the Property,dated June 26, 2003 ("the 2003 Delineation"), a copy of which is attached hereto as Exhibit 3. Signal contends that the 2003 Delineation showed an absence of wetlands on Lots I and 2 of the Property. The City disagreed with this contention,which is part of the basis for the dispute between the Parties; and WHEREAS, a dispute arose between the Parties regarding the possible impacts to Lots 1 &2 that might have resulted from subsequent storm drainage improvements the City made pursuant to Local Improvement District No 352(LID 352); WHEREAS, Signal sued the City over this dispute in King County Superior Court,Cause No. 04-2-34032-2KNT (the"Lawsuit"); and WHEREAS,the Parties enter into this Agreement to resolve the issues set forth in the Lawsuit in an amicable manner. NOW THEREFORE, IN CONSIDERATION of the mutual promises, covenants and agreements contained herein, City and Signal agree as follows: SUYP31CNALELHG7RIC4¢mFNprhWMa1.SeTEN6N7AGReeI9Jf,DpC 1 I. PROHIBITED MODIFICATIONS TO LID 352. A. Existing LID Improvements. Exhibit 4 hereto is a set of as-built drawings that show the LID 352 Improvements as they exist on the effective date of this Agreement. The Parties agree that, for purposes of this Agreement,Exhibit 4 establishes the character, scope, size, and design of the LID 352 Improvements as of the effective date of this Agreement. B. Scope of Prohibited Modifications. The City agrees to make no Prohibited Modifications, as defined in this section of the Agreement,to the LID Improvements. "Prohibited Modifications"are defined as changes, improvements, extensions, corrections, or revisions to the LID 352 Improvements that result in water migrating to Lots 1 and 2 of the Property that does not flow to those lots as of the effective date of this Agreement, or that affect or impede the present drainage of surface or ground water off of Lots 1 and 2. C. Repair and Maintenance. Prohibited Modifications do not include regular and/or emergency repair or maintenance of the LID Improvements, as needed,to ensure the public's health,safety, and welfare. Prohibited Modifications do not include any activity that restores the character, scope, size,and design of the LID Improvements to their condition as they exist as of the effective date of this Agreement. D. Disputes Related to Prohibited Modifications. The Parties agree to the following process to resolve any dispute or claim arising under this Agreement as to whether an activity is a Prohibited Modification. Nothing in this Section shall restrict or limit the ability of any Party to obtain injunctive relief in any court of competent jurisdiction if such injunctive relief is necessary to avoid imminent or irreparable harm to any of the Parties,wluch might occur prior to or during the pendency of the dispute resolution process described herein. 1. Informal Resolution. In the event of a dispute or claim as to whether an activity constitutes a Prohibited Modification under this Agreement,the complaining Party shall provide a written Notice of Dispute to the other Party. The Notice of Dispute shall describe the nature of the dispute or claim. The Parties shall meet within ten(10) days of the receipt of a Notice of Dispute in an effort to resolve the dispute informally("Informal Resolution") 2. Mediation. If any Party believes that the Parties are unable to resolve,through Informal Resolution, a dispute or claim as to whether an activity constitutes a Prohibited Modification under this YAwMGNAL ELEMIC\$unEmewr\nKnLSEmammAommDrr.om Agreement,that Party may give written Notice of a Demand for Mediation("Notice of Mediation")to the other Party. Within five(5)days of receipt of a Notice of Mediation, the Parties shall mutually select a mediator. A meeting with the mediator shall be held within fourteen(14)days of the mediator's selection,on a date and at a time selected by the mediator after consulting the Parties. The mediator shall work with the Parties to produce a suitable compronuse. The mediator shall establish the format of the Mediation meeting. In the event Mediation is invoked under these provisions, each Party to the Mediation shall be responsible for its own costs and fees. The Parties shall evenly divide the costs and expenses billed by the mediator. E. Enforcement of Prohibited Modification Restriction. The Parties agree that in the event of a breach of this Section of this Agreement(Section I,Prohibited Modifications to LID 352), the aggrieved Party shall be entitled to seek injunctive relief as well as damages for any such breach. H. WETLANDS DETERMINATION. The parties agree that after January 1,2006, Signal may prepare a wetland detennmation/boundary delineation for the Property and submit it to the City for review. The delineation must be done during the growing season of March I through May 1. The parties agree to use the official precipitation data from Kent weather station 454169. In the event that there is a delay in NOAA posting the"official"precipitation data on its website, then the parties agree,in the interim,to use the unofficial data as reported directly from Kent weather station 454169. The Kent weather station is located at Fire Station 76; whose address is 20676—72"d Avenue South,Kent, Washington If interim data is used,then official data shall be substituted as soon as it is posted on the website. The City's final decision regarding precipitation data shall be based on the official data. In the event official data is not available from Kent weather station 454169,the City's final decision regarding precipitation shall be based on data from the Seattle Tacoma International Airport weather station(COOP ID 457473; WBAN ID 24233). The parties agree that review of the precipitation data used by Signal Electric to support its determination/boundary delineation will be conducted pursuant to the report attached hereto as Exhibit 5,entitled"Accessing and Using Meteorological Data to Evaluate Wetland Hydrology" (the"Wetland Hydrology Report"). The parties further agree to use the Combined method set forth in the Wetland Hydrology Report to: (i)evaluate the hydrologic data collected by Signal Electric from the Property, and (ii)to determine whether precipitation has been within the range of normal for the 12 months preceding the collection of the same data. If data is within or above the range of normal,the applicant may then utilize the hydrologic groundwater data they are concurrently collecting on site to support the wetland delineation determination. Y-\WMGWAL Fa.EcMCWMTcMW%FnMWrmrsmEWAGRWM err we 3 Signal's wetland determination/boundary delineation shall include copies of its hydrologist's supporting data sheets. The determination/delineation shall be reviewed by the City in accordance with the applicable provisions of the City's Code, including Kent City Code Ch, 11.06. Signal shall provide the City with written notice that it is collecting data for the determination/delineation at least two business days prior to that data collection and shall allow the City to observe the data collection process if the City so requests The wetland determination/boundary delineation shall be forwarded to the City within ten(10)days of its completion. Not more than 45 days after receipt of Signal Electric's wetland determination/boundary delineation,the City shall complete its review of(1) the determination/delineation and(2) the precipitation data,which will be done using the Combined method set forth in the attached Wetland Hydrology Report. During its review,the City may verify the accuracy of, and may render boundary adjustments to,the wetland boundary delineation. Upon conclusion of its review,the City shall issue its Determination("the Determination"). The Parties acknowledge that the Determination may show that the wetland areas on the Property have either(1)not changed in size since the 1995 Delineation, (2)increased in size since the 1995 Delineation, (3) decreased in size since the 1995 Delineation, or(4)no longer exist. Signal shall have the right to appeal the Determination pursuant to the procedures set forth in Kent City Code section 11.06.080.C. If not appealed,then this Determination will become the Applicable Wetland Determination of the City for Lots 1 &2 of Signal Electric's Property. If the Determination is appealed,then the Applicable Wetland Determination shall be the final decision of the administrative or judicial body from which no appeal is taken by either Party. M. AMENDMENTS TO EASEMENT. If the Applicable Wetland Determination shows that the wetland areas on Lots I and 2 have either increased or decreased in size,the City Attorney shall recommend to the City Council that the City Council amend the legal description of the wetlands on Lots 1 and 2 of the Property, as stated in the Easement, to conform to the applicable Wetland Determination. Nothing in this agreement shall be deemed a waiver of Signal's right to legally challenge the City Council's final determination in regard to amending the legal description of the Easement. IV. TERMINATION OF EASEMENT. If the Applicable Wetland Determination concludes that no wetlands remain on Lots I and 2 of the Property,then the City shall file a termination of the Easement within 60 days. V. PERMIT REVIEW. YAWPMNALELI[CnUC%,SEr won,\N"N.SEln PNTAomEMFMWC 4 The City shall review any future permit application to develop Lots 1 and 2 of the Property(the"Development Application") consistent with applicable City regulations,including the Easement (if the Easement has not been terminated as set forth in Section III,above). Signal retains all rights to appeal any decision of the City related to the Development Application pursuant to the applicable provisions of the Kent Municipal Code, VI. DISNUSSAL OF THE LAWSUIT, Within five(5)business days of the execution of this Settlement Agreement by both Parties, Signal agrees to dismiss the Lawsuit with prejudice and without cost to either Party. VII. GENERAL PROVISIONS. A. Entire Agreement. This instrument and the attached exhibits comprise the entire agreement between the Parties with respect to the subject matter hereof and shall not be modified or amended in any way except in a writing signed by duly authorized representatives of the respective Parties or their successors in interest or assigns. B Enforcement. The Parties retain all rights, legal and equitable,to enforce this Agreement provided to them under applicable Iaw. C. Notice. Any notice or other communication of any sort required or permitted to be given hereunder shall be in writing and shall be deemed sufficiently given if personally delivered or three days after being mailed by certified mail as follows: To City: Mr.Thomas C. Brubaker Or Present City Attorney for the City of Kent City Attorney 220 Fourth Avenue S. Kent,WA 98032-5895 To Signal: Mr.Jerry Vosberg Vice President of Signal Electric P.O. Box 6209 Kent,WA 98064-6209 And to: Mr.Brent Carson Attorney for Signal Electric Buck&Gordon LLP 2025 Fist Avenue,Suite 500 Seattle,WA 98121-3140 D. Governing Law. This Settlement Agreement shall be governed by and construed in accordance with the laws of the State of Washington. Venue for any action arising out of this Settlement Agreement shall be in King County,Washington I YAWFOGNAL ELEMIMMIEMMTNS MLW"tEMWA0R1MWTAOC 5 E. Headings. The headings and subheadings contained in this instrument are solely for the convenience of the Parties and are not to be used in construing this Settlement Agreement. F. Authori . The persons executing this Settlement Agreement on behalf of the respective Parties hereby represent and warrant that they are authorized to enter into this Settlement Agreement on the terms and conditions herein stated. G. Fair Interpretation. The Parties hereby represent and warrant that they had the opportunity to independently consult with legal counsel regarding this Settlement Agreement, that they have done so, and that they have executed this Settlement Agreement voluntarily and without fraud, duress or undue influence. In the event it should be determined that any provision of this Settlement Agreement is uncertain or ambiguous, the language in all parts of this Settlement Agreement shall be deemed drafted by both Parties, in all cases, construed as a whole according to its fair meaning and not strictly construed for or against either Party. H. Severability. Should any provision of this Settlement Agreement be deemed invalid or unenforceable pursuant to a final determination of any arbitrator or court of competent jurisdiction, the Parties agree that the remaining provisions of this Settlement Agreement shall remain in full force and effect. I. Counterparts. This Settlement Agreement may be executed in counterparts, all of which shall be deemed an original as if signed by all Parties. J. Binding Effect. This Settlement Agreement shall be binding upon the respective successors and assigns of the Parties hereto and shall inure to the benefit of and be enforceable by the parties hereto and their respective successors and assigns. IN WITNESS WHEREOF, the Parties have caused this Settlement Agreement to be executed the day and year first above written. CITY OF KENT,WASHINGTON, SIGNAL ELECTRIC, INC., a Washington municipal co ration a Washington corporation By By Jerry Vosberg Tit : Mayor Title: Vice President Yi\WPWGNAL eEcrmcNSCMW®.rwr SMLmwrAcm� vw 6 E. Headines. The headings and subheadings contained in this instrument are solely for the convenience of the Parties and are not to be used in construing this Settlement Agreement. F. Authori The persons executing this Settlement Agreement on behalf of the respective Parties hereby represent and warrant that they are authorized to enter into this Settlement Agreement on the terms and conditions herein stated. G. Fair Interpretation. The Parties hereby represent and warrant that they had the opportunity to independently consult with legal counsel regarding this Settlement Agreement, that they have done so, and that they have executed tlus Settlement Agreement voluntarily and without fraud, duress or undue influence. In the event it should be determined that any provision of this Settlement Agreement is uncertain or ambiguous,the language in all parts of this Settlement Agreement shall be deemed drafted by both Parties,in all cases,construed as a whole according to its fair meaning and not strictly construed for or against either Party. H. Severability. Should any provision of this Settlement Agreement be deemed invalid or unenforceable pursuant to a final determination of any arbitrator or court of competent jurisdiction, the Parties agree that the remaining provisions of this Settlement Agreement shall remain in full force and effect. I. Counterparts. This Settlement Agreement may be executed in counterparts,all of which shall be deemed an original as if signed by all Parties. J. Binding Effect. This Settlement Agreement shall be binding upon the respective successors and assigns of the Parties hereto and shall inure to the benefit of and be enforceable by the parties hereto and their respective successors and assigns. IN WITNESS WHEREOF,the Parties have caused this Settlement Agreement to be executed the day and year first above written. CITY OF KENT,WASHINGTON, SIGNAL ELECTRIC, INC., a Washington municipal corporation a Washington corporation By: B Jerry Vosbe Title: Mayor itle: Vice P sident YOI MONAL ELBMIctsniteME \A?l&SMYEMENMAopmmERT Doc 6 STATE OF ) ss. COUNTY OF ) I certify that I know or have satisfactory evidence that Jerry Vosberg is the person who appeared before me, and said person acknowledged that he signed this instrument, on oath stated that he was authorized to execute the instrument and acknowledged it as the Vice-President of Signal Electric,Inc. to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. Dated: , 2005. (Signature) Print Name My appointment expires STATE Oj — ss. COUNTY O ) I certify that I know or have satisfactory evidence thQ the person who appeared before me, and said person acknowledged that he ' ed this instrument, on oath stated that he was authorized to execute the instrument and acknowledged it as the Mayor of the City of Kent to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. Dated: 2005. D. a (Igpature) Print Name LIG My appointment expires/.;k -/q_pg �4y�f WAS*'*. TAW AIGNAL ELECMTCVETMM4EWrjt SErrL MTAGRUMWT me 7 STATE OF We, i n ) ss. COUNTY OF -K—C& - ) I certify that I know or have satisfactory evidence that Jerry Vosberg is the person who appeared before me, and said person acknowledged that he signed this instrument,on oath stated that he was authorized to execute the instrument and acknowledged it as the Vice-President of Signal Electric,Inc. to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. Dated: L ,2005. (Signaturey,, (= Print Name My appointment expires N g c 4 STATE OF ) ss. COUNTY OF ) I certify that I know or have satisfactory evidence that is the person who appeared before me, and said person acknowledged that he signed this instrument,on oath stated that he was authorized to execute the instrument and acknowledged it as the Mayor of the City of Kent to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. Dated: ,2005. (Signature) Print Name My appointment expires Y-%WFWGNALMECTRICNSMTLLmorAR)4M.sffmAm NfAGRamo fnm 7 ` SCHEDULE OF EXHIBITS Exhibit 1: Legal Description of Signal Electric properties Exlnbit 2: 1996 Delineation Exhibit 3: 2003 Dehneation Exhibit 4: As built drawings of LID 352 Exhibit 5: Report entitled"Accessing and Using Meteorological Data to Evaluate Wetland Hydrology" (the"Wetland Hydrology Report") Yi\WP\4IGNAL ELF�R�CISflTIEFSFN�\F1NALg1'r1FMENfA�1E�lo+i.oOC 8 y IL , EXHIBIT I 1 x2bibit „all Lots 1, 2 and 3, as described and delineated on City of Kent Short Plat No. SPC-80-15 called CCI Tracts, recorded under King County Recording No. 8011190809, being a portion of the Samuel W. Russell Donation Land Claim No. 41, in the North halt of Section 25, Township 22 North, Range 4 East, W.N., in King County, Washington. i a 153—MB 272ND/277TH CORRIDOR Page 16 of 19 1 L4391804801534 WK 216 CF m 10 0 y 11991�11 1:1. !a:irIC w TIT•G 26 9P 'IA7'a!DgiM�JPAdc»]wn�rarwr.�r-•ww a.wn.......•...-.—..�..�.._•---..__. ' EXHIBIT 2 VINCENT MENNELLA PROPERTY FINAL WETLAND MITIGATION PLAN of on P,gyneedn9 C E `7 1� S/�l�. �r� Off '�d✓ Prepared For Martin Smith, Inc. � � Seattle, Washington 1 Prepared sy. TALASAEA CONSULTANTS Woodinville, Washington December 23, 1996 I I l l VINCENT MENNELLA PROPERTY FINAL WETLAND MITIGATION PLAN 1 _ 1 - 1 1 Prepared for Mr. Doug Holms Martin Smith Inc. 1 1109 1st Avenue, Suite 500 J Seattle, Washington 98101 JPrepared by. Talasaea Consultants 15020 Bear Creek Rd. N.E. Woodinville, Washington 98072 December 23, 1996 TABLE OF CONTENTS Page 1.0 PURPOSE 1 I 2.0 EXECUTIVE SUMMARY 1 3.0 GOAL AND OBJECTIVES 2 4.0 PROPOSED MITIGATION 2 I 4.1 Existing Site Description 2 4.2 Hydrological Support and Grading 2 4.3 Soils Assessmeni 3 4.4 Plantings 3 4.5 Habitat Features 3 5.0 CONSTRUCTION MANAGEMENT _ 4 6.0 MONITORING PROGRAM 4 6.1 Vegetation 4 6.2 Wildlife 5 6.3 Water Quality and Hydrology 5 7.0 SUCCESS CRITERIA 5 8.0 MAINTENANCE(M)AND CONTINGENCY(C) 6 4.0 PERFORMANCE BOND 7 f 10.0 AS-BUILT PLAN 7 I FIGURES f Figure 1: Location Map I APPENDICES 1 Appendix A: Corps of Engineers wetland Boundary Verification Letter DRAWINGS 1 Drawing W1.0: Wetland Mitigation Overview Plan J Drawing W2.0-- Wetland Grading Plan Drawing W2.1: Wetland Grading Specifications &Details 1 Drawing W3.0: Wetland Planting Plan Drawing W3.1: Wetland Planting Specifications&Details 1 J , VINCENT MENNELLA PROPERTY FINAL WETLAND MITIGATION PLAN l (December 23, 1996) ! 1.0 PURPOSE This mitigation plan has been prepared in order to meet the requirements of both the I City of Kent and the Corps of Engineers (Corps Reference 4 95-4-01077)for wetland Impacts. Under the proposed project, 15,719 s.f. (0.36 acres) of wetlands will be filed Since these wetlands have been determined by the Corps to be "adjacent" to the Green River, an Individual Permit is required for the wetland fill. 2.0 EXECUTIVE SUMMARY Development of a 10-acre site for office/warehouse use is proposed by the owner. Approximately 3.8 acres of the site contains wetlands. To minimize impacts to wetlands, the proposed development would occur only on the soi;them one-half of the property-which contains 0.36 acres of wetland. The subject property is located in the City of Kent,Washington (Section 25, Township 22N, and Range 4E, W.M.). It lies west of South 3rd Avenue and east of South 5th Avenue (Figure 1). A wetland delineation was completed on the site in May of 1995 utilizing the procedures outlined in the Corps of Engineers Wetlands Delineation Manual(1987). See the Wetland Delineation and Study report prepared by Talasaea (dated June 19, 1995)for a complete description of the wetlands delineated on the site. The wetland boundaries were field-verified by the Corps of Engineers during a July 28, 1995 site visit Appendix A contains the Corps'wetland boundary verification letter (dated Sept. 14, 1995)for the site. All of the wetlands on the site are classified as Category 2 wetlands by the City of I Kent. The proposed project requires the filling of Wetland C (12,119 s.f.) and 3,600 s.f. of Wetland B for a total wetland fill of 15,719 s.f. (0.36 acres; see Drawing 1). 'In addition, approximately 0.14 acres of Wetland 8 will be impacted through buffer 1 encroachment of 25 feet. This document outlines the compensatory mitigation efforts which will be undertaken i to replace the functional values lost through the filling of 15,719 s.f of wetlands. As 1 mitigation for this Impact, 23,579 s.f. (0.54 acres) of wetland will be created in the northwest portion of the site. The created wetland will be adjacent to the existing ] wetlands to create a wetland system with higher functional values, and will meet the 1 area replacement requirements outlined in Kent City Code Chapter 11.05 (i.e., 1,5;1 replacement to loss ratio for impacts to Category 2 wetlands). As mitigation for the 0.14 acres.of Wetland B Impacted by buffer encroachment, 0.14 acres of Wetland A will be enhanced. A 50-foot average buffer will be provided adjacent to the.created Jand existing wetlands, as required by the City of Kent for Category 2 wetlands. The i J 1 }IR �N tllL N 7 'c a/ ST J s 36TH ST =.syTCPA '?JAME sr u Y S t+ 2 \_ 6 b �wDy JAHES � � e P1 J MES ^ gd } AMES J PL HET r PtA n+ a AA a- e s ST LN ¢ N TEHP = T E ERUC n yW PC ' M V SMITH <STt SN MEEKER L ST N E ST 23 cs N 2a6TN ST) u CCr DOHE ?t T p N 'a A'Fh? ❑ PD E ^s h PLAN 2 ;E S YES tF N :: 7 E S ATf I Ps "{ t Oilmw co s IPI 0 e f S t t wkr P� 7z sr N ` t Uj I N $ TTl I 4 I I S 637T I I S 262ND ST S 262 �4i� 26 S 266TH S 3 S 259TH ST ,d S 25 ST J LODo ir let N� I Source: The Thomas Guide 1995 i ,• North DESIGN DRAWN FIGURE 1: Location Map IAO (D TALASAEA Mennella Property SCAM RGUWDW:NO. CONSULTANTS Kent,Washington •DkTg ResourcekYnWtoamtnW TIuWn6 IWSISO�M�O,.#AWN.Not tO^/-76" 9wplQ M7•U74Fupa�gY{77rSUVUD wetland buffer adjacent to Wetland B will be reduced to 25-feet, and will be replaced adjacent to the created wetland. 3.0 GOAL AND OBJECTIVES Goal: The primary goal of the mitigation project is to replace the wetland functions and values lost due to the filling of 0.36 acres of wetland. This will be achieved through Integration of a constructed wetland with two existing wetlands to create a larger wetland system having higher functional values. This system will reflect a more diverse plant community, provide greater food chain support for wildlife, enhance water quality, and provide improved stormwater storage. Objectives: In order to accomplish the goal of the mitigation, the following objectives are incorporated into the design of the plan: • create 23,579 s f. (0.54 acres) of new wetland area to replace the 15,719 s.f.of wetland area lost to filling (replacement-to-loss ratio of 1.5:1). increase the wetland and buffer plant species diversity and structure by planting a variety of native herbaceous and woody plant species, create an upland buffer to provide wetland protection and habitat for wildlife (primarily songbirds and small mammals), f . create-diversity in the plant community by grading to varying depths, and incorporate upland peninsulas into the mitigation wetland to maximize edge effect, thus increasing wildlife habitat value. 4.6 PROPOSED wriGATION 4.1 Existing Site Description The mitigation site consists of-an upland area that separates Wetland A from Wetland B. This area has been periodically mowed and is dominated largely by l Himalayan blackberry (Rubus discolor). Topography within the mitigation area is 1 relatively flat, only slightly higher(approx. 16-inches) than the adjacent existing l wetlands. The created wetlands will be constructed adjacent to the existing wetlands to create a larger wetland system with higher functional values. -4.2 Hydrological Support and Grading Following construction, the mitigation wetlands will be hydrologically supported with groundwater and stormwater runoff. An existing ditch In Wetland B currently conveys stormwater that is discharged onto the northeast comer of the site from the surrounding northern and eastern developed areas, to an exit culvert located along the south-central portion of the site. In order to ensure that the mitigation area receives enough water to create the desired hydrological conditions, an adjustabie weir will be placed In the ditch at the southern end of Wetland B (see Drawing 1)., From the weir, a connector ditch would be constructed to allow water to flow westward Into the mitigation wetlands. Th'e weir 2 would be adjustable to provide a mechanism for modifying water levels to achieve optimum functional benefit in the wetland system. Furthermore, rooftop runoff from the development to the south (up to a maximum of 50 GPM) will be routed Into the created wetlands to provide additional hydrologic support. It is our understanding that the City of Kent Is currently proposing to construct•e regional stormwater detention pond Immediately to the north of the site. In order to assure continued hydrologic support to Wetland B, an agreement should be reached with the City that provides for some continued discharge of stormwater into Wetland B following construction of the stormwalerfacility. 4.3 Sails Assessment Soils on the mitigation site and within Wetlands A and B have been mapped as Renton silt loam by the Natural Resources Conservation Service (NRCS). Soil borings taken by Talasaea throughout this area agree with this mapping. Since extended seasonal ponding was observed within both Wetlands A and 9 during the field Investigations, It is anticipated that the mitigation area will not have to be lined to prevent water loss. This assumption Is made because similar soil types are located In both the existing wetlands and the proposed mitigation area. In addition, creation of wetland in the proposed mitigation area will require minimal excavation to achieve the same elevation as the existing wetlands. All soil excavated from the areas proposed for wetland creation will be placed as perimeter berms in the buffer area to the north and south of the created wetland, or will be used elsewhere on the developed portion of the site. 4.4 Plantings The plant species that will be installed in the mitigation area were chosen for a I variety of qualities, including: adaptation to specific water regime, value to wildlife, value as barrier or buffer vegetation, pattern of growth, and aesthetic value. It is anticipated that the wetland area created on the site will be seasonal In nature. As j such, selection of plant species which are both wet-adapted and somewhat drought- tolerant was an important consideration. Native tree, shrub and herbaceous species were chosen to increase both the structural and species diversity of the mitigation and buffer areas, thereby increasing the area's value to wildlife for food and cover: Species of vegetation-that are both . 1 beneficial to wildlife and unfriendly to human*intrusion will be used in areas where J human exclusion is desired. Plant materials will consist of a combination of bare-root specimens,.contalner plants, and cuttings, 4.5 Habitat Features Snags, down logs, and stumps will be incorporated into the mitigation area to provide } ecologically important habitat features. These habitat features will be relocated from } areas on the project site cleared for development. 3 I Snags provide both perching and nesting sites for a variety of native birds. Cavity nesting bird species,'such as tree swallows, violet-green swallows, chickadees, and woodpeckers, would be expected to utilize such features. Down logs provide the slow release of nutrients as the wood decays, and also provide cover for amphibians, small mammals, and other wildlife. Other structures to be Installed for further enhancement of wiidiffe habitat value Include bird nesting boxes and bat roosting boxes. 5.0 CONSTRUCTION MANAGEMENT A pre-construction meeting will be held on-slte to review and discuss all aspects of the mitigation project prior to the occurrence of any construction activity. Prior to commencement of any work in the mitigation area, the limits of grading will be staked, silt fences will be installed at the locations depicted on Drawing 2-o, and significant habitat features and vegetation to be retained or relocated will be.cleady marked in the field. A.biologist will regularly supervise plan implementation during construction to ensure that the objectives and specifications of the mitigation plan are being met Any significant modifications to the design that may occur as a result of unforeseen circumstances will be approved by the Corps of Engineers, Department of Ecology, and the City of Kent prior to their implementation. 1 6.0 MONITORING PROGRAM The monitoring program will be conducted fora period of five years according to the following schedule: { • 30 days after construction completion J • beginning and end of the growing season of the first and second years following construction 1 • annually the third,fourth and fifth years following construction J Monitoring reports will be prepared after each scheduled monitoring event and. J forwarded to the Corps of Engineers, Department of Ecology, and City of Kent. J 6.1 Vegetation Locations will be established within the mitigation area from which photographs will be taken throughout the monitoring.period. These photographs will document general appearance and progress In plant community establishment in the mitigation area. Review of the photos over time will provide an indication of the relative plant growth and general success of the planting plan. Permanent vegetation sampling points will be established at selbcted locations to Incorporate all of the representative plant communities. The same monitoring points Will be re-visited each year,with a record kept of all plant species found. Vegetation will be recorded on the basis of relative percent cover of the dominant species within the vegetative strata. An approximately 10-foot-radius sampling plot will be used for tree and shrub species, while a square-meter sampling plot will be used for herbaceous species. �..! 4 } 1 Vegetation sampling plot and photo-point locations will be shown on an as-built drawing and submitted with the first monitoring report, 6.2 Wildlife Birds, mammals, reptiles, amphibians and invertebrates observed in the wetland and buffer areas (either by direct or indirect means) will be Identified and recorded during scheduled monitoring events, and at any other times observations are made Direct observations include actual sightings, while indirect observations include tracks, scat, nests, song, or other indicative signs. The kinds and locations of the habitat with greatest use by each species will be noted, as will any breeding or nesting activities. 6.3 'Water Quality and hydrology During each monitoring event, an assessment will be made of the water regime within the mitigation area to ensure that proper hydrological conditions exist within Iboth the wetland and Its buffer. General observations will be made of: 1, extent and depth of soil saturation or inundation 2. soil moisture within the root zone, and 3. soil stability within surface conveyance areas and at culverts and the control weir. Water quality w€ll be assessed qualitatively, unless it is*evident there is a serious problem. In such an event, water quality samples will be taken and analyzed in a laboratory for suspected pollutants. Qualitative assessments of water quality may include: i 1. oil sheen or ofher surface films, ( 2. abnormal color or odor of water, 3. stressed or dead vegetation or aquatic fauna, and I4. turbidity. 7.0 SUCCESS CRITERIA Success of plant establishment within the mitigation area will be evaluated on the basis of both percent survival and percent cover of desirable species. Undesirable species include exotic and invasive species such as Scofs broom, Himalayan and 1 evergreen blackberry, reed canarygrass, purple loosestrife, morning glory, Japanese 1 knotweed, and creeping nightshade. For woody planted species, success will be based on at least an 85% survival rate of all planted trees and shrubs, or at least 80% cover of equivalent recolonized native spec€es, by the end of the five-year monitoring period. Success for herbaceous species will be based on an 80% cover j of desirable plant species by the end of the 5-year monitoring period. J . ' S Areal Cover in Planted Emergent Areas- Years After Planting Minimum Percent Cover One year 50% Two years 70% Five years 80% Areal Cover&Percent Survival in Planted Tree and Shrub Areas Years After.Planting Minimum Percent Cover %Survival One year 20% 85% Two years 30% 85% Three years 45% 85% Five years 80% 85% Exotic and Invasive plant species will be maintained at levels below 20%total cover. Removal of these species will occur immediately following the monitoring event in which they surpass the above maximum coverage. Removal will occur by hand whenever possible. 8.0 MAINTENANCE(NL)AND CONTINGENCY(C) Established performance standards for the project will be compared to the monitoring results in order to judge the success of the mitigation project. t Contingency will include many of the items listed below and would be implemented if j these performance standards are not met. Maintenance and remedial action on the site will be implemented immediately upon completion of the monitoring event, (unless otherwise,specifically indicated below). • replace dead plants with the same species or a substitute species that meets 1 the goal and objectives of the mitigation plan (C) j re-plant areas after reason for failure has been identified (e.g., moisture regime, poor plant stock, disease, shade/sun conditions, wildlife damage, 1 etc.) (C) J if necessary, line wetland areas with impermeable material where hydrology is deemed to be insufficient to support the desired wetiand plant community (C) 1 • irrigate following plant Installation as necessary(M) • excavate, as needed, to correct alterations of surface drainage patterns (C) remove/control weedy or exotic invasive plants by manual or chemical means approved by the Corps of Engineers, Department of Ecology, and City of Kent, Use of herbicides or pesticides within the mitigation area would only be implemented if other measures failed or were considered unlikely to be successful, and would require prior agency approval (C & M) • clean-up trash and other debris within the mitigation area on a bi-yearly basis ] clear or repair trash racks and culverts on a bi-yearly basis (M) • selectively prune woody plants to meet the mitigation plan's goal and objectives (e.g., thinning and removal of dead or diseased portions of trees/shrubs)�M) J6 9.0 PERFORMANCE BOND A performance bond or other surety device will be posted with the City of Kent by the property owner to cover costs of total replacement of plantings and monitoring. The 1 bond or assignment may be released in partial amounts at the sole discretion of the City of Kent in proportion to work successfully completed over the first 3 years of the 5-year monitoring period, as the applicant demonstrates performance and corrective measures. If at the end of the third year of monitoring, the standards of success are beingmet then the bond or assignment amount would be reduced to 50%. � g 1 In addition, an agreement will be entered into with the City providing that the mitigation area be maintained as wetland in perpetuity through a conservation easement recorded with the Registrar of Deeds in King County, Washington, 1 10.0 AS-BUILT PLAN Following completion of construction activities, a set of"as-built"plans for the wetland mitigation area will be provided to the Corps of Engineers, City of Kent, and Department of Ecology. The plans will identify and describe any agency-approved changes in grading, planting or other constructed features in relation to the original 1 approved plan. The plans will also show photo-point and vegetation sampling point J locations. 1 ' J . _1 7 APPENDIX A CORPS OF ENGINEERS WETLAND BOUNDARY VERIFICATION LETTER- I l 1 DEPARTMENT OF THE ARMY ; SEATTLE DISTRICT. CORPS OF ENGINEtRSP.O. Box 3755 IG =7IGIIVE® SEATTLE,WASHINGTON 96124.2255 SEP 15 1995 MC�LY TC ATT[NTION e• — — Regulatory Branch SEP 1 G 1995 i Doug Holme Martin smith, Inc. 615 Second Avenue Seattle, Washington 98104 • Reference: 95-4-01077 Martin Smith, Inc. Epear Mr. Holme: This is in response to your request for a written wetland KS+mdary confirmation and s Durisdictional determination for wetlands located on your approximately 10-acre property in Section 25, Township 22N, Range 4E at the city of Kent, Washington. A site visit was conducted by the Corps of Engineers on July 28, 1995. We have determined that the wetlands located on the subject site are considered adjacent to and below the headwaters of the Green River. Therefore, Nationwide Permit 26, as indicated in your application, cannot be used to authorize your proposal to fill approximately 0.36 of an acre of wetlands for construction of a warehouse and associated parking. Any placement of fill into or excavation of wetlands located on the subject site will require an individual Department of the Army permit, unless otherwise I authorized by a nationwide permit, other than Nationwide Permit 26. We concur with the wetland delineation prepared by Talasaea Consultants, dated 19 June 1995. This confirmation of wetland delineation is valid for a i period of 5 years from the date of this letter unless new information warrants Irevision of the delineation before the expiration date. This confirmation of wetl'and boundaries and jurisdictional determination should in no way be construed as a permit for work in wetlands and other waters of the U.S. delineated within the project area. Please inform us within 30 days from the date of this letter, how you wish to proceed- with your proposed project. If we do not hear from you within this time frame, we will 1 cancel your application. • Since a Department of the Army permit is necessary for any work in wetlands or other waters of the U:S-. located within the project area, do not 1 commence construction until a permit has been issued. If you have 'any questions, please contact Ms. Gail Terzi, telephane (206) 764-6903. Sincerely, Robert H. M rtin Chief, Proc si Section Copy Furnished: } Talasaea Consu ltants 1- 15020 Bear Creek Road, N$ Woodinville, WA 98072 1 I l f J i, EXHIBIT 3 Draft i Signal Electric, *Inc. Hydrology and Wetland Assessment Prepared for Signal SleaWa, Ina. P,O. Box 6209 Kent, Washington 98064-0556 I Prepared by: Mara Bou16 Calvin Kelly Dougies Shapiro and Ansnaiates, Ina, 101 Yeater Way, Suite 400 Seattle, Washington 98104 (206) 624-9190 Project Numb®w 1031003 June 26, 2003 / � | � TABLE OF CONTENTS I, INTRODVCTION...........................................,°',,. ,°..` ........... .................. ....1 � 2. PROJECT .~^_..~~~.~~^~~^~~.~~^~~~ .~~.~....^~~ .,r,.~~.^_~ ^,,~,.,~~l � 3. N[ETHO0S............................................. ........... ~°~.~.,~^^^^^^-^^°^^^^"^^^^^~^^^^~~-^^`~^^~~^~^^.4 4^ RE2MTS~..-..-r--..,. ................................................................................................... ....4 � 4.1 Summary of References -.^.°.......,..,,..-.~....~,._...~~.,°,~.,..-.,,.-.-.,....~--.°..,..4 4.2 Wedamu8 Evaluation............................................. .,~..~~.,.,,.^.^^....~.,,.,.^,,^,^,°.,^^^..,5 4,3 Pi,z»metar Monitoring...^^^..°^...._,°..°."~..~- .^°° ~^..~.°.^....._~........°..-.@ 5. DISC71SSION.......',,...........^..,.........~.,.......".................^................................................11 3,1 Wwtlmod Evaluation.................................................................................................11 5.2 PlmzommterMwmtnzing.........................................................,............ ....................l2 6. CONCL0SIOX�...............................................................................................................l3 | 7. IRENCES...............^...................... .~^.~^~..^_ .......................................................... List of Tabl � Table 1: SamplePlot Soil Data 3003 � | Table 2: Sample Plot Vegetation Data 2083.-.-."~-`....°...~,.°~~.~..-~.,..-,..-....~--....,_,6 Table 3' Sample Plot Hydrology Data 2003,.,,°~°°°...,.,^~,~°°..._..,.,,.,.,,~~°,.~-.......^....^`.,.7 � Table4: 1995 Talassea Wetland Delinsati-- Data Summary � Tob� 5: �Plant� -~~~_---~-,~~-,~-~~~..-~.~~.` � Table 6: Iismm#metwr Tuble7: Pi=zwmwter Data 2003 mm�� {�s� �xmmmzd Sorfm� ....-^.-9 Table #: F�zmm��� �� 2003 �� fimom Ground Sun%ce to - ~ ^ ~~ Tablmgt 1995WeD toStanding Wald (iomh=)............................................ ..............................................l8 Table 10. Daily Precipitation Data for the Months of FmbzuuryxMurch, and AUr� � ���� �ochea\..l0 `�able ll: Precipitation Data -.-.-~..,~-.....-,~_....~-,..,-,',.,,,...,,'--.,,.`-,, .-,,......11 Table 12^ K��mxm��um� �f1995 ��pD }��a uod3UO3 Fio��o�tw� Dw�. 13 | ' -= � ~^~~^^^^`^^^^^`°`^^`^�^`~-``^~^-^ List of Fiffurn � ^ ' r�Figure .1' Project Vicinity ~,^-.._,~--,-.-..~.-.,^~~.~,~__~~.~.~.^..~--~.~-.~~..--~~..3 Iigzre2: Wetlithd'Boxmdarims, Sample Plot, Pirmometer, and Well Locations.................................3 � � | � � � 1. INTRODUCTION Shapiro and Associates, Inc. (SHAPIRO) assessed the hydrology and wetland status of the approximately 5-acre SigtW Electric Inc, (Client) property in the City of Kent (City), King County,Washington(Figure 1).The site is in Township 22 North,Range 4 East, Section 25, It is undeveloped, as is the parcel to the nort8. A 5-acre developed parcel that also is owned by the Client abuts the southern border. Fifth Avenue South forms the western border and 3xd Avenue South forms the eastern bonder, The lead west of 5tb Avenue South and east of 3rd Avenue South is zoned industrial or commemcial(Figure 2). SHAPIRO scientists visited the site weakly during March and April 2003 to (1) perform a wetland recomraissauce; (2) install pimometers, (3) monitor the piezopmeteri, and (4) assess wetland and hydrology conditions based on the information collected in-items 1 and 3. This report describes the methods used in the field investigation and SWIRO`s :findings. 2. PROJECT BACKGROUND A wetland delineation report was completed fu May 1995 identifying wetland conditions on the Client's 10 acres (Tatasaea 1995). Because wetlands were affected by development of the southern parcel, the properties are subject to a U.S. Army Corps of Ends (Corps) permit (No.95-4-01077).The Corps allowed the previous owner to f110.36 acre of Category 2 wetland on the southern parcel in return for constructing a new 0.54-acre wetland on the northern parcel. A wetland mitigation,plan was completed in 1996 to meet the requirements of the City and the Corps permit(Talasaea 1996). Historically, hydrologic conditions on the northern parcel ware influenced by drainage ditches tbat collected stormwater runoff from 3rd Avenue South and 5th Avenue South. In 2001.20021 the City constructed a new stormwater drainage system that replaced the drainage ditches associated with 1st Avenue South, 3rd Avenue South and 5th Avenue South. The new system consists of collection pipes and a stormwater detention basin located between 1st Avenue South and 3rd Avenue South and north of South 259th Street(Figure 1). A drainage pipe that will drain treated stormwater from the detention basin to the Green River has yet to be installed. The City's new storm drainage system. may be significantly affecting wetland hydrology on the northern parcel of the Client's property.With changed hydrologic conditions and development of the southern Parcel. the northern parcel may no longer be au appropriate location for the proposed wetland mitigation. i 8lgr+a!Sleao-ie, Ina Hydrolaiy and Wetland AssaumeM-•Draft 1 June .26. 2003 J II yLylIl � a 74 i 1+���`rm i��l I' \�,\ • / • I JAI 11 413�l'1 11'b i :� tills q�tl IIf t��� I I Il It I 1I � 1F SulilS I „ � 11. i i rEE�HI�\II it I i 11 M`1AI'IguIlI 14,1 IiJ i�� {I i l 5 `l9 HIP, 211 . l 1 1 T}}r I, ii�i f�'l lII p l�.r 1 r r nO"P �'VI 111 p9;1,;1: TAT iLI iV( f.YVT VVI iV YYUJ JVVVVV ViM rF Yn.unv•1\�v ( 1"IVY� 41 SO x ylnog onueAv pit Ca.F O It S 4 Of` +1,4 1 + ,i11411; # r # 41}� ,I,t; 1 1 { 14 1 4 r�rt�j 4 1 441t#'pry;4 I�t +4�+�f{'�i'1 y ` 4 y4,�ll11 14\41 41141�� ;+44, 1I +l41i�{r44144'dl {I4111� 11111+ 1111i4� {� } � 14 ,114 �# 1} r 4f + 11114N ,4 ' 4{4 141} 11411 , 41 1 1411 1144 G1� 1 y 1 yl 1441 ; i; { 1 r44111r1` 4 + �oe� i4}t�14114114 1 '44r41 �'4i1'41'1� 44 'il # 1'1 1411 1 1 1 }1441 ' 411 � 441rti;tlrilr { 4i �� ;ryryil41�t#1t t mums i; 1 1 ; 1 41[If 4 1 1114 114 1 1 41N 14 4 4 44 41 t 4 4 g 111 4'11� 141 4#r 1 114 4'�1'�+� 1� ` 411 4'f +i1} }11 i 414 1'♦'� 1414 41 '114 # # 1 O { Ili 1 , i141 41 t +14 1 , 1141 41 1 ;114 y 1 N 1 N14 y 1 1 11+ 4 b 4H14 1 [1 144 1 11 a N�144 ;tl1 14 1r� 141 { 41 4 1ri i4 11 1 1i� 44 }r y 4 t,41 44 4 , 4t'}11' 114i141i1+ �414 �414r14 �4t{yi44144 ' 11 �.11;' 1+�E144s 141 1� 14{ 1 4 4 4 41 1� 114 1 1 4 41 rlr i; 1 1 44 1]1 114 # 4 1a1 N 14 114 411i 411 4411 +I} 1'#11 1414 }� 1 4I1 4'{'{i +1� y4t 1 1� 1t414i 41I + 1 r� 1�14 114 14 '4414 4 4t'14 II tl '14+f 1 {'14 14� 1411 14 44 11 4 if 1 4 f 14111 4}1 t14 1141�4 41`1�� 4�'41441r1 111'+ 11i14t 114414t414 } 1141� 4 t1 l ; � 1 4 4 i1 tf 1 { 1 4 4 11 1 41} 4'11 444 }1 ` 4141t Ii 14f s 4 #14 4114 +1 414 1 04D r 00 a® N 111111414 t } 1 },4'114�i141'°�1 i4,{4i1{ 444 t1 z 44 4 4114ri� 1 41 41 ITi' `� ` Q 411 4 it IV � 1111 11 14 ' 411 4 1114 1 {1 4147 1414 11 4414tri�,•4 14�; 1 j4f 1 iy11114 11 1 41414 14� 44+ 1 t 1 411 ii 44 1 1 1� 14; 1 14411 1� 14 4 1 #44 41 11441#� 44141,11l44i�414114' t c u 4 1 4IRMS enueey y19 S $ 3. METHODS To assess current hydrologic and wetland conditions at the site,a SHAPIRO biologist visited the site nine times during March and April,2003,During the ftt site visit, on Match 6, the biologist performed a reconnaissance-level wetland inspection to identify any significant changes since the 1955 delineation report(Talasaea)and installed six piezometers to gather hydrologic data. To characterize wetland oonditions, sample plots.were established in wetland and upland areas based on wetland boundaries identified in the Taiasaea delineation report (1995). Sample plot locations are shown on Figure 2. Soil conditions were examined for hydric indicators, and horizons were described Organic content was estimated visually and texturally. Soil colors were determined using aMunsell soil color chart (Munsell Color 1994). Data collected at earls sample plot were recorded. Vegetation communities at the site were identified. At each sample plot, al[ herbaceous plant species within a 5-foot radius were idcntilled, and the percentage of ground covered by each, species was estimated All shrubs, saplings, and trees within a 30-foot radius also were identified and their ground cover estimated. Levels of inundation or saturation within the soil pits also were recorded. Cuurentwetland boundaries were not flagged or surveyed. Each piezometer is a 3-inch-wide polyvinyl chloride (PVC) pipe with holes spaced every 3 to 4 inches along its length and a wire mesh screen wrapped around its base, A soil bucket auger was used to manually dig six, 6-inch diameter holes 30 to 36 inches deep, and the piezometers were inserted into the holes. The piezometers were a few inches longer than the holes were deep so the piezometers would extend a few inches above ground level. The gaps between the piezometers and the walls of the holes were filled with sand. The area from: the surface of the ground to a depth of about 6 inches was filled with bentonite.PVC caps were placed on the piezometers and fluorescent flagging was hung near them to identify their locations durinj& the monitoring period (locations are shown on Figure 2). The water level depth below the ground surface in each piezometer was measured weekly for eight weeks following installation, for a total of nine monitoring visits. 4. RESULTS 4.1 Summary of References A wetland delineation report completed in May 1995 identified two wetlands on the Client's northern parcel (Talasaea 1995) and one on the Client's southern parcel The following information is a summary of the wetland conditions described in that report. Approximate wetland boundaries as identified in the 1995 report are shown on Figure 2. Wetland A was descabed as a 0.69-am isolated palustrine forested wetland in the northwest corner of the northern parcel, adjacent to 5th Avenue South. It extended beyond the northern boundary of the parcel, and was rated a Category 2 wetland based on the Kent City Code. S99nal zleatHa, ZnC. Hydrolasy and Wetland Assessment— prq/t 4 Jane 26,2003 ii� .�V, iVY� YV.1Y �VVV JV VV VV V-FI Y,r ����.. -� 11•.4V VJ F Wetland B was described as a 2.87-acre isolated palustrine forested wetland is the northeast portion of the northern parcel. According to the 1995 report, a berm that ran slang the north property line separated Wetland B from the undeveloped property to the north. Wetland B was bounded on the east by 3rd Avenue South. A small portion of Wetland B, about 0.8 a=, extended onto the southern parcel. Wetland B was rated a Category 2 wetland based on the Kent City Code, Wetland C, on the Client's southern parcel, and the approximately 0.8 acre of Wetland B that extended onto the southern parcel, were filled under a Corps permit (No. 95-4-01077) in return for constructing a new 0.54 acre wetland on the investigated(northern) site. 4.2 Wetland Evaluation SHAPIItO investigated the site on March 6,2003.The 5-acre,recbwVAar parcel is generally flat. lautorconnecting trails traverse the site, which is littered with garbage and debris, including tarps, mattresses, couches, clothing, and 50-gallon drums. The site is undeveloped, as is the parcel to the north. To the south is a 5-acre developed parcel. The site is bordered by Sth Avenue South on the west and 3rd Avenue South on the east. The land west and east of these two roads, respectively,is zoned industrial or commercial(Fig=e 2)1 Sample plots were established in wetland and upland-areas of the site based on the wetland boundaries identified in the Talasaaawetland deliueatian report (1995). Sample plots 15 21 and 7 were established in Wetland B. Sample plots 3 and 4 were established in Wetland A. Sample plots 5, 6, and 8 were established in uplands. Sample plot locations are shown on Figure 2. Saanple plot data, including soil. (Table 1), vegetation. (Table 2), and hydrology (Table 3), are provided below. Sample plot data from the Talasaea wetland delineation report is summarized in Table 4, Table tl: Sample Plot Spa Data 2003 Sample Location Soil Horizon. Matrix Mottle Texhue Plot awales) Color Color 1 Wetland l3 0 to 14 10YR 4/3 1 OYR 516 silty olay loam 14 to>18 l OYR 512 JPYR 5/2 dhv play loam 2 Watland B 0 tp 14 1 OYR 4t2 1 OYR 516(faint) silty clay loam 14 to>18 10YR 5/2 IOYR 516 SUN Clay loam 3 Watlaad o to>a IGYR 50 10YR 514 to 1 OYR 5/6 silty Clay loam 4 Wetland A. 0 to>1 s 10YR 4/2& 1OYR 5/2 1 OYR 514 Bilty clav loam 5 Upland 0 to 8 10YA 4/2 Bane silty clay loam 8 to>18 Ign 4/3 IM 4/6 faint sit clay loam 6 Upland 0 to 8 1 OYR 4/2 none silty clay loam 8 to >18 1 OYR 413 none san lozm 7 Wetland B 0 to 14 l0n 4/3 to loYR 4/4 none silty clay rosin 14 to>18 20YR 5/2 10YR 5/2 (faint) silty RI&Y loam i 8 Upland 0 to 8 1 OYR 4/2 none silty clay loam to>18 lOYR 4/3 lOYR 416(faint) --silty olay loam Signal Blactnc, Inc. Hydrology and Wetland Axtepw d—,pre 5 ,Tune 26,2003 N v e� • • `9e, C C ` o o a n ill .moo b a I y A b z 88 178 s 8 o ; Hip ts tr n tC n b o PQ a -C� Q . ? Al n b a It 4 u Vj ?d Jd • � -� �+ N c�1 C �n w n ep 0 Table 3: Sample Plot Hydrology Data 2003 Sample Plot Hydrology 1 no saturation or freestanding water to 25 inches 2 no satixtation or freestanding water to 24 inches 3 no saturation or freestanding water to 28 inches 4 no saturation or freestanding water to 28 inches 5 no saturation or freestanding water to 28 inches 6 no saturation or freestanding water to 28 inches 7 no saturation or freestanding water to 28 inches 8 no saturation or freestanding water to 25 inches Table 4: 1995 Talasaea Wetland Defteation Data Summary Soil Colors Ma tlea Vegetwon. 'Rydmlogy Wetland Arew 10YR 4/2 IM 4/3 black cottonwood No saturation or Desstm iduag water A and 8 10YR 512 and Fobt bleak b",%om observed.Hydrology based on well Douglas'spina dat& red-osier dogwood salmonbcaiv Upland Arm 1 OYR 4/2 Faint black cottonwood No saouation or Fm binding water 1 OYR 4/3 blwk hawthorn obaesved.Hydrology based oA well 1 OYR 5/3 5oouler willow data. beaked haniza t rAnalayan biwkbcay red osier dogwood seed oauarygmas ashonberry Soils are typically grayish brown (IM 5/2) to dark grayish brown (I OYR 4/2) in the areas of the site identified as Wetland A and Wetland B(Figure 2).Mottles are gayish brown (l OYR 5/2) to yellowish brown (I OYR 516). The upland areas of the site ate dominated by dark grayish, brown GOYR 4/2)to brown(I OYR 413)soils with faint oar zo mottling. Dominant tree vegetation at the'site is black cottonwood (Populus babaW era). Red-osier dogwood (trornus sericea) is 'the dominant-shrub species in the wetland areas and Himalayan blackbany(Rubes procerus)is the dominant shrub species in the upland areas. Ground cover in most of the site is bare ground with patches of reed canarygrass (Phalwis arimdinacea). A cozaplete list of plant species observed during the site visit is provided in Table 5. Hydrology information from the sample plots is documented from a greater depth than what is typically evaluated during wetland delineations (usually about 18 inches) because the data was t gathered during the installation of the piezometers.None of the eight sample plots had saturation or freestanding water wi#ain 24 inches of the ground surfaoe on March 6,2003. Signal Elactrlc, Ina ' Hydrology and Weiland Ar-moment-,Dm t T June 26, 2003 _ ___ r -rr,rr JiW 1rIL IrVLVII\Y..' I I1VIL iL . 1 • rrr- Table 5, Plant Species Observed During the 2003 Site Visit Common Name(ScienffwName) Indicator Status' Trees and Shrubs black cottonwood FAC red-osier dogwood FACW English ivy(Hedera helix) FACU holly(Ilex aquifoha) FACU giant knotweed(Polygonum sachalineme) FACU Himalayan blackberry FACU salmonberry • , FAC+ red elderberry(,Sambums racemosa) FACU Douglas geirea FACW Crass and Herbaceous colonial beotgrass FAC slough sedge OBL reed canarygrass FACW creeping bittfmaup FACW 1 These cuagorias,tefarad to as the'wvedand indicator statue"(from the wettm to driest habitats) em ae follows: obligate wetland(OBI)plants;facultative wetland(FACW)plants;facultative(FAC)plants; facultative upland (FACE])plante; and obllgato upland[UPL)plants. 4.3 Piezometer Monitoring Six piezometers were installed in wetland and upland areas of the site, based on the wetland boundaries identified iu the 1995 Talasaea wetland delineation. report (Figure 2). Piezometers 1 through 6 were placed in the corresponding sample plots that were established during the wetland evaluation. Piezometers 1 and 2 were placed in Wetland Area B.Fiezometer 1 was installed in the center of a small patch of slough sedge, about 10 feet by 15 feet Piezometer 2 was installed in a shallow ditch, about 2 feet deep and 4 feet wide,that eaters the site from 3rd Avenue Soutb and appears to have conveyed stornawater runoff from that road prior to installation of the new stormwater conveyance system. Water was not observed 1u the ditch during the study period. Piezometers 3 and 4 were placed in Wetland Area A in areas domiinat 4 by wetland vegetation such as reed canarygrass,spirea, and red-osier dogwood. Piezometers 5 and 6 were installed in upland areas dominated by Himalayan blackberry, a non- native,upland shrub species. Signal Llectrla, Ina. Nydrology and Watland AavaaMM-npyo 8 June 26, 2003 it - -- -- -- ---------- _...- --..._ A SHAPIPO biologist collected piezometer data wer ly in Match and April 2003.Depth of each piezometer is shown in Table 6. Data collected during each of the nine site visits is shown in Table 7, Standing water was not observed in piezomcters 3, 4, 5, and 6 during the monitoring. Average depth of standing water for March and April is shown in Table 8. Table 6; Plezometer Depth Below Ground Level Qucbes) Piezometer Depth below ground surface 1 32 2 36 3 30, 4 34 5 35 6 35 Table 7: Plezoneter Data 2003--Depth from Ground Surface to Standing Water (Inches) Piezometar Match 5 March IS Match 19 Maroh U Apr114 April 11 April 16 ApnI 25 Apri130 1 dry 31 27 12 22 19 20 22 37 2 dry 13 15.5 1 11 8 15 14 23 3 dry dry dry dry dry dry dry dry dry 6 dry dry d'y diy dtY dry dry dry dry s Table 8r Piezometer Data 2003 Average Depth from Ground Surface to Standing Water (inches) Piezometer March April March and April 1 26 23.8 24.9 2 16.4 14.2 15.3 3 >30 > 30 >30 4 >30 >30 >30 5 >30 >30 >30 6 >30 >30 >30 Note; >30 inch average depth based oa depth of piezoAmet=wtth'no standing water observed. Signal BleoMo, Ina Hydrology and Wedand Aaavameu-Dmf3 ➢ June 26, 2003 r'AtzM 14 l ' Appendix B in the 1995 Talasaea wetland delineation report contained well monitoring data performed at the site in February and March 1995. Information from Appendix B is summarized in Table 9.Well,monitoring locations from the Talasaea report are shown on Figure 2. Table 9: 1995 Well Mon#oring Data-Average Depth kom Ground SmIace to Standing Water (inches) Wall# February March February and March 1 16.5 20.4 19.5 2 11.3 7.9 9.6 3 5A 12.9 9.1 4 13.5 12.9 • 13.2 5 9.7 .11.0 10.3 6 5.3 13.5 9.4 7 11.5 19.7 15.1 8 12.0 15.5 13.8 9 4.8 12.0 8A Sou=e: Talmaea 1995 Daily precipitation data for the months of February, March, and April 2003, includiug the number of days with measurable precipitation per month, is shown in Table 10. Table 11 provides monthly precipitation data for February,March,and April,imeluding total precipitatiom per month in 2003 and 1995, and average monthly precipitation from 1931 to 2003. Table 10: Daily Precipitation Data for the Mouths of February,March, and April 2003 (inches) Day of the Month Febmary+ March April 1 0.01 0.00 0,17 2 0.01 0.23 0 11 3 0.07 0.00 0.25 4 0.00 0.00 *trace 5 0.00 "trace D,ld 6 0.00 0.00 . beta 7 0.00 0.49 0.24 8 0.00 0.13 0.32 9 0.01 0.83 trace 10 0.00 0.08 0.02 11 0.00 0.97 *0.05 12 0.00 0.99 0.06 13 0.00 *0.21 0,7 14 0.00 0.06 trace 8ouro0: Seattle 2003 ' PlezamaW oollcotion days In bold Srgna!,Elewdc, Ina Hydrolog•mid WkrIand Aaeavft Kt-Drvfi 10 June 26, 2003 Lif LOIAM + WO.LV iJJJJJG.,JJO 7LVIlf'1L CLGvI RL I"iil7t jJ 1 1 'fable 10. Continued Day of the Month Fehntsry Match April 15 0.33 D.09 trace 16 0.71 0.14 Mace 17 0.04 0.00 0.02 18 0.01 0,12 *0.0 19 0.05 *0.24 trace 20 0105 0111 0.02 21 0.39 0.92 0.19 22 0.06 0,55 0.02 23 0.0 0.08 0.22 24 0.0 0.02 0.16 25 0.0 0.05 *0.0 26 0.0 *0.12 0.01 27 0.07 dace 00 28 - 0.0 0.0 29 0.0 0.02 30 0.18 'OA 31 0.09 #Days with,measurable 13 24 25 pc' 'ratio 9owee: Spathe 2003 0 Piesotnew aolleotion days in bold Table 11: Precipitation Data (Welkes) Total Precipitation par Month Total Precipitation per Average Monthly Precipitation (2003) Mouth(1995) (1931 to 2003) February 1.76 4.97 4,17 marcb 6.34 4.07 3.72 Apffl 2.79 2.05 2.56 Source: Seattle 2,MS; Washington 2043; TLInaea 1995;Wssbitgton 20D3 S. DISCUSSION 5.1 Wetlaud It vabuttion Overall soil, vegetation, and hydrologic conditions observed in 2003 am consistent with those observed in the wetlands and uplands as deiiteated in the 1995 TWmaea wetland delineation report. The site is in the bistorical tloodplain of the Gram River.Dark grayish brown (lOYR 4/2) soils were observed in both upland and wetland areas (Tables 1 and 4). Vegetation communities are consistent with those documented in the 1995 Talassea wetland delineation report (Tables 2 and 4). Vegetation in Wetlands A and B is dominated by black cottonwood and red-osier dogwood, Himalayan blacicberry is the dominant vegetation in the site's upland areas. Hydrologic conditions in 2003 were consistent with those documented is the 1995 wetland delineation Slgnal,87eorric, Inc. Hydmiogy and Wetland Aaserammd-D qR i I June 26, 2003 .... Olen`IHL C.LGLr�Ri, rr�tat lb report. Saturation and/or freestanctibg water were not observed in 1995 or in 2003 (Tables 3 and 4). The results of well data documented in the 1995 report are discussed in the piezometer monitoring section below. Soils and vegetation at Sample plots 10 25 3, 4, and 7 are hydric, according to wetland classification criteria(Tables 1 and 2).Hydrologic conditions at these sample plots do riot qualify as hydric according to wetland classification criteria(Table 3). Soils,vegetation, and hydrology at Sample Plots 5,6,and 7 do not qualify as hydric, according to wetland classification criteria(Tables 1,2,and 3). 5.2 Piezometer Monitoring Standing water was not observed in piezometers 3, 4, 5, or 6 during the monitoring (Table 7), Standing water was not observed in piezometers 1 oz 2 during the first day of uonitt Fing (March 6). The average depth of standing water in Piezometer 1 during the monitoring period was 24,9 inches (Table 9). Piezometar 2 was placed in a shallow ditch that appears to have conveyed stormwater runoff £tom 3rd Avenue South prior to 2002, when the City installed a new stormwater conveyance system. Water was not observed in the ditch during the monitoring period.Piezometer 2 had standing water 1 inch below the ground surface on March 26 (Table 7). During the other eight data collection days, standing water in Piezometer 2 was at least 8 inches deep.The average depth of standing water ire Piezometer 2 during the monitoring period was 15.3 inohcs(Table 8). Average depth of standing water in the nine wells that were monitored in 1995 ranged from 6.4 inches to 18.5 inches(Table 9). Piezometer monitoring in 2003 occurred during March and April. Well data collection in 1995 occurred during February and March(Talasaaa 1995). In 2003, precipitation in March and April was above average,based on climate data from 1931 to 2003 (Table 11). Precipitation in Match was more than 2.5 inches above average and in April was 0.23 inch above average. In 1995, precipitation in February and March was also above average (Table 11), more than 0.9 inch in February and 0.35 inch in March. The cumulative amount of precipitation during the two months of monitoring in 2003 (MaX4 and April) was 9.13 inches. The cumulative amount of precipitation during the two months of monitoring is 1995 (February and March) was 9.04 inchea (Table 11).-Thus, the difference ur precipitation levels during the 2003 and 1995 data collection periods was less than 0.1 inch As shown in Table 11, based on precipitation data from 1931 to 2003, average precipttatlon for February is 4.17 inches, for March is 3,72 inches, and for April is 2.56 inches, Based on this, cumulative precipitation during the two months of monitoring in 2003 (March and April) was 2.85 inches above the average of 628 inches. Quautative precipitation during the two months of monitoring in 1995(February and March)was 1.24 inches above the average of 7.89 inches. MVTal TSTB PIGI Inc, Hydrology and Mefkmd Anewmen!-Dro 12 dune 26, 2003 err �..r�.vu-. uu.�u rvvurvv....v Ji.M xv- i..�w n•+. fNUL 1f { A comparison of the average depth of standing water Collected during the 2003 emd 1995 monitoring periods is provided in Table 12. A&shown,within the three areas of the site (Weiland A. Wetland B, and the upland exea), the dff&mce in the average depth of standing water observed in 1995 and 2003 is significant In Wetland A and the upland area, no standing water was observed in 2003. In Wetland B, the average depth of standing water was greater ir, 2003 than in 1995 in all of the data collection points. The average depth of standing water in Piezometer I is more then double the average depths of Wells 6 and 9 and more than 10 inches deeper than Well 8. Table 12: Comparison of 1995 Well Data and 2003 Piezometer Data Wetlands Average Depth in inches Wetland A Piezometer 5 (2003) > 301 Piezometer 6 (2003) > 301 won 1 (1995) 18.5 wall(1995) 9.6 Well 3 (1995) 9.1 Well 4(1995) 13.2 Well 5 1995 10.3 Wetland B Piezometer 1 (2003) 24.9 ;Piezometcr 2 (2003) 15.3 Well 6 (1995) 9.4 Wall 8 (1995) 13.8 Well 4 1995 8.4 Upland Area Piezometer 3 (2003) > 301 Piezometer 4 (2003) >301 Well 7 199 15.1 1 No Standing water was obownd.Average depth fe ldemdfled as>30 inches based on the depths of the piezometera. 6. CONCLUSIONS Soil and vegetation at the site appear consistent with conditions that were documented in the 1995 `1'alasaea wetland delineation report. Soil and vegetation data collected at the site in 2003 are generally similar to the sample plot data recorded for Wetland A,Wedaud B, and upland areas of i the site in the 1995 report S1gna1 S1eatMq Inc. A *alov and Medland Atowemew—DnO 1! June 26, 2003 ..i'I iVl YVV7 YJ.aV LJJJ JJY.IVV JiM111"IV .�V�V.1\iV 1 11\Iln 1U Hydrology-at the site appears to have been influenced by the installation of a stormwater drainage system in 2002. Drainage ditches associated with 3rd Avenue South and 5th Avenue Sout were replaced with collection pipes and a stortawater dateatiou basin that divert stormwater away from the site. It appears likely that wetland hydrology at the site was supported by stormwater runoff associated with 3rd Avenue South and 5th Avenue South. Cumulative precipitation during the two months of monitoring in 2003 (March and April) was less than 0.1 inch greater than the cumulative amount of precipitation during the two months of monitoring in 1995 (February and March). Cumulative precipitation daring both monitoring periods was above average% 1.22 inches in,1995 and 185 inches in 2003. A comparative analysis of well data collected in 1995 and piezometer data collected in 2003 shows a significant difference in the depth of standinng,water below ground surface between 1995 and 2003. All six of the piezometers were established at a depth of 30 inches or greaten.Four of the six pie2ometers were dry throughout the 2003 monitoring period. Average depth of sliding water in the nine wells that were monitored in 1995 ranged from 8.4 inches to 18.5 inches. Because of the ebange in hydrologic conditions, the site no longer appears to be an appropriate location for the proposed wetland mitigation. It is SHAPIRQ's mcommandation that a different wetland mitigation site be identified to moot the requirements of the Corps permit (No. 95-4- 01077). i signal.&1ecfnrC Inc Zt4mlo&and Wedand Astawnw-DrgR 14 June 26. 2003 1L/ iJJ LVVy VGi.lU LJJ...Y.dV.1JY JiMI\1"1L LYL.V 11�14" r!'M1IC LJ • REFEP"CES City of Seattle(Seattle).2003. Climate Summary Web Site. URL h�,i�vw.beauti fulaeattle.com/ix�dex.htm. Munsell Color, 1.994. Mwasell Soil Color Charts. Kollmorgen Corporation,Baltimore,,Md. Talasaea Consultants. June 1995. Wetland delineation and study report. Woodinville,Wasli Talamea Consultants,December 1996. YzncentMinnella prpperty final wetland mitigation plan. Woodinville,Wash. Washington Climate Summary Web Site(Washington).2003,MMJ1=/lww7,wrcc.dajgdu. ' I I 1 final Mcobia, Inc Xydrolagy and Welland dsseasmmd-Dro I S dime 26, 2003 x ^. elm a oZN � a �n z EXHIBIT 4 0 uol Page 1 of 4 H CL ail I nii g U9 na � � yly4w+ gw OgR N • , _ as� K a �J O Bic� EggW S UElm �o0a , F���o p e ra tl • Z z m�o o� I ---sue--- -- w 10 In P x�d$JN �LiCe4CZ M 4 a �zFa?F-o61,1 mlrw wm— I' W If - ` tAM46 A z --------- _-- g I N 0 Ln + y e I ® A La B La C a `� = a o EXHIBIT 4 P a Ln z_ N Page 2 of 4 II ' • � M cl C) e � - • ,1 W ■E ,ems, • nA I < s w � x M ` i0 I a I i 0 C5 < n I J IMHUDN ze C❑CZf�9 Z hFzzzzjQza •— I �•�R __ p �'iU�70Z�,ctp A � . 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A,.�r: :Ai.4AW.RF1 �y. z4� oily a ................ - ���� :acsa Jr.........., E imc� g g i�z I I a o p 39 6 ��5 �'#�; rsai p W 9 ' uj z- arrr mm s I Y BI yVz� � EXHIBIT 5 Form Approved REPORT DOCUMENTATION PAGE OMB No. 0704-0186 r bGolmumo In amnlsesllmele toavarapa permaporue.n udhg Woorra forrevlewlnp Nudrunons,aaarohmg sousing seances,gathering and mania date needed.and mngetlnp and mleMng We onllecmn of Informatlnn.Send mmwds rapaMnp lhla buionasdmals ormyolharaspeetef Uds odleceon ofinfamatlorr.InrSdNpwppasdarV fornduarp this Widen to DepMmenlof Dafeass,Wathinglan headquarters SeMoes.DYaaorata for Informagan Operaaons and Reports(1170"jiisj 721516Rereoo Daft K*nM,Sella 1204.Arilnpton,VA 2=- 430L Respondents should be amne that noWthstandit arty other pmvlam of law,na paam shall be whlact m any penally,forfesing to On*Will a adkotlon of a=aftn if li dose notdbplaya ounendy vaNON15ccaatlaanber PLEASE DONDT11MRNYOURPORN TO TNl AEOYa A13DREM 1.REPORT A rom- o A 612000 Final Report 4. T So.CONTRACT NUMBER Accessing and Using Meteorological Data to Evaluate Wetland Hydrology 5b.GRANT NUMBER Sc.PROGRAM ELEMENT NUMBER 9.AMOR(S) Gd.PROJECT NUMBER Steven W.Sprecher,Andrew G Warne 're.TASKNUMBER 5f.WORK UNIT NUMBER 7.PERFORMING ORGANIZATION8.PERFORMING aWNIZATION REP NUMBER U.S Army Engineer Research and Development Center Environmental laboratory ERDC/EL TR-WRAP-00-1 3909 Halls Ferry Road Vicksburg,MS 39180.6199 U.S.Army Corps of Engineers Washington,DC 20314-1000 O M N R'S REPMT NUMBER(S) Approved for Public Release;distribution is unlimited 13.SUPPLEMENrARY I&ABSTRACT The Corps of Engineers Wetlands Delineation Manual recommends that"preceding weather conditions must be considered"when interpreting observations of water at possible wetland sites Sources of meteorologic information are described in this report,and suggestions for analysis of relationships between local and regional weather and site hydrology are provided Monthly precipitation data from more than 8,000 National Weather Service(NWS)stations have been analyzed,compiled,and made available on the Internet by the USDA National Water and Climate Center in the format of WETS Tables. These tables report 30`s and 70th percentileexceedence frequencies for monthly precipitation,which generally define the range of normal precipitation. Suggestions for presentation of WETS Table data are provided. A method for calculating rolling sums of daily rainfall to enhance the accuracy of hydrologic assessments of sites is presented. The USDA Natural Resources Conservation Service has devised amethod for systematically assessing antecedent weather conditions at a site;this method is described and suggestions to enhance the accuracy of this approach are provided Regional patterns of drought and precipitation excess can be tracked using the Palmer drought indices,the Standardized Precipitation Index,and/or real-time gauge data. Contemporary conditions are standardized as percenbles of long-term records at Web sites reporting these analyses for climate divisions in each state. 15.SUB.IECT TERMS Continu eM Hydrology Rainfall Wetlands Meteorology Weather WETS tables is.SECURITY CLASSIFICATION OF: 17.LIMITATION 18.NUMBER 19a.NAME OF RESPONSIBLE PERSON OF ABSTRACT OF PAGES a•REPORT T17AWRACT c.THIS PAGE 1W.TELEPHONE NUMBF(-inciadearea UNCLASSIFIED UNCLASSIFIED 96 gal Standard ornt ay.848) Preaeribadby ANSraW 230.1e 14. (Concludadl. The statistics of precipitation frequency analysis and some of the pitfalls in using site-specific and regional data are discussed. Analyses of regional precipitation patterns are probably sufficient when observations of hydrology are not quantified. Personnel engaged in projects requiring quantification of onsite hydrology,however,should gather precipitation data on or close to the site on a daily basis Daily data not gathered from official NWS stations should be compared with daily records from stations included in the WETS Tables network. These analyses should then be superimposed on the long-term patterns available from Web sites reporting regional analyses of Climate divisions. i Destroy Iles report when no longer needed Do not return it to the originator. I i Contents Preface.................................................................................................................vii Overview.............................................................................................................vni 1. Background Concepts....................................................................................... I 1.1 Why be concerned with antecedent precipitation....................................... 1 1.2 What is"normal precipitation"......................... .. .....................................1 1.2.1 "Normal precipitation"as a single value..........................................1 1.2.2`2tanges of normal precipitation"..................................................... 1 1.2.3 The three-decade base period...........................................................2 2. Range of Normal from the"WETS Tables".....................................................3 2.1 Accessing the WETS Tables............................_.........................................3 2.2 Important information in the WETS Tables..............................................3 2.3 Interpreting"zero"precipitation levels in the WETS Tables.....................5 2A.Graphical presentation of the information on WETS Tables.................... 5 3 Finding Recent Precipitation Data...................................................................7 3.1 Existing sources..........................................................................................7 3.2 Unified Climate Access Network (UCAN).... .................................. .....7 3.3 Using onsite rain gauges................ ..........................................................8 3.3.1 Rain gauge quality and location....................................................... 8 3.3.2 Interpreting onsite precipitation data.................................................9 3.3.3 Summary of use of onsite rain gauges.............................................I4 4. Evaluating Antecedent Precipitation Conditions at a Site............................. 15 4.1 NRCS Engineering Field Handbook.........................................................15 4.1.1.Background....................................................................................15 4.1.2.NRCS procedure for estimating antecedent moisture conditions at a site . . . ........................ ................................... 15 4.1.3. Comments on the MRCS method...................................................16 4.2 Method of rolling totals...........................................................................16 4.2 1 Background....................................................................................16 4.2.2.Procedure of 30-day rolling totals..................................................18 4.2.3.Determining whether tallied precipitation was within rangeof normal .......................... .. ...........................................20 iii 4.2.4. Comments on the method of 30-day Tolling totals........................20 4.3 Combined method of 30-day rolling totals and MRCS Engineenng Field Handbook weighting factors........................................................21 4.3.1 Procedure for combining the methods of 30-day Tolling totals and Engineering Field Handbook weighting factors........ ..........21 4.3.2 Comments on the combined method. .......... . ..............................21 4.4 General Observations on Assessments of Antecedent Precipitation.........23 5.Growing Season...............................................................................................24 6.Drought Analyses on the Interact.................................................................25 6.1 Preliminary nature of near-real time analyses...........................................25 6.2 Palmer Drought Indices............................................................................25 6.3 Standardized Precipitation Index......................... ....................................29 6.4 USGS Stream Gauge Data.................... ...................................................32 7.Geographic Variation in Precipitation............... ............................................36 8. Comparing Data from Monitoring Wells and Rain Gauges............................38 9.Statistical Background and Common Problems..............................................43 9.1 Gamma distribution• bitroducouan to the statistics of normal precipitation........................................................... ...............................43 9.2 Arid lands.............. ................................................................ ................ 45 9.3 Bimodal precipitation............................................................ ................. 46 10. Summary and Recommendations..................................................................49 10.1 Summary.................................................................................................49 10.2 Recommendations...................................................................................49 11,References.....................................................................................................51 Appendix A Addresses for Collection and Analysis of Meteorological Data..............................................................................................Al Appendix B NWS guide on rain gauges...........................................................B I AppendixC Forms........................................................................................_.CI Appendix D Comparison of probability distributions,for temperature and precipitation data.................................................................DI AppendixE Notation.......................................................................................El SF 298 iv List of Figures Figure 1. WETS Table for Grand Island,NE......................................................5 Figure 2. Graphic presentation of WETS Table mformation plus monthly precipitation totals for a particular year.................................6 Figure 3. Example of comparison of data from an unofficial weather station..10 Figure 4. A.Ranges of normal for monthly precipitation at three NWS stations in Indiana. B.Actual monthly precipitation totals at three NWS stations and a research station in Indiana, superimposed on a graph of average range of normal monthly precipitation at the NWS stations.....................................................13 Figure 5. Worksheet to determine whether precipitation was within the range of normal prior to a site visit................................. .................I7 Figure 6. 30-day rolling totals of precipitation at Grand Island,NE, overlaid on graph of daily precipitation and monthly precipitation.. . ............. .... ..............................................................is Figure 7. Three 30-day periods prior to May 15,superimposed on Figure 6....22 Figure 8. Omwmg season information as presented m WETS Tables, forWooster,OR.. ................ ............................................................24 Figure 9. Palmer drought indices for Climate Division 5,NE(includes Grand Island)for 1991......... ............................... ....... .......... .........26 Figure 10, Example of Palmer Drought Severity Index by climate division for the Nation from provisional data at the Climate Prediction Center........................... ...................................................................28 Figure 11. Period of record for Palmer Drought Severity Index for Climate Division 5,NE(includes Grand Island)...............................30 Figure 12. Example of precipitation percentiles for Division 1 of Nevada, for periods of 1 to 72 months ...................... . ............................33 Figure 13. Example of USGS streamilow graph at USGS website, including table of exceedence thresholds..... ...................................34 Figure 14. Precipitation patterns across the Sierra Nevada divide expressed as percentiles of monthly precipitation.............................37 Figure 15. Daily precipitation and water well data near Columbus,OR, 1997..39 Figure 16. Daily precipitation and water well data near McHenry,IL, 1995-1996..........................................................................................40 v Figure 17. Histogram and gamma distribution for same set of precipitation data,Aprils 1961-1990,Grand Island,NE... ............. .....................44 Figure 1 S. Histogram of July precipitation at Mojavd,CA,for 1961 to 1990 ...46 Figure 19. Frequency distributions of June precipitation at Raleigh,NC...........48 List of Tables Table 1 Upper and Lower Percentile Thresholds for Middle Ranges ofPrecipitation Models........................................................................2 Table 2. Daily Precipitation and 30-day Rolling Totals for Jan-May 1991 at Grand Island,NE. ... ....................................................................19 Table 3. Comparison of Engineering Field Handbook Method and Combined Method,Grand Island,Hall County,NE, 1991................22 Table 4. Palmer Classes for Wet and Dry Periods...........................................29 Table 5. Exceedence Thresholds and Percentiles for SPI Values....................32 Table 6. Characteristics for Contrasting Weather Stations in the Tahoe/Reno Region...... ....................................................................37 A Preface This report was authorized and funded by Headquarters,U.S.Army Corps of Engineers(HQUSACE),as part of the Wetlands Regulatory Assistance Program (WRAP). HQUSACE representatives for this report were Mr. Charles Hess, Chief,Operations Division(CECW-0);Mr.John Studt,Chief,Regulatory Branch(CECW-OR);and Mr.Ted Rugiel,Regulatory Branch(CECW-OR). Dr.Russell F.Theriot,U.S.Army Engineer Research and Development Center (ERDC),Environmental Laboratory(EL),was the WRAP Program Manager. Mr.Made Smith,HQUSACE Regulatory Branch, was the wetland delineation point on contact. General supervision of this work was provided by Dr.Moms Mauney,Chief;Wetlands Branch,EL;Dr.Conrad Kirby,Chief Environmental Resources Division,EL;and Dr.John Keeley,Director,EL. The report was prepared by Dr.Steven W.Sprecher,U.S.Army Engineer District,Detroit,South Bend,IN,and by Dr.Andrew G.Warne,Texas Bureau of Economic Geology. The authors wish to acknowledge the efforts of the following people,without whom this report would not have been possible:Phil Pasteris,USDA National Water and Climate Center;Dr.Jay Grymes,South Regional Climate Center, Dr.Jim Richardson,North Dakota State University;Dr.James Wakeley,ERDC; Don Woodward,USDA Natural Resources Conservation Service;and,for his administrative assistance,Dr.Russell F.Thenot,ERDC. At the time of publication of this report,Dr.Lewis E.Link was Acting Director of ERDC,and COL Robin R.Cababa,EN,was Commander. This report should be cited as follows: Sprecber,Steven W.,and Warne,Andrew G. (2000). "Accessing and using meteorological data to evaluate wetland hydrology;"ERDC(EL TR-WRAP-00-1,U.S.Army Engineer Research and Development Center,Vicksburg,MS. Al OVERVIEW ' Investigators of wetland hydrology need to know whether they are malting their observations during normal weather conditions or during abnormal conditions of drought or excess precipitation. Such decisions require knowledge both of current precipitation inputs and of the frequency distribution of precipitation over the long-term record at or near the site.Information pertinent to accessing and using these meteorological data to evaluate wetland hydrology is presented in various sections of this report. Also,much of this information is now easily available on the Internet at the Websites shown below. SITE-SPECIFIC FREQUENCY DISTRIBUTIONS OF PRECIPITATION The USDA National Water and Climate Center publishes the ranges of normal monthly precipitation for over 8000 National Weather Service(NWS)weather stations.These analyses are called WETS Tables and are available for one to several weather stations in most counties in the Nation. The range of normal is reported as a"30 percent chance will have less than"(30"percentile)and a"30 percent chance will have more than" (70"percentile).The WETS Tables provide the user with the ability to determine whether precipitation inputs were within the range of normal at a particular NWS weather station and,by inference,in the immediately surrounding area These tables are discussed and available at: WETS Tables Section 2 htty://www wee nres.usda.gov/water/wetlands htnrl SITE-SPECIFIC REAL-MIE DATA The WETS Tables do not supply real-time precipitation data.The National Water and Climate Center (NWCC)is working on an Internet Web site(UCAN)that will publish real-time data for the 8000+ weather stations used in the WETS Tables,but until that site is established,rainfall records for the current and immediately preceding months are most readily obtained from State Climatologists and the Regional Climate Centers.They can be contacted at: State Climatologists Section 3.1 http://www.nede.noaa.aov/ol/climate/aase.html#STAT Regional Climate Centers Section 3.1 http,.//met-www.cit.comell.edulother rcc.html Weekly and monthly precipitation data for approximately 225 cities in the Nation can be obtained at the following Web site. Click on"Weekly Precipitation Table"or"Monthly Precipitation Table." Climate Prediction Center Section 3.1 http://www.coc.uceri.noaa gov/oroducts/analysis monitoring%dus/Drct) temp tables/ UCAN(site in progress) Section 3.2 htto://www.wcc.nres.usda aov/bbook/bb20 html viii ONSITR RAIN GAUGES Onsite rain gauges are occasionally used at projects in order to document precipitation patterns that may not be the same as those recorded at the nearest NWS stations included in the WETS Tables. To assure reliability,data collected onsite must be compared to the long-term precipitation record collected at NWS stations.A method for comparing onsite data with NWS data is presented in Using Onsite Rain Gauges Section 3.3 Portions of NWS Observing Handbook No.2 Appendix B EVALUATING ANTECEDENT PRECIPITATION The Natural Resources Conservation Service(NRCS)Engineering Field Handbook uses monthly precipitation data in conjunction with the WETS Tables to evaluate the preceding two or three months' precipitation input;the major weakness of the NRCS method is that it does not evaluate daily changes in precipitation patterns,especially for the current month of analysis.A method of computing 30-day rolling totals has also been devised to incorporate daily data into the analysis,but this method considers antecedent precipitation for only 30 days.Therefore,a third method is presented that combines the methods of the NRCS and 30-day rolling totals.These methods are discussed as follows: Hydrology Tools Method Section 4 kitty://www,wee.nres.usda.eov/water/auaUt�/tet2i h drolog.html 30-day Rolling Totals Method Section 4.2 Combined Method Section 4.3 THE REGULATORY GROWING SEASON The growing season is defined for wetland hydrology on the basis of soil temperatures,which in turn are estimated based on NRCS reports of 50 percent likelihood of last and first 280 F frost.These dates are available in NRCS soil survey reports,but more current dates are available in the WETS Tables. i Growing Season Dates Section S http://www.wcc_nice.usda.z"water/wetlands.htmi DROUGHT ANALYSES ON THE INTERNET Several Web sites present real-time data on drought and precipitation excess.These data are presented for Climate Divisions,which are regions of states that are meteorologically siaular.The advantages of these drought indices are that they are statistically based information available for the current or preceding month.The disadvantages are that they are not site-specific and that the real-tune data have not undergone official quality control procedures The most widely used drought index is the Palmer drought index,which evaluates evapotranspiration and soil water content as well as precipitation.The Standardized Precipitation Index avoids some of the assumptions of the Palmer Index and provides frequency analyses for twenty different time periods leading up to a month of observation,ranging from one month prior to five years prior.The US Geological Survey reports percentile frequency analyses of EX stream gauge levels around the Nation,which often serve as independent measures of climatic patterns. The appropriateness of individual tools to a specific site depends on the hydrologic controls of that site. Wetlands with a strong groundwater control need to be assessed with some of these longer term drought indices as well as with the WETS Tables.The drought indices are discussed and available at: Palmer Drought indices Section 6.2 Previous month and prior http://www.ncdc.noaa mov/ontineprod/drought/main.htmi Current week(provisional) htto•//www cpc ncep uoaa.aov/products/analysis monitonng/reeional monitoring/nalmer.g_if Standardized Precipitation Index Section 6.3 Percentiles for climate divisions http://www.wrec.sage.dri.edu/spi/spi.html National and archival bttp:/lenso.uni.edu/ndmc/watch/watch.htm Stream Gauge Analyses Section 6.4 http://water.usgs.goy/rcaltime.htmi SPATIAL VARIATION IN PRECIPITATION Spatial variability of precipitation is greater for individual storms than for precipitation averaged over a month or season.The National Climatic Data Center(NCDC)estimates missing values in weather data by interpolating between reporting stations within 30 miles.If a project does not have an onsite ram gauge,one should estimate monthly precipitation by averaging or interpolating between nearby NWS weather stations. Geographic Variation In Precipitation Section 7 COMBINING DATA FROM MONITORING WELLS AND RAIN GAUGES Data from shallow monitoring wells can be overlain on time series plots of daily precipitation data. Thirty-day rolling totals can also be plotted on these graphs. These graphs serve to clarify the relationship between local precipitation and site hydrology and provide a basis for determining the long- term hydrology of a site. Monitoring Wells and Rainfall Data Section 8 STATISTICAL BACKGROUND TO PRECIPITATION FREQUENCY ANALYSIS Precipitation data do not fit a bell curve but instead St a gamma distribution.The reason for this is that a site cannot experience less than zero precipitation in any day or week or month,but in theory it can always experience a larger rainfall amount than the last record high. Consequently,the frequency distribution is skewed to the right.Precipitation frequency distributions are skewed more strongly in and regions and for short-term analyses(for example,a month vs a year),These and related problems are discussed at: Statistical Background Section 9 x i 1. BACKGROUND CONCEPTS 1.1 WHY BE CONCERNED WITH Ai1"I'ECEDENT PRECIPITATION? Water levels in wetlands are influenced by the various components of the hydrologic budget, including precipitation.Because precipitation exerts such a strong control of the input side of the hydrologic budget, a variety of wetland assessments need information about the prior precipitation inputs influencing water levels observed on a site.The Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1997)advises that 'because seasonal conditions and recent weather conditions can contribute to surface water being present on a nonwetland site,both should be considered wben applying this indicator"[visual observation of inundation](para.49.b(l)),and "[w]hen applying this indicator[visual observation of sod saturation],both the season of the year and preceding weather conditions must be considered"(para.49.b(2)). 1.2 WIiAT IS "NORMAL"PRECIPITATION? "Normal"has two different meanings when used to describe precipitation.One is a single-value estimate of the mean and the other is a range of precipitation amounts. 1.2.1 "Normal Precipitation"as a Single Value The National Climatic Data Center(NCDC 1995) defines"normal"as the"anthmetrc mean of a climatological element computed over three consecutive decades."Therefore,normal precipitation is the average of the precipitation amounts for the period of interest,for instance,for a particular month. For example,using this definition,normal April precipitation in Grand Island,NE,is 2.50 inches,because that is the average amount of ram that fell in all Aprils evaluated at that recording station during the previous three decades.Any April precipitation amounts greater than or less than 2.50 inches in Grand Island would be reported as deviations from normal for that month.Although this definition is useful for maintaining climatological records,it has little utility for classifying meteoric inputs into broad classes such as"normal,""below normal,"or"above normal."For that purpose,the concept of a"range of normal"precipitation amounts is more appropriate. 1.2.2"Ranges of Normal Precipitation" The concept of a"range of normal precipitation"is useful for grouping precipitation inputs into broad classes.The boundaries of these classes depend on the number of classes desired,the purpose of the classification,and tradition in the discipline. The NCDC' computes several different probability ranges for different purposes,including quintiles(0-20°i percentile,200'- 40"percentile,etc),deciies(0-10'"percentile, 10"-20'h percentile,etc.),and others oriented toward extreme events. Some meteorologists prefer to assign the label of"normal"to the middle two quartiles (25'h to 75°'percentiles of probability).Various frequency analyses use slightly different cutoff thresholds for their middle range of precipitation frequencies (Table 1) The Standardized Precipitation Index(SPI)has the widest range of normal,but intermediate percentiles are also available at their Web site.The 30"'to 70'h percentile thresholds are used in this report as the range of normal because those are the ones used in the only analysis that was specifically designed for wetland regulation(Food Security Act). The user of this report,however,should recognize that local climatologists may prefer slightly different ranges of normal.The technical definition of the WETS Tables range of normal can be found in Appendix D. For convenience,abbreviations are listed in the Notation(Appendix E). 1 Table 1. Upper and Lower Percentile Thresholds for Middle Ranges of Precipitation Models. Model Lower Threshold Upper Threshold USDA National Water and Climate 3&percentile 70"percentile Center WETS Tables National Climate Data Center Palmer 2EP percentile 72n4 percentile drought indices National Drought Mitigation Center 160 percentiles 84b percentile' Standardized Precipitation Index US Geological Survey Stream Gauge 25"percentile 740 percentile ' analyses ' The values of 26 and 74 found at the National Drought Center Web site are wrong(M Svoboda,NDMC,personal communication,July 1999). 1.2.3 The Three-Decade Base Period Many climatological probabilities,including the USDA WETS Tables discussed below,are calculated on the basis of the most recent three decades of data.The current base period is 1961-1990.On January 1,2001,the new base period for calculations will become 1971- 2000.The reasons for choosing the most recent three decades are both statistical and historical(Kunkel and Court 1990).For example, comparisons between different recording stations need to be made for the same time period;climatic change may alter probabilities of occurrence over the decades;recording technologies have been upgraded around the Nation at roughly comparable times; etc. Longer records are available at many weather stations, and these longer records are useful for calculating extreme events, such as 100-year floods,but the range of most likely precipitation is currently calculated on the basis of the most recent three decades of record 2 2. RANGE OF NORMAL FROM THE "WETS Tables" A WETS Table (Figure 1)is a statistical summary of monthly precipitation and temperature for any of the 8000+reporting stations of the National Weather Service(NWS)Cooperative Network.The Tables are available for free on the Internet and from District Offices of the Natural Resources Conservation Service(MRCS).They present the ranges of normal precipitation,growing season dates as recommended for wetlands regulation,and monthly and annual precipitation totals for the period of record of each NWS reporting station. 2.1. ACCESSING THE WETS TABLES The Internet address for the WETS Tables is: httn-//www.wee.nres.usda eov/water/wetlands.html The sequence of menu selections from this Web site is: 1." Select desired region"; "Go to county selection" 2. "Select desired county";"Go to FTP download" 3. "Select this line to receive the information for county from our FTP site' I The WETS Table for a particular county may include tables for several weather stations in that a county,so one may have to scroll through a series of tables to find the desired locations.These can be saved to a computer word-processing fife by cut-and-paste techniques.For word processing they format best as Couner 10-point text with 0.5-inch margins. 2.2 IMPORTANT INFORMATION ON THE WETS TABLES(FIGURE 1) Key elements of a WETS Table are • Station location(name, latitude,longitude,and elevation) e.g.,Grand Island WSO AP,NE,4058 Is%098191ong, 1840 ft elev. • "Starting year"and"ending year"tell the time period used to calculate ranges of normal and means e.g, 1961 to 1990 • Temperature averages are arithmetic means of the monthly records e.g.,mean April temperature is 50.8°F • Precipitation data i)monthly average(arithmetic mean) e g.,mean April precipitation is 2.50 inches ii)range of normal(30%chance will have"less than"and"more than') e.g.,normal April rainfall is between 1.37 inches and 3.05 inches • Growing season dates e.g.,April 15 to October 16,for 50%likelihood of last and first 28•F frost • Page(Sheet)2 of the output shows monthly precipitation totals for the long-term record for the station. 3 WETS station : GRAND ISLAND W80 AP, NE3395 CREATION DATE: 6/24(96 Latitude: 4058 Longitudes 09819 Elevation: IS40 State FIps/county(FIPS) : 31079 County Name: Hall Start yr. - 1961 End yr. - 1990 ------------------------------------------------------------------------ Temperature Precipitation (Degrees F.) (Inches) 30% chance avg will have 0 of avg ------- ------- ----'-- ----------------- days total Month avg avg avg avg lens more w/.l snow daily daily than than or fall max min I more ----------------------------------------------------------------------- January 32.7 11.1 21.9 0.46 0.26 0.60 1 4.9 February 38.1 26.4 27.3 0.73 0.33 0.88 1 6.4 March 49.2 26.3 37.8 1.89 0.69 2.28 3 6.5 April 63.4 38.2 50.8 2.50 1.37 3.05 4 1.4 May 73.3 49.4 61.4 3.82 2.51 4.59 6 0.1 June 84.0 59.1 71.6 3.91 2.20 4.76 5 0.0 July 88.8 64.7 76.8 2.83 1.89 3.39 5 0.0 August 06.4 62.0 74.2 2.87 1.82 3.46 5 0.0 September 76.6 51.6 64.1 2.95 1.36 3.49 4 0.1 October 65.8 39.2 52.5 1.35 0.49 1.63 2 0.5 November 49.2 26.2 37.7 1.04 0.35 1.25 2 3.8 December 35.8 14.9 25.3 0.71 0.34 0.87 2 7.5 ^-------- ------- ------- ------- -------- -------- -------- ---- ------ ------- ------ - ------ -------- ------ - --- ------ Annual ----- ----- ----- ------ 21.31 27.70 -- ---- Average 61.9 38.3 50.1 ---- ------ ------ ---- -- - - -^ ---- ------- - ------ -------- -------- ---^ ------ Total ----- ----- ----- 24.97 ------ ------ 40 31.3 GROWING SEASON DATES ---------------- Temperature Probability -24 F or higher 28 F or higher 32 F or higher --------------------- -----------------I-----------------I---------------- Beginning and Ending Dates Growing Season Length 50 percent * 4/ 7 to 10/25 4/15 to 10/16 4/26 to ID/ 6 202 days 194 days 264 days 70 percent * 4/ 3 to 10/29 4/11 to 10/20 4/21 to 10/11 209 days 192 days 172 days ------------------------------- * Percent chance of the growing season occurring between the Beginning and Ending dates. total 1903-1996 prep Figure 1. WETS table for Grand Island,NE (NWC 1996) (Continued) 4 I Station % M3395, GYMD ISLAND 'KS0 AP ------- Unit - inches yr - mar say JunJul au slop Oct nov doe annl -- --- --- --- -i-- --_- - (data from 1903 to 1960 omitted to save space) 61 0.00 D.49 1.53 1.79 H7.49 M4.01 4.76 1.33 2.S5 0.20 D.B6 1.03 26.04 62 0.13 1.64 Ml.S8 0.52 3.43 2.75 8.78 1.65 1.59 1.35 0.11 0.68 24.21 63 0.70 0.21 1.17 1.39 3.28 3.22 2.18 3.06 3.45 0.06 0.25 MO.14 19.11 64 0.07 0.92 1.65 4.0 0.43 4.50 3.00 3.44 1.27 0.13 0.14 0.16 20.68 65 0.67 M1.23 1.26 2.18 5.97 5.21 2.36 3.35 9.00 0.37 0.50 0.53 32.63 66 0.23 MO.78 0.58 1.20 1.03 2.98 3.47 1.68 0.43 0.66 0.09 0.67 13.79 67 0,59 0.07 0.01 6.99 3.40 13.96 0.98 1.30 1.02 1.37 0.22 0.46 24.37 68 0.13 0.32 0.39 3.47 2.23 7.13 4.82 4.41 2.33 3.61 0.61 2.17 31.62 69MO.91 2.48A 0.19 2.55 4.13 3.46 3.10 3.75 2.01 3.43 0.19 0.82 27.02 70MO.04 0.24 0.42 2.72 2.49 0.81 0.63 3.36 5.76 1.44 0.33 0.07 18.31 71240.82 3.39 1.12 0.95 5.32 5.62 2.27 0.66 2.35 1.75 1.82 0.50 25.57 72M0.19 0.17 0.23 3.00 5.91 1.86 4.98 1.43 2.50 1.04 2.41 M2.04 25.76 73 0.77 0.45 5.57 1.63 3.85 0.84 2.90 1.38 8.39 1.51 2.37 2.07 31..73 74 0.62 MO.07 D.SI 1.73 2.44 2.67 1.35 0.50 1.41 0.25 1.34 12.89 75M0.86 M0.46 1.02 2.76 1.50 6.86 2.35 1.18 1.01 0.11 3.26 0.16 21.53 76 0.39 0.73 2.15 2.79 3.21 2.11 1.12 0.78 2.42 0.07 0.12 0.04 15.93 77 0.42 0.18 3.30 4.89 6.85 1.37 1.73 8.73 7.77 1.42 1.13 0.43 36.22 78M0.27 M1.18 0.83 6.12 1.87 0.50 2.8B 3.05 1.62 0.56 1.36 M0.64 2D.88 79MOA3 MO.43 5.56 3.27 3.99 2.65 2.66 1.39 2.54 3.02 1.78 0.48 28.60 BOM0.80 0.65 2.23 1.92 2.06 3.62 0.85 4.42 0.83 1.46 0.12 0.18 19.14 81 0.16 0.19 3.14 1.14 4.28 0.60 3.45 4.39 0.93 1.08 3.21 0.63 23.19 82 0.65 0.56 2.41 3.25 8.88 4.47 2.65 5.78 2.37 2.06 1.49 1.18 35.65 83 0.67 0.35 3.41 1.30 4.S9 6.29 1.71 2.04 2.67 1.08 3.77 0.78 28.66 84 0.24 1.65 3.18 7.34 5.75 3.95 1.99 1.21 0.19 3.49 1.37 1.34 31.70 85 0.27 0.27 1.15 4.37 4.62 3.98 3.20 2.25 5.80 1.83 0.61 0.27 28.62 86 0.00 0.50 1.98 2.52 3.OS 3.07 3.77 2.51 3.65 1.31 0.23 0.31 24.90 87MD.06 0.72 6.63 1.37 4.86 1.34 1.32 5.41 1.19 0.79 1.19 0.81 23.69 BBM1.13 0.33 0.11 2.41 1.77 4.39 3.93 2.79 3.26 0.01 0.70 0.27 21.10 89 0.71 M0.64 0.41 0.09 1.90 4.86 2.20 3.26 6.49 0.94 0.03 MO.41 21.94 90 0.37 0.45 3.00 0.46 4.25 8.22 3.64 3.16 0.72 0.90 0.82 0.76 26.64 91 0.52 0.06 1.79 2.73 6.27 5.25 5.74 1.34 0.79 2.61 1.71 2.11 29.92 Notes: Data missing in any month have a W flag Data missing for all days in a month is blank Figure 1. (Concluded) 2.3 INTERPRETING"ZERO"PRECIPITATION LEVELS IN THE WETS TABLES The WETS Tables report missing precipitation data in two ways,either with an%P beside the monthly value(for example, "M1.25"),or with a blank for the month. An"M"is used if one or more days of data have been recorded as"missing." A blank monthly total is shown if no data are available for that month. "0 00"is entered for a month that has a full record of data but in which no precipitation fell. 2.4 GRAPHICAL PRESENTATION OF THE INFORMATION ON WETS TABLES Changes in monthly precipitation data and their deviation with respect to range of normal are often more understandable when presented in a graphic format,such as Figure 2.This graph shows monthly precipitation totals for a particular year,the range of normal precipitation for each calendar 5 17 7 WETS Table ® { 6 Data Grand 6 Island,NE 0 5 1991 ® •Prectptta ton 6 m Totals for 4 'EL 4 1991 a` 3 High Normal 9 � 2 ® ® 2 Low 1 \ Normal m ® 1 c a M i+ C T e. > v � U- M Q. 2 -3 -A Q to O Z a }--Growing Season -I Figure 2. Graphic presentation of WETS Table information plus monthly precipitation totals for a particular year. This presentation format allows rapid assessment of rainfall conditions for the period of interest. See text for further discussion month based on the preceding three decades,and the duration of the growing season It is easy to plot the range of normal precipitation(shaded area in Figure 2)for the weather stations that are within the area of responsibility of the field office.These can then serve as templates,be photocopied,and be used to plot monthly totals on a case-by-case basis. Plotting of WETS Table and monthly total precipitation data in a standard format reduces ambiguities when evaluating precipitation conditions during the period of concern. 6 3 FINDING RECENT PRECIPITATION DATA 3.1 EXISTING SOURCES As of this writing,finding recent precipitation data is the most cumbersome part of determining whether precipitation was normal during the two or three months prior to a site visit. There currently is a several month delay between the date of collection and final release of data to the public by the National Oceanic and Atmospheric Administration(NOAA) The delay results from quality-control protocols used by the NCDC. Raw data are usually very similar to those finally published,but data should undergo NCDC quality control steps before being used for legal purposes. All data published in the Climatologic Data Summaries and in the WETS Tables have undergone this process. Excellent sources of recent data are the Regional Climate Centers(RCC)and the state climatologists. • Regional Climate Centers: httn://met-www.cit.cornell.edu/otheT rcc.htrnl • State Climatologists: htto://www ncdc.noaa.gov/ol/ciimate/aasc,html These offices may be able to provide data from stations that are not part of the WETS network as well as raw data from official recording stations Recent precipitation information may also be available from unofficial sources outside of the NWS network,such as newspapers,research sites,etc. Caution should be used with data from non-NWS sources,as turbulence at improperly located instruments, equipment used,and data transcription are all potential sources of error that may not be monitored as closely as done by the NCDC. To determine their reliability,unofficial data should be correlated with long-term data from surrounding official weather stations using procedures described in Section 3.3. A great nu tuber of Internet Web sites claim to provide recent weather data Users of climatic data are encouraged to explore city,state,and university Web sites for locally useful information that may be accessed on a contirraing basis. On a national basis,the Climate Prediction Center publishes weekly and monthly precipitation data for approximately 225 cities around the Nation at http://www.ci)c.ncei).noaa.goy/products/analysis monitorin¢(cdus/vrcr) temp tables/ The US Geological Survey(USGS)publishes precipitation data from various ram gauges around the Nation.This information is published on a state-by-state basis.The national index for the Web site is found at- bttp-//water.usgs.gov/Tealtime.htmI 3.2 UNWIED CLIMATE ACCESS NETWORK(UCAN)2 The NRCS,six RCC's (NOAA),and NCDC(NOAA)are currently designing and constructing the Unified Climate Access Network(UCAN). UCAN is a consortium of Federal and state agencies whose focus is to unify access and availability of climate data and information for natural resource management UCAN will allow user access to quahty-controlled climate information more quickly, easily,and efficiently than previously possible. 2 Contributed by?.Pastens,National Water and Climate Center,Portland,OR. 7 This Internet-based climate system will provide access to climate information as current as a month old for 8000+climate stations and historical data from over 25,000 stations collected by Federal, state,and county networks located throughout the U.S As of October 1998 a prototype UCAN demonstration Web site has been established at the following Uniform Resource Location(URL)- hUp://www.sme.Isu.edu/ucan.negUCAN.btml A major goal of this project is to enable climate information users to obtain information from a UCAN Web page. The UCAN system will automatically send requests for specific data sets and climate products to a network of regional and national climate center computer systems that maintain the data archive for the requested product. In addition to access to multiple data sets and output formats,users M11 be able to run a variety of climatic data analysis programs.These include statistical averages,frequency analyses, spatial mapping, risk analyses, and modeling applications that require specialized climatic information 3.3 USING ONSITE RAIN GAUGES It is a common practice on research projects to collect precipitation data on or near an investigation site in order to record differences between rainfall onsite and that recorded at the nearest NWS station.This is done because rainfall can vary considerably over short distances,particularly in locations and seasons where meteorology is dominated by convective thunderstorms When using onsite rain gauges,however,caution is required for several reasons: • The previous three-decade precipitation record is usually not available at project sites,so one must compare onsite data with official NWS data from nearby stations to determine whether onsite precipitation was outside the range of normal. • Onsite precipitation data seldom undergo the same quality-control procedures as those applied to the NWS database. • Onsmte rain gauges may be unreliable due to poor quality,improper installation,or infrequent readings. 3.3.1.Rain Gauge Quality and Location Of the above-mentioned problems,the easiest to address is quality of the ram gauge.Automatic, recording rain gauges are available from numerous scientific and environmental supply houses Most of these meet the minimum standards specified for Cooperative Weather Station observations(NWS 1989; section on rain gauges reproduced herein in Appendix B). Whatever fain gauge is chosen,it should be read daily because it is necessary to compare onsite and nearby NWS data for daily differences in order to interpret the source of discrepancies. Gauge quality and installation should be reported in studies using unofficial data;a sample form for such reporting is included in Appendix C. Because wind turbulence varies with shelter and topographic setting(Smith 1993), a rain gauge should be located with care.The NWS recommends that Gages should not be located close to isolated obstructions such as trees and buildings,which may deflect precipitation due to erratic turbulence. Gages should not be located in wide-open spaces or on elevated sites,such as tops of buildings,because of wind and the resulting turbulence problems. The best location is where the gage is uniformly protected in all directions, such as in an opening 8 i in a grove of trees. The height of the protection should not exceed twice its distance from the gage. As a general rule,the windier the gage location is,the greater the precipitation error will be. (NWS 1989,p. 6) This advice is essentially the same as the more recent recommendations by the World Meteorological Organization(1996)and the US Environmental Protection Agency(Finkelstein et al. 1983).Advice regarding installation in forests has not been located,but a knowledge of rainfall interception by forest canopies suggests that rain gauges should not be located under trees,because precipitation interception will vary with canopy closure and age and with storm intensity and duration (Smith 1993). 3.3.2Interpreting Onsite Precipitation Data In order to check the accuracy of records from unofficial min gauges it is necessary to plot daily precipitation data from both the unofficial and nearby official weather stations on the same graph (Figure 3).If practicable,several official weather stations should be used, even if they are located fairly far apart This way it can be determined how much rainfall vanes in the geographic region and whether the unofficial rain gauge varies by comparable amounts.Topographic variability between stations should be taken into account when comparing one station with another.Generally,rain gauges closer to one another report more similar records than those further apart Using this method,anomalies in the unofficial record should be obvious. Figure 3 shows such a plot for an unofficial rain gauge in southeast Indiana(Wetland Research Site,black bars)and for three official sites within 20 miles of the research site A year's worth of data is presented.Note the variability among official weather stations,for example,in the first week in January. All stations had over an inch of precipitation on the 4 s and 5'"of January,but the precipitation fell over two days at North Vernon and Seymore and fell in one day at Scottsburg. On February 16 and 17 the research station reported two precipitation events,one as snow and one as rainfall;temperatures on both days remained below freezing.Only one event was reported at the official stations.A subsequent telephone call to the operator showed that the second record was a con- version to wet precipitation amounts;the erroneous entry was left in Figure 3 to illustrate such problems with raw data.Two lessons can be learned here- (1)Raw field data are bound to have inconsistencies and need to be scrutinized before final publication This is why the NWS submits all data to quahty-control procedures.(2)Temporarily installed rain gauges bought from environmental supply houses are often unheated and therefore do not record snowfall accurately,as was the case with this unofficial rain gauge, too There seem to be no inconsistencies in the March records.The lone precipitation record at North Vernon on the 31'was probably part of the same system that delivered precipitation at all four stations on April 10 One wonders whether precipitation on April 10-12 was accurately reported;temporal distribu- tions would have been more consistent had the April 12 rainfall at the research site occurred on the same day as the three official stations.Rainfall on May 13,July 2,and November 15 was higher at the research site than at the official stations,but not so high as to seriously question the accuracy of the readings without statistical analyses of variance for the entire period of record.. Such informal comparisons of readmgs at the unofficial and official sites indicate that precipita- tion fell at all four stations in the same patterns.Therefore,antecedent precipitation at the research site could be evaluated using analyses from the surrounding official weather stations,as in Figure 4. 9 I 2 January,1993 0 c ,�0 1 c_ Z. 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24.25 28 27 28 29 30 31 2 February,1989 s u e 1 21. LWO., Iwo llml4g 10 1 2 3 4 5 6 7 9 9 10 11 12 13 14 15 1617 18 19 20 21 22 23 24 25 26 27 28 C I t2 March,1993 o c c A T R 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425282728293031 0 2 April,1993 IL 11 Kill V C 1 C m K T r t 131 2 3 4 6 6 7 8 9 10 11 12 13 14 15 15 1718 19 20 21 22 23 24 25 26 27 28 29 30 I Wetland Research Site,Jackson and Jennings Counties,IN I Seymour NWS station,Jackson County,IN INDIANA North Vernon NWS Stallon,Jennings County,IN ; Scoasburg NWS Station,Scott County,IN mouNyy, r Seyr v^�I 1Reeeem,S� i Site f y t• Scotlm ,; . Figure 3. Example of comparison of data from unofficial weather station (black bars;Jenkinson and Franzmeier 1996)and from surrounding official NWS weather stations(gray bars; NOAA 1994) The data from the unofficial station are plotted from uncorrected field sheets(Jenkinson, personal communication, 1998). Note variability between NWS sites. Precipitatlon amounts recorded at the unofficial site were similar to those reported at the NWS stations and could therefore be accepted as reasonably accurate (Sheet 1 of 3) 10 Z 2 May, 1993 Ram M" 2A OE_-MAU c e A G 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 1617 18 19 20 21 22 23 24 25 26 27 2B 29 30 31 2 June,1993 c J° 1 C G 1 2 9 4 5 8 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 s 2 4.47 July,1993 u c tY a C 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 25 26 27 28 22 30 31 2.52 317 T Z August 1993 Ing 1 C: A 2' C 1 2 3 4 5 6 7 8 9 10 11 1213 14 15 1617 18 18 20 21 22 23 24 25 26 27 28 29 30 q31 Welland Research Site,Jackson and Jennings Counties,IN Seymour NWS Station,Jackson County,IN North Vernon NWS Sta9on,Jennings County,IN ScottatwrgNWS Station,Scott County.IN Figure 3. (Sheet 2 of 3) 11 m Z September,1993 10 A- III c C C ffd -I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1617 18 19 20 21 22 23 2A 25 26 27 2129 30 2 October,1993 c � 1 c R 0: a ; C 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 <A8 3.1 6 252 2 November,1993 s u c p 1 c A X m O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1617 18 19 20 21 22 23 24 25 26 27 28 29 30 d 2 December,1993 r u c c >Y _>1 io S t ° O i 2 3 4 S 6 7 8 9 10 11 12 13 14 15 161718 19 20 21 22 23 24 25 26 27 28 29 30 31 Wetland Research Site,Jackson and Jennings Counties,IN Seymour NWS Station,Jackson County,IN North Vernon NWS Station,Jennings County,IN Scottsburg NWS Station,Scott County,IN Figure 3. (Sheet 3 of 3) 12 I 6 A h 6 5 � 5 To ' ew � e d ( Comparison of Ranges 1 of Normal Precipitation c .n " 7+ c 1 75 trn 0. > o EV ti � ¢ 2 n Q ( O Z a North Vernon, IN Seymour, IN Scottsburg, IN �•�'� Research Station y7 B ! — 7 = 6 6 t 0 c.. Na 3 3 u � z a 1 Comparison of Monthly 1 Total Precipitation - 1993 u Q ce � m 0 a m � � Q Cn Z A Growing Season --{ INDtjNAI! WETS Table Exam Range of Normal Seymo Precipitation: \ Seymour, !N \ResearchSiteScottsbu Figure 4. A. Ranges of normal for monthly precipitation at three NWS stations in Indiana(NWCC 1996) H. Actual monthly precipitation totals at three NWS stations and a research station in Indiana, superimposed on a graph of average range of normal monthly precipitation at the NWS stations (gray) I3 I Figure 4A shows the monthly ranges of normal for the three NWS stations.Because differences between { ranges of normal were so small, it is acceptable to use any of these ranges of normal to evaluate precipitation data at the research site.As a general policy,ranges of normal at nearby stations should be compared to assure that elevation and physiography are not producing systematic differences between weather stations. 1 Comparison of onsite and offsite data(Figure 413)indicates that precipitation was within the range of normal in February,March,May,June,July, October, and December.In this case these same conclusions would have been reached without the onsite data,but with less confidence.One can envision situations where several nearby NWS stations have similar precipitation amounts that straddle the boundary between normal and above normal; for example,if April precipitation had been slightly less at all stations in Figure 4B.Onsite data are helpful in such cases where data from official stations fall on either side of a boundary of normal. 3.33.Summary of Use of Onsite Rain Gauges 1. Onsite rain gauges can identify onsite precipitation events that differ significantly from those recorded at nearby NWS stations. 2. Onsite ram gauges should meet minimum quality standards described in NWS Observing Handbook No.2(NWS 1989)(pertinent section reproduced in Appendix B). 3. Onsite rain gauges should be installed in somewhat sheltered areas,but the distance from sheltering trees or buildings should be at least twice the height of the trees or buildings. 4. Onsite rain gauges should be read daily,and for a long enough monitoring period to develop a record that can be confidently compared with records from nearby NWS stations. 5. Data from onsite ram gauges need to be compared with data from several nearby NWS stations to check for deviations from regional patterns.Such comparisons can be easily performed by plotting daily data(onsite and NWS)on the same chronological graph, 6. Discrepancies between temporal patterns of onsite and NWS data need to be explained.If unofficial data track the official data for most storm events,then the data can probably be trusted, and an anomalous ramfill record at one site probably reflects genume geographic variability. However,if the data at the official stations track together and the data from the unofficial site do not,then the unofficial data set should be evaluated for errors. Numerous differences would call into question the data from the onsite rain gauge. 14 4. EVALUATING ANTECEDENT PRECIPITATION CONDITIONS AT A SITE This section presents three alternate procedures to evaluate whether precipitation prior to a particular date was within the range of normal for a particular reporting station. The first and simplest method utilizes monthly precipitation data and the WETS Tables,and is taken from the NRCS Engineering Field Handbook(MRCS 1997). The second method evaluates daily precipitation data on the basis of 30-day rolling sums. The third method combines the two procedures 4.1 NRCS ENGINEERING FILED HANDBOOK 4.1.1. Background The NRCS Engineering Field Handbook(MRCS 1997;hereafter"the NRCS method"J presents a procedure to systematically evaluate rainfall conditions for the three-month period prior to the site investigation.The method is summarized below;the complete procedure can be found on pages 24-26 of "Hydrology Tools for Wetland Determination,"which can be downloaded as a.pdf file at htto//www.wcc.ures.usda.eov/water/ouality/text/hydrolog.html. I The methodology calculates a numerical rating of prior precipitation by weighting the data for both(1)amount of precipitation,and(2)relative age of a rainfall event (Warne and Woodward 1998; Woodward et al. 1996). These two weighting factors("departure from normal'and"recentness") are multiplied to give a numerical rating that is used to decide whether the prior precipitation for the entire 3-month period was within the range of normal or not.The procedure is as follows: 4.1.2. NRCS Method for Estimating Antecedent Moisture Conditions at a Site. Using the NRCS rainfall documentation sheet(Figure 5;values entered for an example from Grand Island,NE). a.Fill out the background information(Weather Station and Growing Season from WETS Table, Figure 1)."Photo date"is the date of a hydrologic observation. b.Fill in the"Month"column.Usually the"I"prior month"is the month of the hydrologic observation. When hydrologic observations were made early in a calendar month, the"la prior month"might be evaluated better as the preceding calendar month.The entire month's worth of rainfall is entered in this column because this method assumes that only monthly totals of precipitation are available. c.Fill in the columns"3 yrs.in 10 less than"and"3 yrs. in 10 more than."using information from the station's WETS table(Figure 1). d.In column`rainfall'enter the actual rainfall tbat fell in months listed in the"Month"column. e.Compare the actual rainfall amounts for each month with the ranges of normal you entered in the columns of long-term rainfall records.In the column"Condition dry,wet,normal"enter"dry," "wet,"or"normal,"depending on the comparison between actual rainfall and long-term ranges of normal. 15 f.In the column"Condition value,"enter the appropriate"condition value"from the small table immediately below.For example,if the actual rainfall was wetter than normal, then enter condition value"3." g, Multiply the'condition value"by the"Month weight factor"to obtain the value to enter into the column"Product of previous two columns." h.Add the three products in the last column to obtain the"sum"at the bottom of that column.The sum should be a whole number between 6 and 18. i. Conclude whether the prior period was drier than normal,normal,or wetter than normal by comparing the calculated sum to the small look-up table in the Note below the fast three columns of Figure 5. 4.1.3. Comments on the NRCS Method. The NRCS method has the advantages of considering data from the previous three months rather than lust one,of weighting those data for length of time since the precipitation contributed to the water budget,of using easily accessible information,and of being simple to apply.It has obvious wealmesses, the most important being the assumption that rainfall was evenly distributed during the month of observation.Nevertheless,the method is a significant improvement on the situation of ignoring antecedent precipitation inputs into site hydrology. Some of the assumptions one must be aware of when using the method are. • that rain was evenly distributed for the month of observation. The importance of this assumption is magnified by the fact that the"recency"weighting factor is largest for the month of observation. • tbat three months is the proper length of time to evaluate antecedent precipitation. Evapotranspiration becomes more intense during the muddle of the growing season and therefore surface and near surface residence times may be much less than three months.Furthermore, antecedent precipitation typically influences flooded,open system wetlands differently than closed depressions or in seeps. that snowmelt contributes to wetland hydrology the same as rainfall 4.2 METHOD OF ROLLING TOTALS 4.2.1 Background The NRCS Engineering Field Handbook compares actual precipitation with monthly ranges of normal by accessing published monthly rainfall summaries from NOAA and National Water and Climate Center(NWCC). Precipitation patterns within a particular month are not reflected in monthly totals. Because the penod of continuous muadation required for wetland hydrology is less than a month,it is commonly desirable and necessary to utilize and evaluate higher frequency(daily)precipitation data.The 30-day rolling total is technically more sound than monthly totals in that monthly totals are reset to zero at the beginning of each month and therefore may not accurately reflect antecedent rainfall in the middle of the month. The 30-day rolling total is generated by summing the past 30 days'precipitation.By continually updating a tally of the prior 30-day rainfall totals,one can plot a record of rainfall for the immediately preceding 30 days of rain on a daily basis(for example,Figure 6).Overlaying a plot of range of normal 16 Chapter 19 Hydrology Tools for Pert 850 Wetlaad Daterminattan Rnglnearina Field Handueok Figure 19-7 Rainfall documentation wor"heet Aaia fi&Dacumentatkm (use with photographs) weatharstatlorraaci� t„SSDLandowner. 37 ,firutom, Tract no.: 'I 7- County AO)I stem ME Sol] name. alpi n-4--xL Growingsessoo: ,5� - 1pl aL Photo dafP. 7�t Long-term raloraD records 3yra In 3yra.in Conditiorr Condition Month Product of 10. 0 lU more Rain dry,wet value weight pnwbw two Month than Nomul than halt normal value columns letpriormanth• a.5 11. 7 + 3 3 2ndpriormonth` aal ktirptAta 2 3rd prior month* MW I Compared to photo date Sum 1 s Nooe:If sum is Condition value: 6-9 then prior period has been Dry .1 drierthannormal Norow .2 10.14 than prior period has been Wet .3 normal •1g an prior period has been weGEr t11Hi1 n e nal Coackulln115' Qn�ecec n 'au ODS LJ��� �� Cnrr�z o C' nor mn ti Figure 5. Worksheet to determine whether precipitation was within the range of normal prior to a site visit,taken from the NRCS Engineering Field Handbook, Chapter 19 (NRCS 1997) I7 1 o Grand Island, NE Q s 1991 Precipitation l 9 �- Totals for 1991 o g 30-Day 8 Rolling Range of Normal 7 Total v 7 Precipitation ti 6 Daily 6 Preci .R 5 I Totals station 5 4 4 0 3 3 2 2 c m Ui Q Q W O Z 0 �--- Growing Season ---� Figure 6. 30-day rolling totals of precipitation at Grand Island, NE,overlaid on graph of daily precipitation and monthly precipitation, with range of normal in gray precipitation on such a daily plot allows the delineator to evaluate whether antecedent precipitation was greater or less than normal throughout a month rather than just at the beginning or end. 4.2.2.Procedure of 30-day Rolling Totals The procedure of 30-day rolling totals consists of three parts: 1.Calculating and plotting 30-day rolling totals for the time period of interest(Figure 6 and Table 2). 2.Overlaying a plot of monthly ranges of normal on the plot of 30-day rolling totals(Fgure 6). 3 Comparing the rolling 30-day sutras to the monthly ranges of normal to determine whether antecedent precipitation was within the range of normal. Preparing a plot of 30-day rolling totals and monthly ranges of normal(Figure 6) The graphics needed for the method of 30-day running totals are prepared as follows.Continuing with the Grand Island example,Table 2 shows the 30-day rolling total calculated for February through May 1991. 18 i Table 2. Daily Precipitation and 30-day Rolling Totals for Jan-May 1991 at Grand Island, NE NOAA 1992). Dally 30-day Dally 30-day Dally 30-day Date proolp Rolling Total Date Precip Rollin Total Date Precl Rollin Total 1-Jan 15-Feb 027 1-Apr 0.D6 1.53 2-Jan 16-Feb 0.27 2-Apr 153 3-Jan 17-Feb 035 032 3-Apr 1.63 4-Jan D 05 1 B-Feb 001 033 4-Apr 1.53 5-Jan D 15 19-Feb 033 5-Apr 153 B-Jan 20-Feb 0.33 6-Apr 153 7-Jan 21-Feb 0.33 7-Apr 153 8-Jan 22-Feb 03 1 B-Apr 153 9Jan 23-Feb 023 9-Apr 1 53 10-Jan 005 24-Feb 013 IC-Apr 1.53 11Jan 25-Feb 013 11-Apr 043 1.75 12-Jan 26-Feb 013 12-Apr 017 183 13-Jan 27-Feb 0 13 13-Apr 0.17 2 14-Jen 28-Feb 006 14-Apr 1 94 15Jan 1-Mar 032 0.38 15-Apr 194 16-Jan 2-Mer 038 16-Apr 1 79 17-Jan 3-Mar 038 17-Apr 0 OB 1 B7 18-}an 4-Mar 0.38 18-Apr 0.01 177 19-Jan 5-Mer 0.38 19-Apr 0.21 1.93 20-Jen &Mar 0.38 20-Apr 1.84 21Jan 7-Mar 038 21-Apr 0.D6 173 22Jan 8-Mar 038 22-Apr 1.73 23Jan 003 9-Mar 038 23-Apr 1.73 24-Jan 0 07 10-Mar 0.38 24-Apr 173 25-Jan 01 11-Mar 0.38 25-Apr 1.7 28Jan 12-Mar 021 059 264kpr 1.19 27Jan 13-Mar 0.09 068 27-Apr 1 19 28-Jan 14-Mar 068 2B-Apr 0.88 1 2.05 29Jan D 07 15-Mar 006 074 29-Apr 0.68 273 30Jen 0.52 16-Mar 074 30-Apr 273 31Jan 052 17-Mar 0.15 0.89 1-May 267 1-Fab 052 18-Mar 089 2-May 04 307 2-Feb 0.52 19-Mar 0.11 0.95 3-May 0.18 325 3-Fab 047 20-Mar 0.05 0.99 4-May 024 349 4-Feb 032 21-Mer O.D9 108 5-May 3.49 5-Fab 0,32 22-Mar 0.17 1.25 6-May 349 6-Feb 032 23-Mar 125 7-May 009 358 7-Feb 0.32 24-Mar 125 8-May 358 8-Feb 032 25-Mar 1.25 9-May 3.58 9-Feb 027 26-Mar 0.03 128 10aday 358 10-Feb 027 27-Mar 051 179 11-May 315 II-Feb 027 28-Mar 179 12-May 298 W-Feb 027 29-Mar 1 1.79 13-May 281 13-Fab 027 30-Mar 1.79 14-May 2.81 14Feb 027 31-Mar, 1.47 15-May 2 B1 19 1.In a 3-column table, tally date and daily precipitation for the 120 days preceding a site observation(the three columns in Table 2 are wrapped to fit on the page). 2. Starting with the 30th day,total the precipitation amounts for that day and the preceding 29 days;enter the sum in the third column,"30-day Roiling Total." This tedious calculation can be automated in most personal computer spread sheet software programs by copying and pasting the first instance of the command into subsequent rows of the third column. In Microsoft Excel(Microsoft Corporation 1985- 1997) the command is"=sum(bl:b30)." 3. Plot Column 3 against Column 1 (30-day rolling total against time, as in Figure 6). 4. Superimpose the monthly ranges of normal from the appropriate WETS Table. Plot the ranges of normal for each month at the end of that particular month,rather than the beginning or middle,because the range of normal from the WETS Table is for the preceding days of the month(preceding 28/29,30,or 31 days). 5_Superimpose the daily rainfall data("spike graph's to provide details of the distribution of rainfall within the months of interest. 4.2.3.Determining Whether Tallied Precipitation Was Within Range of Normal Deviation from the range of normal precipitation is determined by use of the superimposed plots of 30-day rolling totals and ranges of normal precipitation for the period of interest(for example, Figure 6) Daily precipitation data should also be superimposed on such graphs in order to understand how the 30-day rolling totals evolved. Using this methodology it is seen that in 1991 at Grand Island,January,March, and April precipitation levels were largely withm the range of normal,and February precipitation was slightly below normal. The first half of May was within the range of normal until May 16 when a 1.35-inch rain caused the 30-day total to rise above the range of normal.Between May 23 and May 25,2.33 inches of rain fell at the weather station,which caused the 30-day rolling sum to rise significantly above normal, where it stayed for the rest of the summer,except for a short period in early July. Scanty rains in the last half of July initiated a drought that lasted well into the fall.November and December precipitation levels were above normal. 4.2.4. Comments on the Method of 30-day Rolling Totals The strength of the method of 30-day rolling totals can be seen by comparing it to the method of monthly totals used by the WETS Tables(Figures 1 and 6).The two methods agree that precipitation levels in January,March,and April were within the range of normal and that February was slightly drier than normal Note,however,that the monthly tallies of the WETS Tables indicate that May was significantly wetter than normal whereas the more detailed method of 30-day rolling totals detected that the heavy rains of the wet summer did not occur until the middle and, especially,the end of May.Detailed knowledge of rainfall distributions in early May could have been particularly important to wetland scientists because that is shortly after the beginning of the regulatory growing season when field decisions were likely to have been made.The method of 30-day rolling totals provides a more accurate assessment of antecedent moisture conditions at a site than do monthly averages,which artificially zero rainfall totals at the beginning of each month. 20 However,the method of rolling sums also artificially zeroes rainfall after 30 days.Note in Figure 6 that 30-day rolling precipitation totals were much above normal for most of July and early August,despite the fact that daily rainfall records show most of July was dry(spike graph at bottom of Figure 6).Furthermore,antecedent precipitation levels fell from much above normal to well below normal within a space of three days in early August. This is a direct consequence of the method of calculating a 30-day rolling sum.A large mput remains within the rolling sum for exactly 30 days,and then abruptly drops out of the rolling total.In loamy and finer textured soils,changes in water tables are unlikely to be so abrupt. The method of rolling totals is often used to track the influence of antecedent precipitation on water levels in monitoring wells.It is well suited for this purpose because each well reading can be compared to an updated tally of antecedent precipitation. 4.3 COMBINED METHOD OF 30-DAY ROLLING TOTALS AND NRCS ENGINEERING FIELD HANDBOOK WEIGHTING FACTORS. Combining the method of 30-day rolling totals with the NRCS Engineering Field Handbook method of weighting antecedent precipitation is appropriate where precipitation influences site hydrology for two or three months. 4.3.1 Procedure for Combining the Methods of 30-day Rolling Totals and NRCS Engineering Field Handbook Weighting Factors. 1.On the plot of 30-day rolling totals(Figure 7)mark off 30-day blocks starting backward from the date of interest.Continuing with the Grand Island example,if a wetland is delineated on May 15,the plot of 30-day rolling totals would be blocked off into 30-day blocks:April 16-May 15;March 17-April 15; and February 15 -March 16. 2.Decide whether the 30-day blocks reflect normal,drier than normal,or wetter than normal precipitation by comparing the 30-day rolling totals with the ranges of monthly normal. Some of these decisions will require professional judgment 3.Record your decisions for the 30-day blocks in the Rainfall Documentation Form in the column labeled "Condition dry,wet,normal" (Table 3) 4.Fill out the subsequent columns of the form as instructed for the Engineering Field Handbook method (Section 4.1.2). 43.2 Comments on the Combined Method The combined method rated the three-months'precipitation prior to May 15 as being normal whereas the NRCS Engineering Field Handbook method rated it as wetter than normal(Table 3). The difference is the ability to calculate 30-day increments starting on any date rather than only at the beginning of the calendar month.Frequent use of the combined method will show how difficult it is to decide whether a particular 30-day period of rolling totals falls on one side of a threshold of normal or on the other side For example,it would be a close call to decide whether the penod of April 24 to May 23, 1991,was within or above the range of normal. 21 10 Grand island, NE 10 9 1991 30-Day 0 Precipitation tion 9 Roiling Totals for 1991 c 8 chord Second F Total 8 or a days Oda days Range of 7 "/ l Normal 7 a Preoipltation a 6 Daily 6 5 I T��nation 5 4 4 L 0 3 3 _c 2 "MIM 2 >> 1 r 1 11 .Rilf c n >, c to a > 0 U. ¢ g - Q co O Z C3 �--- Growing Season ----� Figure 7. Three 30-day periods prior to May 15,superimposed on Figure 6 Table 3. Comparison of Engineering Field Handbook Method and Combined Method Grand Island, Hall County, NE, 1991 Engineering Field Handbook Method Month 30"'%dta Normal Ire Wle Relnfall Dry,Wet, Condition Weight Product of Normal Value Value Values mo May 251 4.59 627 Wet 3 3 9 2ntl mo April 137 3.05 273 Normal 2 2 4 e rip March 069 2.28 179 Normal 2 1 2 sum=15 wetter than normal Combined Method 1"mo 4116-15 See Fig 7 See Flg 7 See Fig 7 Normal 2 3 6 Zr°mo 3117- 415 See Flg 7 See Fig 7 See FIg 7 Nornaf 2 2 4 2J1 5- 3f0 mo 3118 See Fig 7 Sea FIg 7 See Fig 7 Dry 1 1 I sum=11 normal 22 a 4A GENERAL OBSERVATIONS ON ASSESSMENTS OF ANTECEDENT PRECIPITATION • The WETS Tables alone are quickest and probably sufficient to use when simple generalizations about long-term trends are all that is needed. • The method of the Engineering Field Handbook will perforce be used when daily precipitation data are not readily available. • The simple method of 30-day rolling totals is readily used with long sets of monitoring well data because of ease of plotting information These plots,when superimposed on a daily precipitation spike graph,provide a powerful tool for explaining water well fluctuations. • The combined method is useful for making decisions regarding individual dates of observation at a site. Whenever feasible,the monthly analyses should be interpreted using the daily data from which the monthly summaries were aggregated. • The methods of the WETS Tables and rolling totals should be used in conjunction with indices of longer term hydrologic input,such as the Palmer drought indices,the Standardized Precipitation Index,and/or USGS stream gauge analyses(Section 6 below).The longer term record(many months to a year)may show the presence of a prolonged drought,a couple of months of normal rain-fall in the middle of the drought may not raise water tables to levels typical outside of the drought. • The WETS Tables evaluate the range of normal precipitation in monthly increments.Antecedent precipitation probably does not affect wetland hydrology in monthly or 30-day increments. The Standard Precipitation Index and Palmer drought indices(Section 6)have more flexible periods of evaluation of antecedent conditions. • Antecedent precipitation is only one part of the water budget.The other parts of the water budget need to be considered when interpreting observed levels of ground or surface water. • The dictation of impact of antecedent precipitation typically varies with the seasons.In the early spring,when evapotranspiration(ET)is low,there is probably a longer duration impact of prior precipitation than later in the summer when ET is high. • The duration of influence of antecedent precipitation on wetland hydrology does not seem to have been studied.The NRCS hydrologists chose three months as a reasonable length of time to evaluate antecedent precipitation for Food Security Act programs.The National Drought h1itiga- tion Center(NDMC)reports a three-month calculation of their Standardized Precipitation Index at their Web page of drought estimates for the Nation(htip://enso unl.edu/monitor/current.html}. In default of site-specific information to the contrary,three months preceding a date of site monitoring seems to be a reasonable length of time to evaluate whether precipitation was within the range of normal. • There is no way to remove professional judgment in borderline situations. Remember that the limits of the range of normal(301°and 700 percentiles)are themselves professional judgments. Moreover,when antecedent precipitation levels are close to thresholds of normal,uncertainties about other parts of the water budget become a major consideration. 23 5. GROWING SEASON Guidance of 6 March 1992(Office of the Chief of Engineers,6 March 1992,pars.3.b.) allows determination of the regulatory growing season with reference to NRCS soil survey information. In 1992, the most current soil survey information was contained in soil survey reports,which may be more than a decade old.More current growing season information may be obtained from the MRCS WETS Tables at the bottom of the first page of the entry for each reporting station. For most of the Nation the wetland delineation growing season:s approximated by the last and first dates with a 50 percent likelihood of 28° F frost. In Wooster,OH,for example,the growing season is April 23 to October 21 (Figure 8). The soil survey report(Soil Conservation Service 1984)gives the growing season as April 23 to October 18.The dates differ by three days at the end of the growing season(October 18 vs October 21)because the 1984 information was based on different baseline data(1951-1978 vs 1961-1990) WETS Station : WOOSTER EXP STATION, OH9312 CREATION DATE: 6/24/96 Latitude: 4047 Longitude: 08155 Elevation: 1020 State FIPS/County(FIPS): 39169 County Name: Wayne Start yr. - 1961 End yr. - 1990 GROWING SEASON DATES Temperature --------------------- -------------------------------------------------- Probability--_- 24 F or higher 28 F or higher 32 F or higher ------ --------- ----------------- -----------------(--------------- Beginning and Ending Dates Growing season Length 50 percent * 4/11 to il/ 2 4/23 to 10/21 5/ 5 to 10/ 7 205 days 181 days 155 days 70 percent * 4/ 7 to ll/ 6 4/19 to 10/25 5/ 1 to 10/11 213 days 169 days 163 days ----------------------------------------------------------------------- * Percent chance of the growing season occurring between the Beginning and Ending date?n. Figure 8. Growing season information as presented in WETS Tables,for Wooster, OH(NWCC 1996) 24 6. DROUGHT ANALYSES ON THE INTERNET There are several Internet Web sites that complement the NWCC WETS Tables by(1)providing near-real time precipitation information and(2)providing long-term frequency analyses of regional patterns of drought and moisture excess.These Web sites are not substitutes for analyses of site-specific data using the WETS Tables because of trade-offs made to develop real-tune,regional assessments. However,one should utilize Web sites in order to get a sense of long-term climatic trends in the region. Three analyses are discussed here: (1)Palmer drought indices,(2)Standard Precipitation Index(SPI),and (3)USGS stream gauge data.The Palmer index is reported for the previous week and for previous months.The SPI is available for the previous month.USGS data are reported for the previous day,week, and month.All are reported as or can be converted to frequency probabilities. The Palmer analyses incorporate precipitation, evapotranspiration,and regional soil properties and the SPI analyzes precipitation alone.The USGS analyses complement the Palmer and SPI analyses because they come from independent sources of information(stream flows vs weather) The authors recommend that wetland scientists consult both the USGS Web site and one of the climate Web sites to assess near-real time drought conditions.Final decisions involving quantitative evaluations of hydrology should be postponed until site-specific precipitation data can be collected and compared with the WETS data. The NDMC provides maps of eight different indices or climatic conditions related to drought or moisture excess at http.//enso.unl.edu/monitor/current html.Indices and sites commonly do not map drought or moisture excess the same in the different climate divisions of the country.Users of these indices should compare them with each other to determine which ones seem most appropriate for their part of the Nation. 6.1 PRELDHNARY NATURE OF NEAR-REAL TRgE ANALYSES Near-real tune drought indices are calculated from preliminary data that have not undergone quality-control protocols.Therefore,the Palmer drought indices and the Standardized Precipitation Index should probably not be used in reports until the indices have been recalculated with official data; this is especially true of the weekly updates of the Palmer indices published by the Climate Prediction Center (Section 6.2,below).Quality control is usually completed after three months time for the drought indices. The updated calculations are mserted into published files automatically,so indices for the preceding three months should be considered preliminary and those four months or older can be assumed official(R, Heim,NCDC,personal communication,July 1999).Changes in SPI data after quality control are usually so small that SPI indices are not updated on the NDMC Web pages(M Svoboda,NDMC,July 1999, personal communication),the disclaimer at their Web site notwithstanding: httl2-//e-ri-5o.uni.edu/ndmc/watch/clatadis.btm, Real-time stream gauge data,too,are preliminary and need to undergo quality-control protocols before being cited.The USGS disclaimer says that"data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences"(USGS 1999a: hU://water.usgs.goy/orovisional.html). 6.2 PALMER DROUGHT INDICES Every month the NCDC publishes four Palmer Drought Indices:Palmer Drought Severity Index (PDSI),Modified Palmer Drought Severity Index(MPDSI),Palmer Hydrological Drought Index (PHDI), and Palmer Z Index at the URL:htty://www.nodc.noaa.gov/onLingprod/droughttmauLhtmi(Figure 9).The 25 Palmer Drought Data Predpitadon(Iftehes) 7.0 6.0 Palmer Z lodes 4.0 LLJ L Niodirwd Palmer Drought Severity Indcz 2.0 — 010 —--------------- -4.0 P.almur HY&U10sical Drought IU&JL 4.0 --- 2.0 =w5w am LW Rig RF*1 0.0 -2,0 -4,0 Palmer Droughl S nvcniy lodes 0.0 -- -2.0 -4,D Jan Peb Mai, Apr May Jun Jul AZT Sep Oci Nov Dec Nebraska-Division US- 1991 (-Monthly Averages) FIgure9. Palmer drought indices for Climate Division 5, NE,(includes Grand Island)for 1991 (ht!p//www.ncdc.noaa.soy/oniineprod/drousht/xmpre2.htm1;NCDC,nd) 26 i Climate Prediction Center also publishes the PDSI on a weekly basis at: http•//www cpc nemmoas eov/products/analysis monitorinvjiepional monitorine/nalmer.ei� (Figure 10). Each Palmer index models both deficit and excess of precipitation,and each is calculated as a function of precipitation and temperature over a period of weeks to months.Evapotranspiration and soil moisture content are inferred from the measured precipitation and temperature data.These indices are widely used by state and Federai agencies to classify drought in the Nation.The Palmer indices complement the WETS Tables in that they integrate several components of the hydrologic budget.The Palmer indices also are sensitive to climatic patterns that are longer than just a month or two. The PDSI,MPDSI, and PHDI differ from each other in rapidity of response to change in precipitation and temperature patterns:the PDSI responds most rapidly,the PHDI most slowly, and the WDSI at an intermediate rate(Karl and Knight 1985).The PDSI should probably be used to approximate meteoric drought in precipitation-driven wetlands.The PHDI would be more appropriate to approximate drought in groundwater-driven wetlands.Usually the three drought indices can be interchanged with each other for wetlands purposes because most of the time the differences between them are smaller than the error of extrapolating from the regional scale of the indices to the site-specific scale of a wetlands permit.Remember,for site-specific evaluations the drought indices provide a long- term,regional context in which to interpret the more locally specific information of the WETS Tables The Palmer Z-index is probably the least useful for wetlands purposes because it provides a short-term adjustment to the PDSI that reflects short-term precipitation deviations from the longer term PDSI, Differences between the Palmer indices are discussed in more detail at http://www.ncdc.noaa.eov/onlinepmd/dmugbt/readme.html and http.//enso unl.edu/ndme/enigma/mclices.htm#odsi Except for the Z index,positive numbers in these indices reflect wetter than median conditions, and negative numbers reflect drier than median conditions(Table 4). Note that in analogy to the WETS Tables,the range of normal in this scheme is from the 281h to 72"d percentiles rather than the 30"'to 70d' percentiles. These differences are probably insignificant because the confidence intervals about these climatic statistics are likely greater than the differences between these two ranges of normal(P. Pasteris, NWCC,personal communication, 1999).The Palmer indices are calculated from data from 1931 to the present,whereas the WETS Tables are calculated for the most recent three decades. More important than the fine differences between the Palmer indices,however,is the fact that these indices are regional in nature and are not site-specific Hydrology at a particular site may differ from the regional pattern because of localized rainfall events and because of site-specific soil conditions.For example, the PDSI(Figure 9)indicates that drought conditions in June and July 1991 were slightly below median and within the range of normal in Division 5 of Nebraska, which includes Grand Island,NE,and that the Division averaged approximately 2.5 and 2 inches of rain in those months, respectively.The precipitation record at Grand Island itself,though,reports that 5.25 and 5 74 inches of rain fell there in June and July 1991,respectively(Figure 1). Advantages of the Palmer Drought Indices are: • Data are current. • The drought indices integrate precipitation,soil moisture,and evapotranspiration into one value. • The information is easily accessible. 27 DROUGHT SEVERITY INDEX BY DIVISION (LONG TERM PALMER) JUL 31, 1999 Bas6d an prollminary data t I . -4.0 or loss(EMEME DROUGHT) ■ -3.0 to-3.2 (SEVERE OROUONT) -2.0 to .Li(UNUSUAL MOIST SPED -2.0 fa-2 9(MODERATE MUMM r ,3A to .30(WRY MOIST SPn* J. ❑ -1.9 fa +1.9 (NEAR NORMAL) *4.0 and almo(EXTR WY MOIST) CUMATE PREDICTION CENTER, NOAA Figure % Example of Palmer Drought Severity Index by climate division for the Nation from provisional data atlhe Climate Prediction Center (hffp://www.cr)c ricer)noaa aovJproducts/analysis monitoring/regional monitoring/oalmer aifi NCDC,nd) 28 Table 4. Palmer Classes for Wet and Dry Periods (NCDC 1994). Approximate Cumulative Frequency Palmer Drought Severity index A (percentile) Modified Palmer Drought Severity PalmerZIndex % Index Palmer Hydrologic Index z96 n400 a35 90 to 95 3 00 to 3 99 2.5 to US 73 to 89 15 to 2.99 1.0 to 2 49 28 to 72 -1.49 to 149 -124 to 0.99 11 10 27 -1 50 to-2 99 -1 25 to-1.99 5 to 10 -3 00 to -3.99 -2 00 to-2.74 s4 s4.00 s275 • Data can be converted to percentile frequencies from Table 4. • The NCDC Web site publishes data for both national and historic coverage(Figures 10 and 11). Disadvantages of the Palmer Drought Indices are: • The Palmer indices do not distinguish between snowfall and rainfall. • The conversion to percentiles is only approximate given the resolution of the graphs at the URL. • Indices are not site-specific. • The most recent indices are provisional and subject to change,so should not be reported in legal documents. • Some of the assumptions in calculating soil moisture content may not be valid for the specific site being evaluated. Utility: Palmer drought indices complement WETS Table analyses by(I)evaluating evapotranspiration and soil moisture content as well as precipitation inputs and(2)providing longer term analyses than do the USDA Engineering Field Handbook and associated methods(Section 4 above). The most appropriate Palmer or SPI index should be used to determine occurrence of long-term drought or excess in a region once the indices have been recalculated with official data Real-time Palmer indices should be consulted to get a sense of regional drought patterns. 63 STANDARDIZED PRECIPITATION INDEX(SPI) The Standardized Precipitation Index(SPI)is a relatively new index that reports precipitation totals as exceedence frequencies for the Nation's 350 climate divisions.It differs from the WETS Tables 29 O O O 0 0 0 Q O O 0 0 0 Coco 0000 0000 00 4 0 M tQ to O)tO OI 05to0 MIDM A ioMO 1 0;to O;O o7 to M 0 o7 tOM0 1 L1... ...-1_..1� L-, I I T -� i_I ! j , Ti ! ! i z z 4 ° 1 , ' • �_�� 1 Y a I W -1 l7 an o, w 01 03 � @ 1164 4 L f - a 0 a 30 in that it calculates exceedence frequencies for several different time periods(1-,3-,6-,9-,and 12-month periods of accumulated precipitation).SPI information is available at. hM://enso.unl.edu/ndmc/watch/watch,htm#section (scroll to hyper text link"Current Standardized Precipitation Index Maps") or httn://www wrcc dri.edu/spi/spi.html. The SPI itself is a numerical index varying between-2 or less and+2 or more.Values between -0.99 and+0.99 represent precipitation amounts with exceedence frequencies between 16 and 84 percentile(Table 5). This is a wider muddle range of exceedence frequencies than used by either the WETS Tables or the Palmer indices.Thus,it is difficult to compare the SPI with them.The Western Regional Climate Center(btto//www wrcc.saae dri.edu/spi/spi.html]uses the SPI raw data set to create curves of percentile exceedence frequency vs time(months prior to query date).These curves are much more useful than the SPI itself because they show all percentile levels between 0 and 100,including the threshold levels used by the WETS Tables and the Palmer indices.Exceedence frequency percentiles are available in graphical format(Figure 12)for twenty time periods preceding the current calendar month, going back five years.Interpretations of SPI's calculated at different time scales are discussed at http://enso.unl.cdu/ndme/watch/intgM.him. Both the plot of precipitation percentiles for various preceding time periods(Figure 12)and the NRCS Engineering Field Handbook method provide calculated estimates of cumulative precipitation inputs for more than one preceding month.The MRCS method weights earlier months progressively less whereas the SPI calculates exceedence frequencies without any weighting factors It is up to the user to decide which time period is of greatest significance to his or her needs when using the SPI.In some situations two months'preceding precipitation may explain water levels whereas in other situations it may be several months. Advantages of the SPI Web site are: • This is the only easily accessible analysis that the authors know of that presents precipitation exceedence frequency data for time periods longer than one month for all the climatic divisions of the Ration. • Regional patterns of drought or excess are quickly observed from the Web site;the WETS Tables present only one station at a time. • Exceedence frequency percentiles are not limited to discrete class thresholds, such as 301' and 70" percentiles for the WETS Tables. Disadvantages are: • Indices are not site-specific. Calculated exceedence frequencies are not weighted for length of time prior to a month of interest, in contrast to the method of the MRCS Engmwnag Field Handbook(Section 4.1) • Indices published at this Web site are usually a couple of months old. • As of this writing,historic SPI's are archived only back to 1996 (h4p://enso.unl.edu/ndme/watch/watch.h=). 31 Table 5. Exceedence Thresholds and Percentiles for SPI Values' SPI Ixceedence Threshold Percentile 2 00 or more 2 3 percent 977 150 to 1.99 44 percent 956 100 to 149 9 2 percent 9o,a 0 to 0.99 15 9 peroene 841 0 10-0.99 84 1 percent' 159 - -1 00 LO A 49 916 percent 92 -1.50 to-1 99 95 6 percent 4.4 -2 00 or less 97 7 percent 23 'National Drought Mitigation Center(1990) ]Exceedenee thresholds for 0 to 0.99 and-0.99 to 0 ranges as reported by National Drought Mitigation Center(1996)should be replaced wah values In this table(Mark Svobode,NDMC,July 1999,personal communication) Utility: • The SPI Web site reports cumulative precipitation in terms of percentiles for many different time scales.It can provide a longer term perspective on drought than do the analyses recommended for the WETS Tables,The SPI analyzes only precipitation and, therefore, complements the Palmer indices,which reflect many assumptions about soil moisture characteristics and evapotranspira- tion,The SPI has been most widely used in the West,which is the region where the Palmer indices might be weakest due to questionable assumptions about snowmelt,runoff,and spatial homogeneity of drought. 6.4.USGS STREAM GAUGE DATA The USGS provides near-real-time streamflow data and summary graphs from around the Nation at http://water.usgs.Qov/realtime htmL Real-time gauge station data for individual streams and lakes can be accessed by clicking on the U.S.map and following the menus.The national and state maps of streams are color coded by percentile classes,including one class that is comparable to the range of normal defined on the WETS Tables.Real-time data for individual streams are accessed through the state map Web pages.Many state pages provide 20-,50-,and 80-percentile thresholds for gauge data for individual streams;these percentiles are presented at the bottom of the page with recent gauge data in graphical format(Figure 13). Exceedence frequencies of historic stream gauge data are more difficult to access on the Internet. Historic data can be found at hM:Ilwaterdata.usp,&.gov/nwis-wfU$ . USGS State Representatives can then supply frequency analyses for specific gauges and dates.A directory of State Representatives is at: httn://watLr.uses.Lrov/statereg html.Further information on the USGS stream gauging program can be found at httTW/water.usgs.goy/public/pubs/circl123/overview.html#HDRI (Wahl et al, 1995) 32 - . a 2a\ ) /\ S«Q \�2 k2 / C) CD � § �) $ § { « ! ) -- ------- ----- -- - -- - 7 ] / f a k ! . - - � a g } 2 - - - - -- -- - -- -- , � I u 0 Qp* / / Q '� • Z! \ \j k 77/] cc WA —2 cu \� ) a i oaa . ■ 0 0 33 10851650 TRUCUE R AT WADSWORTH: NV 0 500 T. --- cWri 400f - ' -- —� 304 - — _ ----�--- - - LU LL --__._y_ 4 -� m cJ 200U. - I i 11 12 13 14 is is 17 is Septenber 1999 Fri Sep 17 09:30 1999 STREHNFLON NEON DOILY STRERNFLOR, based an 22 years of record Provisional Bata Subject To Revision Daily Mean Flow Statistics for 09/17 based on 22 years of record,in ft3/s Latest flow FM-inim—uml � 80 percentFesilceedancolexceeddene percent 20 percent Mesn Maximu exceedanc 335 14 241 1,700 30 j 441 Percent exceedance means that 90,50,or 20 percent of all daily mean flows for 09/17 have been Veater than the the value shown. Figure 13. Example of USGS streamflow graph at USGS website,including table of exceedence thresholds(http://water. sas.00v/realtime.html, USGS 1999b) 34 Advantages of this information are. • Current information is available. • Streamflow rates integrate several elements of the hydrologic budget,including precipitation, groundwater flows,runoff and evapotranspiration. • Regional patterns of drought or excess are quickly observed from the Web site;the WETS Tables present only one station at a time. • The data are reported in exceedence frequency ranges rather than just absolute elevations or rates. Disadvantages are: • Hydrologic regimes at some sites may not correlate with streamflows. • Exceedence frequency information on historical data is cumbersome to obtain. • There are fewer stream gauges reported at the USGS Web site than there are NWS stations reporting in the NWCC WETS Tables(2100 vs 8000+;Harry Lms,USGS Office of Surface Water,personal communication,July 1999). • Exceedence frequencies are calculated for the period of record rather than for a set time period,so calculated percentiles are not strictly comparable between gauges. Utility: • The stream gauge data at this URL reflect hydrologic conditions upstream of the gauging stations. They therefore complement the indices of precipitation inputs in evaluating hydrologic conditions at nearby investigation sites.Because of the provisional nature of the data,the information at the site should not be used in formal reports before consulting the state USGS Water Resources division office to verify the accuracy of the preliminary data presented on the Web site. 35 7. GEOGRAPHIC VARIATION IN PRECIPITATION Common experience tells us that daily precipitation vanes even within a radius of a few miles. Consequently,there is always the concern that precipitation affecting a site may vary significantly from that recorded at the nearest weather station.Therefore,rain gauges are often installed onsite in research situations. If onsite rain gauge data are not available,determine whether or not precipitation was within the range of normal at NWS stations of comparable elevation within a radius of 30 miles(30 miles being the radius that the National Climatic Data Center[1995]uses to select neighboring stations for estimating missing data). If temporal variation was comparable among the stations evaluated,assume that precipitation at the site in question varied in the same way as the majority of the stations evaluated An example from the Reno/Tahoe area of California and Nevada provides insight to geographic variation in precipitation.Figure 14 shows the precipitation levels as percentiles of monthly precipitation in 1979 at four different weather stations in California and Nevada: Colfax,CA;Tahoe, CA,Virginia City,NV, and Reno,NV. These stations are located up to 85 miles apart in four orographrcally distinct regions:the western foothills of the Sierra Nevada, the crest of the Sierra Nevada,the eastern foothills of the Sierra Nevada,and the eastern rain shadow desert in Nevada.Absolute differences in average annual precipitation range from 7.5 inches at Reno to 46.5 inches at Colfax.The year 1979 was chosen because total precipitation was approximately average and there were no rmssmg values at those stations that year. Station characteristics are summarized in Table 6. Several lessons can be drawn from Figure 14 and Table 6: • Despite geographic differences,overall patterns of rainfall are similar across the orographic rainfall divide. ► The further precipitation deviates from the mean,the more similar records tend to be(note fluctuations from June to July,and September through December). • The greater the distance from a site,the greater the deviation in precipitation pattern. Mere,the most distant station,Colfax,showed the greatest deviation from the common pattern(wetter than normal January and February,drier than normal August). • Precipitation should be compared within geographically similar regions.Note that precipitation in May at the two desert sites was on the dry side of normal and in the mountains was wetter than normal 36 Colfax , ' Reno Virginia City / Tahoe 0.8 c - d 0.4 /m o ]Nevada 0.2 .1 I Reno Tahoe] Cafax k,virginia cif` ' 1979 0.0 M ti Q °? Oa g -, '� Q v1 Z 0 Figure 14, Precipitation patterns across the Sierra Nevada divide expressed as percentiles of monthly t precipitation (MCC 1996) Normal precipitation is between the 30ei and 71P percentiles (shaded light gray). See text for further discussion Table 6. Characteristics of Contrasting Weather Stations in the Tahoe/Reno Region. Colfax,CA Tahoe,CA Virginia City,NV Reno,NV Distance from Reno, 85 33 18 0 miles Elevation,feat 2410 6230 6340 4400 Ave,annual precip, 485 32.3 1485 7.53 Inches Geography Western foothills of Sierra Nevada Virginia Range of Besln Truckee Basin of Basin Sierra Nevada range mountains &Range Province and Range Province Climate(Trewarthe 1968) Temperate Oceanic Temperate Conlinental Sbor nt- rid,temperate Arid,temperate boreal 37 S. COMPARING DATA FROM MONITORING WELLS AND RAIN GAUGES Antecedent precipitation is often compared monitoring well data.Therefore,two examples of such comparisons are provided,one from a site where water levels in wells track precipitation inputs closely,and a second where the response is less well defined.The methodology requires overlaying time series analyses of wells and precipitation adjacent to each other.A template for these figures is in Appendix C. Figure 15 shows the second of three years of data from a site with rapid water well response to precipitation inputs.The well is located in the Columbus,OH,area at a slope break at a floodplain-upland transition. Water levels were read twice daily by an automatic recording device. The soils are likely to conduct shallow interflow in the silt loam surface above a relatively impermeable argillic horizon(Soil Conservation Service 1980) Therefore,precipitation enters the soil and 40-mch-deep water well by direct infiltration and by imertlow from upslope.The argillic horizon allows relatively little discharge from or recharge to deeper groundwater. Note the short duration peaks in water level response to precipitation inputs during the spring of 1997.These are what one would expect from intertlow inputs rather than from groundwater discharge. These flashy spikes tend to start at the boundary of the silt-loam topsoil and clay- loam argilhc horizon in April,May,November,and December. There were two water level spikes in September 1997 at the study site and only one large precipitation event The second spike probably resulted from a locally heavier thunderstorm input at the study site than at the rain gauge seven miles away.Other wells onsite also recorded the second spike in late September,so the discrepancy between water levels and rainfall records cannot be attributed to monitoring well malfunction. The rapidity of water level response at this site is striking.In late August it took less than a week for water levels to drop to the top of the argillic horizon,despite the heavy rains in the first half of the month.It seems appropriate to evaluate antecedent precipitation for 30 days rather than several months in this setting.The sluggish water table drop to 2 '/Z feet or more in the late summer or early fall probably reflects one of two possibilities: (1)There really was a water table in the argillic horizon and water tables dropped out of it as slowly as the well records indicate;or(2)water from the A and BI horizons ran into the well and seeped out into the nearly saturated argillic horizon only slowly. Considering the sluggish drop in water tables in midsummer when evapotranspiration was high,the second explanation is worth checking out with a drawdown test in the field(blame and Smith 1995). Figure 15 also shows the difference between monthly,daily,and 30-day rolling sums of precipitation data.Monthly sums would indicate that May was a wet month,but the 30-day rolling totals show most of May to have been normal in precipitation.The daily data provide the explanation for the difference,in that almost half of the month's rain fell in the Iast three days.Here the 30-day rolling totals depict precipitation inputs more accurately than does the monthly sum. Figure 16 is an example of a system where water levels fluctuate more slowly in response to precipitation inputs.The soils here(Boone Creek,IL)are shallow mucks(16-23 inches thick)over alluvium.The wetland hydrology has strong groundwater discharge components as well as overbank flooding(Richardson et al., 1997) Furthermore,the muck soils hold water much longer than do the shallow topsoils of the Columbus,OH,area shown in Figure 15.Both years of data in Figure 16 show a significant drop in water levels during the summer,due to evapotranspiration.However,precipitation inputs were much higher tin May 1996 than in May 1995,delaying the spring evapotranspirative drawdown by about a month.After the heavy rams in May and June 1996 abated,groundwater levels dropped to their 1995 depths,but four heavy rain storms in July and August induced water levels that 38 d U M d � O � _a O z � E O � C M CD V. .t m +8 T U N mz mQ a_ c 0 cU CD > ; 00 /��W E N €g N U a O `m co d a r — GE O o d Mo ® • � 10 7 N � O � 'gs � M .� � ("42uo uamc 4m+ 3 (IoaJ? 4i+o6 g 3 0 $ roAn jeseM 9*Bpnwueaup m g cc i G'M LoO rn LL 39 m_.tow,______ . (WSJ) , m LO ! \ g � . $ � @ ± , § v � / . sf CD � � _ _ co { I \ ■ ! $� a � ■ � � ) & � % $ U $ ` ) \ f , cricn . kf | _ � � d f ` ! # + t �— ! } ƒ ` a) cc � / 40 •poea_,_m©___, Ives;) u k � 2 _ A J k 2 _ „ co 2 � \ � � © ca ! CL ¢ � � o ` _ _uagq_w , 0 2 k EL || ! \ ! % \ ! ! ! § ! � ) f ! ■! /a ®s \� �e \ £ 41 were much higher than in 1995.Note that after the August 23, 1996,rain storms the water levels stayed hugh for a few days to a week,but two weeks later had dropped to their 1995 levels These two examples—shallow,mineral,interflow system versus muck soil on the floodplain of gaining stream—indicate the advantages of daily precipitation data from NW S sources as opposed to monthly data from the WETS Tables in interpreting the overall hydrology of a site.in the Ohio example the responses to rain and evapotranspiration were rapid and would have been inexplicable or missed altogether without daily data;in the mucks of Illinois water tables dropped more slowly after the rains stopped.In both cases daily data were important in interpreting water table fluctuations and understanding key processes driving the hydrology of the sites. 42 9. STATISTICAL BACKGROUND AND COMMON PROBLEMS I 9.1 GAMMA DISTRIBUTION:INTRODUCTION TO THE STATISTICS OF NORMAL PRECIPITATION Fundamental to precipitation data analysis is the fact that precipitation data for most of the Nation do not fit a bell curve("normal distribution").The reason for this is that the probability distnbution3 for precipitation is not symmetrical. The left-hand tail of the distribution is bounded by zero,because there cannot be less than zero precipitation in any given time period.The right-hand tail,on the other hand,has no theoretical upper limit. The statistical evaluation method that best describes precipitation data is called a gamma distribution,which is a theoretical curve similar to the Gaussian distribution but skewed to the right. To explain the gamma curve and probability distributions more fully,let's pursue the comparison between normal and gamma curves.For example,if you wanted to know something about the heights of 30 students in a class,you would find the mean and standard deviation of the sarnple4 and develop a normal curve.In a similar fashion,meteorologists take the 30-year-long sample of a particular month's precipitation data(30 Aprils,for example)and fit that sample to a gamma curve.Neither sample of 30 individuals(heights or rainfall months)fits its theoretical curve exactly,but experience has shown that the populations of student heights or rainfall months are best described by their respective theoretical curves. (See Appendix D for a more technical discussion of frequency distributions of precipitation and temperature data.) Figure 17 shows the frequency distribution of a sample set of monthly precipitation totals in two formats: a simple histogram and the smoothed curve of the gamma distribution for the population inferred from that sample.X-axes are the same for both graphs inches of April precipitation at Grand Island,NE. In concept,the Y-axes are the same,too-frequency of the X-axis amounts. In the histogram the Y-axis frequency is simply the number of April precipitation months with a given amount of ram divided by the total number of Aprils sampled,for example, 9/30=0.3 for the second bar(1.00-1.99 inches). The mathematics are not quite so straightforward for the Y-axis for the idealized curve in Figure 17 but the concept is the same:increasing probability of occurrence with increasing height on the Y-axis.A principal advantage of the calculated gamma curve is that it allows interpolation and extrapolation based on the existing data. The histogram and gamma curve is Figure 17 have similar shapes,and both of them depict the same qualitative concept: the likely rainfall amounts in April at Grand Island,NE The histogram of the 30-year sample(Figure 17)is limited to Aprils between 1961 and 1990.Most Aprils during those three decades had between I and 3 inches of rain at Grand Island.A few Apnls were wetter;two were very 3 Probability distributions are patterns of occor once far populations of data-The best known pmbability distribution is the "normal distribution,"this is also]mown as a"bell curve"or a"Gaussian distribution" Many,but not all,natural phenomena fit a normal distribuhon.For example,plant heights within a species fit a normal distribution,radioactive decay is best described by a Poisson distribution,and precipitation fits a gamma distribution. 4"lf a set of data consists of all conceivably possible(or hypothetically Possible)observations of a given phenomenon,we cell it a population,if a set of data consists of only a part of these observations,we call it a sample"(Freund 1988,emphasis added) For example, the amounts of precipitation at Grand Island,NE,for the thirty Apnls between 1961 and 1990 comprise a sample, 1 the population from which the sample was taken consists of all possible amounts of April precipitation at Grand Island since the last significant climatic change.The discipline of statistics analyzes date from samples to infer general patterns about populations. 43 10 0.3 A. Histogram 9 w 8 Grand Island, NE NWS Station 0.2 1961-1990 6 C 5 0 L 4 d 0.1 3 a 2x 1 0 0 0 0 R 0 0 0 0 0 0 o a o 0 0 p �- LV ed 'i to <o Range of Monthly Total Rainfall for April (Inches) 0.3 B. Gamma Curve 0,2 Grand Island,NE NWS Station 0 1961-1990 Cr LP U. m 0.1 �Y m o Y_ L e J d Y �y ,E O 0 1 2 3 4 5 6 Range of Monthly Total Rainfall for April (Inches) Figure 17. Histogram and gamma distribution for same set of precipitation data(Apnis 1961-1990, Grand Island,NE; (NWCC 1966)). X-axis is inches of April precipitaton in both figures. Y-axis is a measure of relative frequency,for example,second bar in Figure 17A is niinww =9 months 130 months=0.3. Y-axis in gamma distribution is also relative frequency, but idealized to total number of possible occurrences 44 much wetter, with between 6 and 8 inches of rain.If you think of the histogram as having tails,the aght- hand tail is longer than the left-hand tail, the data are skewed to the right. The gamma curve for the population of April precipitation at Grand Island(Figure 17)is estimated by fitting an idealized curve to the 30-year sample.Comparing the gamma curve and the histogram it is obvious that some Aprils in Grand Island will have between 5 and 6 inches of precipitation.There is no rational explanation for that gap in the 30-year sample other than random chance.The gamma distribution smooths the 30-year sample data to fill in such gaps and describes the gamma curve that fits the 30-year sample most closely. The three vertical lines marked"30,50, and 70%likelihood"on the gamma curve indicate the precipitation amounts at the 30th,50%and 70'h percentile levels,from left to right.The 301h and 701h percentile levels represent the lower and upper thresholds of normal April precipitation at(nand Island (although other boundaries of normal such as 251h and 7511,percentiles could be calculated).Half of the Aprils are predicted to have less than the 500'percentile level,2.09 inches. These values can be calculated from the frequency distnbution of 30 monthly rainfall values,too,by rank ordering the 30 values and lopping off the nine highest and nine lowest values.When this is done,ranges of normal are 1.39 and 2.79 inches. Two points need to be made about the comparison of the histogram and gamma curve. Average April precipitation is not in the middle of the frequency distribution.Average April precipitation is the arithmetic mean of the 30 Aprils in the histogram.This is 2.50 inches (Figure 1).The middle of the frequency distribution of April precipitation amounts is the 501h percentile. This is 2.09 inches.The average is greater than the median value because the probability distribution is skewed to the right. The ranges of normal April precipitation are slightly different using the histogram and the gamma curves: 1.39 to 2.79 inches versus 1.37 to 3.05 inches,respectively.This difference underscores the difference between samples and populations of data.The gamma came gives the preferred estimate,which is the one found in the WETS Tables,because it is determined from the statistically smoothed 30-year sample. 9.2 ARID LANDS In contrast to the humid east and south,monthly precipitation levels in and lands vary greatly from year to year and may include zero precipitation for months on end.For example,Figure 18 reports July precipitation for 1961-1990 in Mojave,CA.Note that 19 of the 30 Julys within the three-decade reporting period had zero precipitation.It is obvious that the most likely precipitation level in July at Mojave, CA,is no rainfall at all.Normal precipitation is 0.00 to 0.08 inch;that is,the wettest 30 percent of the Julys between 1961 and 1990 had more than 0 08 inch of rain,and the driest 30 percent of the Julys between 1961 and 1990 had 0.00 inch of rain.In fact,the concept of"less than normal"has no meaning in this extreme climate. "Average"precipitation,too,has little meaning in deserts,because of how extremely skewed the distribution is;the arithmetic mean(0.16 inch)is twice as high as the highest "normal"rainfall(0.00-0.08 inch). 45 Southem Calftomia I a I 20 0.6 Mojave,CA 18 m NWS Station 0 0.5 1961.1990 16 m 14 3 m 0.4 12 O Cr 0.3 10 C u_ 8 �. 0.2 6 0 0.1 4 3 pp Q 2 Z O NU� ti O N ti O N O Q O e= N CV CV O N to � O N tp t0-, O N O O 6 6 TZ r +r sr N N Range of Monthly Total Rainfall Depths for July (Inches) Figure 18. Histogram of July precipitation at Mojave, CA,for 1961 to 1990. Note that more than half of the Julys had zero precipitation(NWCC 1996) 9.3 BIMODAL PRECIPITATION Many people assert that the majority of years have either very high or very low precipitation amounts. They feel that Junes, for example,are either wet or dry,with relatively few Junes having intermediate amounts of rainfall This would imply that the June rainfall distribution is bimodal,and, hence,the unimodal gamma distribution does not describe the probability distribution of precipitation in their part of the country.Meteorologists,however,have analyzed precipitation records around the world and found that precipitation in the vast majority of places is best described by a ummodal model, although rain falls in some places in the tropics with truly bimodal frequency distributions(Granger 1987). Two regions of the country where this misconception is most common are the and West and the hurricane zone of the Southeast.Analyses of longer tern precipitation records in the and West(70 years at Ogden,LTf,and 60 years at Bakersfield,CA;NWCC 1996)show that the right-hand tail of the frequency distributions tends to be flat,so these precipitation distributions are still unimodal.Along the 46 Southeast and Gulf Coasts and in the Caribbean,late summer and autumn tropical storms may seem to cause truly bimodal rainfall distributions. Even these distributions,however,are usually ummodal over a long period of record Compare,for example,the 30-year vs 96-year records at Raleigh,NC(Figure 19); although June is not in the height of he hurricane season,the 30-year record shows a strong possibility of bimodality.Histograms of major cities along the south Atlantic and Gulf coasts from Wilmington,NC,to Galveston,TX,throughout the summer and autumn indicate that tropical storms do not create bimodal precipitation distributions in the region,possible exceptions being southern Florida and Puerto Rico. 47 Frequency A. Raleigh,NC NWS Distribution of 0.2 June Station 1961-199020 _ Rainfall e a a 0.1 10 U. U. 0.0 0.0 o g o o $ o o $ o 0 0 C? q p C? f` Cd Oi O { p T T r { T T O O O O O O CD O r0 O p r LV 6 4 L6 Ed ti Co Cri O 0.2 Frequency B. Raleigh, NC NWS 20 Distribution of June Rainfall Station 1900-1990 c a m e S 0.1 10 Cr - c LL 0.0 0.0 o g o o 0 CDa g a c Chi T T r T T { { T r r O O O O O O O O O T r 6 s- CV C4 4 6 CG r: 6 O O CA C T Rainfall Depth (Inches) Figure 19. Frequency distributions of June precipitation at Raleigh, NC. The 30-year record(1961.1990,top graph)shows the possibility of bimodal precipitation with a second small peak at the end of the right-hand tad. The total record(1900-1990.bottom graph), however,shows the distribution to be unimodai. The X-axis is inches of June precipitation; Y-axis is the frequency of Junes with X-axis amounts of precipitation (NWCC 1996) 48 10. SUMMARY AND RECOMMENDATIONS 10.1 SUMMARY 1. Characterization of the long-term hydrology of a site requires evaluation of meteorologic conditions prior to and during the assessment period. 2.Evaluation of meteorologic conditions typically involves determining whether current precipitation is normal,wetter than normal,or drier than normal during the assessment period This requires knowledge of both historic rainfall frequencies and rainfall amounts at the time of assessment. 3.WETS Tables,which were generated by the NW CC for more than 8000 NW S stations across the U.S.,provide information for detertruning the range of normal rainfall conditions for a site. WETS Tables also provide accurate assessments of the growing season for a site. 4. Precipitation amounts at the time of the assessment can be obtained from the Regional Climate Centers and State Climatologists. The UCAN network should provide real-time precipitation records in late 1999. 5.Onsite rain gauges may be used to identify daily differences between precipitation onsite and at NWS stations,and are particularly valuable in areas where geographic distribution of rainfall is patchy. 6.Relatively quick and easy-to-follow methods are presented to evaluate antecedent precipitation at a site. These include: a.Method ofNRCS Engineering Field Handbook b.Method of 30-day rolling totals c.Method combining(a)and(b)above 7.Regional measures of drought and precipitation excess are available on a near real-time basis at Internet Web sites run by the NCDC and the NDMC. 10.2 RECOMMENDATIONS 1.Precipitation antecedent to a date of hydrologic monitoring should always be evaluated to determine whether it was within the range of normal for the site. 2.The NRCS WETS Tables should be used to determine monthly ranges of normal precipitation unless other frequency distributions are available that are more site-specific. 3.When practicable,records of daily precipitation should be used to interpret monthly totals for deviation from range of normal.. 4.When practicable,a default duration of three months,weighted for recency, should be used to decide whether antecedent precipitation was within the range of normal prior to a date of monitoring.If local information is available about the duration of influence of precipitation on hydrology,that local kmowledge should be used to select the proper length of precipitation record to evaluate prior to a date of monitoring. 49 5, Wetland scientists with field responsibilities should keep up with regional patterns of drought or excess by referring to the various drought maps published by the NDMC and other sources of information on variation of climate(for example,state climatological experts).Local experience should guide selection of indices(Palmer,SPI,USGS streamflow,etc.)that seem to work best in the scientist's particular region. 6.Regional data published by the NDMC should be used to complement the more locally specific WETS Tables,not to replace the WETS Tables. i 7.Growing season dates reported in the WETS Tables are often preferable to those published in county soil survey reports because climate data are more recent. 8.If precipitation data are gathered from non-NWS stations,those data should be compared to daily records from surrounding NWS stations. 9.Wetland evaluations that use monitoring wells should provide comparisons of rainfall to groundwater levels. 1 50 11. REFERENCES Environmental Laboratory.(1987). "Corps of Engineers wetlands delineation manual,"Technical Report Y-87-1.U.S.Army Engineer Waterways Experiment Station,Vicksburg,MS. Finkelstein,P.L.,D.A.Mazzarelia,T.J.Lockhart,W.J.King,and J.H.White.(1983).Quality assurance handbook for air pollution measurement systems.Volume IV.Meteorological measurements.US EPA Environmental Monitoring Systems Laboratory,Research Triangle Park NC. Freund,J.E (1988).Modern Elementary Statistics.Prentice-Hall,Englewood Cliffs,NJ. Granger, O. E. (1987). "Precipitation distribution,"pp. 690-697,in The Encyclopedia of Climatology, (I. E.Oliver and R. W.Farrbridge, eds).Van Nostrand Reinhold Co., New York.. Jenkmson,B.J,and D.P.Frauzmeier, (1996). Soil moisture regimes of some toposequences in Indiana. pp 49-68, in Preliminary Investigations of Hydric Soil Hydrology and Morphology in the United States,J. S.W akeley,S.W.Sprecher,and W.C.Lynn(eds).Wetland Research Program Technical Report WRP-DE-13,U.S.Army Engineer Waterways Experiment Station,Vicksburg, MS. Karl,T.R.,and RW.Knight (1985).Atlas of Monthly Palmer Moisture Anomaly Indices(1931-1984) for the Contiguous United States,July 1985.Historical Climatology Series 3-9.National Climatic Data Center,Asheville,NC_ Kunkel,K.E.,and A.Court.(1990).Climatic means and normals-A statement of the American Association of State Chmatologists(AASC).Bull.Am.Meteorological Society 71:201-204. Microsoft Corporation. (1985-1997).Microsoft Exceil 97 SR2.United States of America. National Climatic Data Center. (nd).Climate division drought data:graphing options. http•//www.ncdc noaa,gov/onliMrod/drought/main html(accessed July 18, 1999). National Chmatic Data Center.(1994).Time bias corrected divisional temperature-precipitation-drought index.TD-9640.March 1994 http•//www.ncdc noaa eov/onlineprod/drou¢ht/readme.htnil (accessed June 16, 1999). National Climatic Data Center.(1995).U.S.National 1961-1990 Climate Normals,Climatography of the United States No. 81,Monthly Station Normals.NOAA,National Climatic Data Center, Asheville,NC. (Internet address http•//www.ncdc noaa..gov/normals/us/normals chm8l.html; September 29, 1995). National Drought Mitigation Center. (1996).Drought indices. http-//enso.unl.edu/ndme/enigma/mdices htm#ski. National Oceanographic and Atmospheric Administration.(1992).Climatological data:Nebraska, 1991. Volume 96,Asheville,NC. National Oceanographic and Atmospheric Administration.(1994).Climatological data.Indiana, 1993. Volume 96.Asheville,NC. 51 National Oceanographic and Atmospheric Administration.(1996). Climatological data:Illinois, 1995. Volume 96,Asheville,NC. National Oceanographic and Atmospheric Administration.(1997).Climatological data:Illinois, 19%. Volume 96.Asheville,NC. National Oceanographic and Atmospheric Administration. (1998). Climatological data:Ohio, 1997. Volume 96.Asheville,NC. National Water and Climate Center.(1996).Climate Analysis for Wetlands by County.Internet Web site h=://www.wee.nrcs usda.gov/water/wetiands.html(June 24, 1996). National Weather Service.(1989).Cooperative Station Observations,National Weather Service Observing Handbook No.2, Silver Spring,MD. Natural Resources Conservation Service. (1997)."Hydrology Tools for Wetland Determination,"Chapter 19,in Engineering Field Handbook,Part 650,210-vi-EFH.USDA Natural Resources Conservation Service Washington,DC. Office of the Chief of Engineers.6 March(1992) "Clarification and interpretation of the 1987 Manual" Memorandum for SEE Distribution. Washington,DC Richardson, 1.L.,J.P.Tandarich,and M.J Vepraskas (1997) "Soils of natural and created wetland biosequences,'Chapter 3 and Appendix BC,in"Studies of wetland biosequences of the glaciated Great Lakes region wet prairie to deep marsh,"Unpublished report to U.S.Environmental Protection Agency,Grant No.X995166-02-3,June 30, 1997 USEPA,Region V,Chicago,IL. Smith,J.A. (1993)."Chapter 3.Precipitation."pp. 3.J-3r47,inHandbookofHydrology,D.R.NJaidnietit, (ed.),McGraw-Hill,Inc.,New York- Soil Conservation Service (1980).Soil survey of Franklin County,Ohio.USDA Soil Conservation Service,Washington,DC. Soil Conservation Service (1984). Soil survey of Wayne County,Ohio.USDA Soil Conservation Service,Washington,DC. Trewartha, ,G.T. (1968).An Introduction to Climate,0 ed.McGraw-Hill Book Co.,New York. United States Geological Survey.(1999a) Provisional data disclaimer. brrp•//water.usgs.sov/orovisional.html May 25, 1999. United States Geological Survey. (1999b).Real-time water data httn//water usgs.gov/realtime html (updated July 27, 1999). Wahl,Kenneth L.,Wilbert O.Thomas,Jr.,and Robert M.Hirscb (1995).Overview of the stream-gaging program. U.S.Geological Survey Circular 1123,Reston,VA. (Internet Web site http_//water usgs.gov/public/pubs/circi l23/overview btmI4HDRI;July 1999). 52 Wame,A.G.,and L.M.Smith. (1995).Framework for wetland systems management:Earth resources perspective Technical Report WRP-SM-12.U.S.Army Engineer Waterways Experiment Station, Vicksburg,MS. Warne,A.G.,and D.E.Woodward.(1998).Methods to evaluate the hydrology of potential wetland sites: Wetland Research Program Technical Note HY-DE4.1,U.S.Army Engineer Waterways Experiment Station,Vicksburg,MS. Western Regional Climate Center.(nd).Precipitation percentile(non-exceedeace). http//www.wrcc dn.edu/czi-bin/sRiMAIN.pl?2601+sRil-Fpert72,accessed July I9, 1999. Woodward,D.E.,S.Jacobsen,A.G.Warne,M.Fritz,and V.Backland. (1996), Course Handbook, Hydrology Tools for Wetland Determination: Natural Resources Conservation Service National Employee Development Center,Fort Worth,TY, World Meteorological Organization.(1996).Guide to meteorological instr anent&and methods of observation.Sixth edition.WMO-No. 8.Secretariat of the World Meteorological Organization, Geneva,Switzerland. 53 APPENDIX A ADDRESSES FOR COLLECTION AND ANALYSIS OF METEOROLOGICAL DATA Al Table A-1. Internet Addresses Relevant to Wetland Jurisdictional Hydrologic Assessments Subject Internet Address Current weekly and monthly precipitation data for http•//www nnic.noaa eov/products/anaNsrs monitonne/cdus/prcp 225 US cities tiAnp tables/ Geomorphology resources http://tal.geoloay.touchio.edu/pbook/mmources.htir)l National Archives(historical photography) http.//www.nare.zov/nara/naildata.html NOAA National Oceanic Data Center bttp://www.nodc.noaa.Rovhndex.html NOAA hydrologic Information httn.//www.nws.noaa 8oy/oh/htc/hydrolinks1tml NWS Regional Climatic Data Centers hup.//met-www.cit.comell.edWother rcc html Remote Sensing-general information huD://www utexas edu/depts/prgtgcraft/notes/remote/remote.html Solis data http//www.statlab.iastate.edu:80/soils-mfo/ U.S.Army Engineer Waterways Experiment Station http://www wes.armv_nillel/wetlandstwlpu bs html W atland Delineation Manuel and other wetland documents U S Geological Survey Stream gaging and other http.//water uses t3ov/ water resource data U S.Geological Survey procedures for stream htty-Itwater.usgs.gov/public/pubs/cirel123hridex1tnil gaging State C imatotogists http•//www.nedc noes gov/oUclunate/aasc btnil#STATES UCAN(site In progress) http://www.woe nres usda gov/bbook/bb20.htm1 Hydrology Tools Method http//www wee arcs usda.gov/water/quality/textthvdrolog.btml Palmer Drought Indices http•//www.epc.ncep noaa.gov/products/analysis monitoring/ regional monitonn ahner. if Standardized PrecipRetion Index http//enso unl eduhtdmo/wateb/watch.htm#secdona Stream Gauge Analyses httn.//water usgs.aoy/realtime.html Various Drought Indices http.//enso.unl edu/monitor/current html U S Geological Survey Earth Resource Observation bttp://edcwww.cr.usgs gov/eros-home.htA Systems(EROS)maps and aerial photographs WETS Tables http,1/www wcc.rvcs usda.gov/water/wetlands html A2 REGIONAL CLIMATE CENTERS (Internet version: hM I/met-www.cit comell.edu/other rec.btm1) For AR,LA,MS,OK, TN,TX Southern Regional Climate Center;234 Howe-Russell Bldg.;Louisiana State University;Baton Rouge,LA 70803 Phone:(504)388-5021;FAX: (504)388-2912;htto://www.srce.isu edu/ For CO,KS,ND,NE,SD,WY high Plains Regional Climate Center; 15 L.W.Chase Hall;University of Nebraska;Lincoln,NE 68583-0728 Phone:(402)-472-6709;Fax. (402)-472-8763;http//hpccsun unl.edu/ For IL,IN,10,KY,M,MN,MO,OH,WI Midwestern Climate Center;2204 Griffith Drive;Champaign,IL 61820 Phone: (217)244-8226;FAX(217)244-0220;htto•//mcc sws.viuc.edu/ For CT,DE,MA,MD,ME,NH,NJ,NY,PA,RI,VA,WV Northeast Regional Climate Center, 1123 Bradfield Hall;Cornell University;Ithaca,NY 14853-1901 Phone:(607)255-1751;FAX(607)255-2106;htto.//met-www cit cornell.edu/ For AL,FL, GA,NC,SC,VA Southeast Regional Climate Center; 1201 Main Street Suite 1100;Columbia,SC 29201 Phone:(803)737-0800,FAX(803)253-6248;hats://water.dzinstate se us/elimate/serce/ For AK,AZ,CA,HI,II),MT,NM,NV,OR,UT,WA Western Regional Climate Center;5625 Fox Avenue/P.O Box 60220;Reno,NV 89506-0220 Phone:(702)677-3106;Fax: (702)677-3243 , httn://wwwwrec sage dn.edu/ NATIONAL WATER AND CLIMATE CENTER Natural Resources Conservation Service;National Water and Climate Center; 101 S.W.Main, Suite 1600;Portland,OR 97204 Phone: (503)414-3031;FAX(503)414-3101;htto://www wcc.ners.usda¢ov/wce.html STATE CLIMATOLOGISTS b-p:/Auww.ncde noaa¢ov/ol/elirnitWaase.html#STATES A3 APPENDIX B NWS Guide on Rain Gauges Excerpts from Observing Handbook No.2, pp. 6-19 BI SECPION 2: PRECIPITATION 2.1 INIROfX7C'i'ION There are two types of precipitation: liquid and solid. Liquid precipitation includes rain and drizzle. Since precipitation, by definition, falls to the ground, dew (which forms where it is found) is not precipitation. solid precipitation includes snow, hail, ice pellets, etc. Precipitation is measured in terms of its depth: a) liquid (including the water equivalent of solid precipitation which has melted) to the nearest hundredth of an inch, and b) solid to the nearest tenth inch. 2.1.1 PRECIPITATION GAGES In its simplest form, a precipitation gage is an open-mouthed can with straight sides, installed with the open end upward and sides vertical. Precipitation gages are also called rain gages. Improved gages record the amount of precipitation falling per unit time on a chart (usually a punch tape or rotating drum) . see section 2.2 below. 2.1.2 EXPOSURE OF CAGES The e r ++re of a rain gage is very important for obtaining accurate measure- ments. Gages should not be located close to isolated obstructions such as trees and buildings, which may deflect precipitation due to erratic turbu- lence. Gages should not be located in wide-open spaces or on elevated sites, such as tops of buildings, because of wind and the resulting turbulence problems. The best location is where the gage is uniformly protected in all directions, such as in an opening in a grove of trees. The height of the protection should not exceed twice its distance from the gage. As a general rule, the windier the gage location is, the greater the precipitation error will be. Wind shields (exhibit 2.1) may be used to minimise the loss of precipitation. This loss is much greater during snowfall than rainfall, so shields are seldom installed at cooperative stations unless at least 20 percent of the annual precipitation falls in the form of snow. In areas where heavy snowfall occurs; e.g., mountaireous areas in the western U.S., gages are mounted on towers at a height considerably above the max„msm level to which snow accumulates, at or somewhat below the level of tree tops. See exhibit 2.2. Good exposures are not always permanent. Man-made alterations to the area and the growth of vegetation may Change an excellent exposure to an unsatisfactory one in a very short time, necessitating the moving of precipitation gages to sites having better exposures. B2 PRECZPMUTON Exhibit 2.1., Wird Shield =r v" it \ 4 r E Libit 2.2 i 5 C ToWe B3 1MIGN 2.2 TYPES OF PRECIPITATIM GADS The specific types of gages now being used for measuring precipitation are: a) Nwrecording b) Recording (weighing type) 1) 8-inch gage 1) Belfort (Fischer & Porter) gage 2) 4-inch gage 2) Universal gage These are described below. 2.2.1 EIGffr-INCIi NO DOG GAGE This gage (exhibits 2.3 and 2.4) consists of the large diameter ocher can (in the left-center of exhibit 2.4), a smaller diameter measuring tube inside it (right-center) , a f:mnel that connects the above two (right). a up-Muring stick (bottom) . and a support (left in exhibit 2.4) . The outer can and top of the funnel are 8 inches in diameter. The funnel directs precipitation into the measuring tube, which is 20 inches tall and holds exactly 2 inches of rainfall (additional rainfall will flow into the overflow can) . This ten-to- one ratio makes it possible to read rainfall amounts to the nearest hundredth of an inch. The measuring stick is marked at .01 inch intervals. L - • � •y1 YEA 1 - • Exhibit 2.3: Eight-Inch Exhibit 2.4: Eight-Inch Nonrecordirg Gage, Assembled Nonrecording Gage, Unassembled B4 PRECIPI*1?ATZON 2.2.1.1 INSTA •ramr(W AND MAMMONCE The metal support (exhibit 2.4, left side) must be firmly =mted on a horizontal platform to prevent it from being blown or knocked over. The top of the gage must be horizontal. This should be checked by laying a carpenter's level across the open top of the gage in two directions, one crossing the other at right angles. If the top is not level in both directions, report this to the NWS representative. If you level the gage, please add a note to the observation form giving the date the defect was discovered and the date corrected. Teaks in the tube or overflow can should be _ reported pxrmptly to the NM representative. 2.2.2 FOUR-INCH NONREOORDING GAGE - The four—inch gage (exhibit 2.5) - consists of the outer overflow can BMW (lower left) , measuring tube (center) , a funnel (top) that catches the precipitation and directs it into the tube, and a mounting bracket with screws (lower right) . The gage is made of clear plastic. No measuring stick is needed because the measuring tube is graduated to hundredths of an inch. This tube holds exactly one inch of precipitation. Any additional amount will fall into the overflow can and can be measured as with the eight-inch gage (section 2.2.1) a - 2.2.3 WEYLGHING-TYPE RECORDING GAGE The weighing-type recording gage is , designed to record the rate and amount of precipitation. The precipitation rate is measured in hundredths or tenths of an inch per unit time. The amoum is measured in hundredths or tenths of an inch. These gages consist of a receiver with an inside diameter of exactly 8 inches that funnels precipitation into a collector mounted on a weighing mechanism. Exhibit 2.5: Four-Inch There are two types of weighing gages Nonrecording gage used by the NWS: B5 PRECIPITATION a) The punched tape type, manufactured by Belfort Instruments or Fischer & Porter (exhibit 2.6) , and: b) The universal type (exhibit 2.7). ram-- -'•. .ww — � T•yY p. , t n r 1 Exhibit 2.6: Belfort Exhibit 2.7: Universal (Fischer & Porter) Recording Gage Recording Gage 2.2.4 UNIVERSAL GAGE Precipitation falls into the universal gage receiver, where it is funneled into a collector mounted on a weighing mechanism. The weight of the precipitation in the collector compresses a spring, which is connected to a Pen (ink) arm. Ink fret the pen leaves a trace on a paper chart, which is wrapped around a clock-driven cylinder. the cylinder rotates continuously, making one revolution every 24 hours. Ink tracings on the chart provide a "history" of precipitation rates and amounts. Charts are graduated to the neatest .05 inch and may be read to the nearest .01 inch by interpolating between the graduations. The total capacity of the gage is 12 inches, although the chart is graduated to only 6 inches. When the 6-isuch mark is reached, the pen of the chart reverses direction. The reverse in pen direction is commonly referred to as "dual traverse." B6 PRECIPITATION 2.2.4.1 CALIBRATION AND EQUIPMENT PROBLEMS The gage requires occasional calibration and other adjustments to maintain its accuracy. This will be done by inspectors with special equipment. Clock failure, or any trouble that cannot be corrected as described below, should be reported immediately to the NWS representative. 2.2.4.2 GAINING ACCESS TO BUCKET AND CHUU MECHANISM You will need access to the chart and bucket in order to read or change the chart, wind the clock, or empty the bucket. Most universal gages have an inspection door large enough to provide access to the clock and chart. on gages with inspection doors too small for this, you can remove the receiver (top) and outer shield to gain access. 2.2.4.3 PREPARATION OF CHARTS Enter the following information in the spaces provided on the chart before putting the chart on the cylinder: a) Station name as specified by the NwS representative. b) Date and local time, to the nearest minute, that the pen will be placed on the new chart. Cross out P.M. when it is morning or A.M. when it is afternoon. When Daylight Saving Time is in use locally, enter I'D" following A.M. or P.M. For example, if the chart is changed in the morning, enter A.M.D. 2.2.4.4 B49L •LMNG AND REMOMG CHARTS charts should be changed on all of the following occasions. a) At least once a week. b) On the first day of each month. c) Within 24 hours after precipitation has ended. Do not change the chart during rain that is heavy enough to wet the trace and cause the ink to spread. Rather than change the chart, empty the bucket dosing heavy rain when the bucket may overflow or the capacity of the chart may be exceeded. When installing and removing charts, make a vertical mark about 1/4 inch long on the chart (trace) by gently touching the weighing mechanism which moves the Pen. This mark will serve as a time check for the office receiving the chart. If the pen is not making a trace on the chart, place a small dot on tine chart B7 PR=PITAn0K to mark the position of the pen. Draw a circle around the dot to identify it, and enter a note of explanation on the chart (e.g., "chart removed") . 2.2.4.5 CHANGING CHARM ON GAGES WITH LARGE INSPBC'ITION DOORS a) Open the inspection door and make a time check on the chart. b) Remove the pen from the chart by shifting the pen bar forward. c) Remove the receiver. d) Empty and replace the bucket, except when charged with antifreeze or when oil has been used to retard evaporation. e) Raise the outer shield (if so equipped) and rest it on the vertical guides. f) Grasp the cylinder at the top with one hand and, with the other, gently lift it over the spindle. g) Release the clip holding the chart. Avoid touching or storing the chart in a way that will cause the trace to be pared before it dries. h) Wind the clock. Caution: the clock may stop if wound too tightly. i) Wrap the new chart around the clock cylinder so the time reads left to riot, and so the chart fits smoothly and snugly on the clock cylinder. The chart base must uniformly contact the flange or cylinder. j. Replace the clip. Check to be sure that corresponding ends of each "inch" line coincide where they meet. The exposed end of the chart must extend 1/4 inch to the right of the clip. k. Replace the cylinder. Lower it gently over the spindle until the gears rash. I. Re-ink the pen. Return it almost to the surface of the chart. Make sure it reads within .025 inch of the last reading on the previous chart. It should read zero, however, if you have emptied the bucket, unless the NWS representative specified some other value. m. With the pen almost touching the chart, turn the cylinder until it reads three hours fast, then turn it back so it reads the correct time. Be sure the time is correctly written on the chart. n. Return the pelt to the chart. 'Ruch the weighing mechanism to make a vertical time check on the chart. Replace the shield and receiver. B8 PRECIPITATION 2.2.4.6 CHANGING CSNRTS ON GAGES WrM SHALL INSPEMON DOORS Use the following method on gages having small inspection doors. a) Remove the receiver and shield (exhibit 2.6) . b) Make a time check or identify the pen position on the chart by touching the weighing mechandsm. C) Shift the pen bar forward and lift the pen from the chart. d) EYpty and replace the bucket, except when charged with antifreeze. e) Grasp the chart cylinder at the top with one band, and with the other, gently lift it over the spindle. Relea--,-- the clip holding the chart, taking care not to smear the ink. f) Wind the clock. Wrap the new chart around the clock cylinder so the time reads from left to right, and so the chart fits smoothly and snugly. The chart base must uniformly contact the flange of the cylinder. g) Replace the clip. Check to be sure that corresponding ends of each "inch" line on the charts c0incide. The exposed end of the chart must extend 1f4 inch to the right of the clip. h) Replace the cylinder. Laren it gently over the spindle until the gears mesh. i) Re-ink the pen and return it almost to the surface of the chart. Note the amount the pen indicates on the chart. It should indicate the same value (within .025 inch) as before the chart was clanged. It should read zero if the bucket was enptied unless the NWS representative has specified that it read some other value at the time of the last calibration. i j) Return the pen to the chart. Touch the weighing mechanism to make a vertical time check on the chart. k) Replace the shield and receiver. 2.2.4.7 CCMPTZ= THE CRAMS After renwing the chart from the gage, enter the follawing. a) The local tix* and date of rWMal, as in section 2.2.4.3.b. b) An arrow 4) with the word "on" at the place the timecheck was made when the chart was installed. B9