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HomeMy WebLinkAbout735 RESOLUTION NO. .�� A RESOLUTION of the City of Kent, Wash- ington, adopting as City Policy the plans , procedures and objectives of Comprehensive Water Report of March 27 , 1972. WHEREAS, Hill, Ingman, Chase, Consulting Engineers , have prepared a Comprehensive Plan for the Water Department of the City of Kent, said Plan being promulgated March 27, 1972, and WHEREAS, said Comprehensive Plan provides for an orderly expansion and improvement of the plants and facilities of the Water Department of the City of Kent, NOW, THEREFORE THE CITY COUNCIL OF THE CITY OF KENT, WASHINGTON, DO HEREBY RESOLVE AS FOLLOWS: Section 1. The Comprehensive Plan for the Water De- partment of the City of Kent prepared and promulgated by Hill, Ingman, Chase, Consulting Engineers , March 27 , 1972, be and the same hereby is adopted as official policy of the City of Kent. Section 2. The City Council reserves the right to establish its own order of priority which may or may not be the same as those suggested in the Comprehensive Plan. PASSED by the City Council at a regular meeting this 16th day of October, 1972. ISABEL HOGA , MAYO ATTEST: Marie Jensen, ty Clerk AP R VED AS TO FORM: I� Y��Vk Donald E. Mirk, C71ty Attorney I hereby certify that this is a true copy of Resolution No.-._"73 , passed by the City Council of the City of Kent, Washington, the L day of October, 1972. (SEAL) MARIE JENS N, City Cle city for other wells in the area is less than 5 gpm per foot of draw- down. One difficulty with any proposed extensive development from this well would be the possible interference with other wells in the area. Prolonged withdrawal of 1500 gpm or more at this locality would undoubtedly lower water levels in surrounding areas to a point where other well owners would allege that they were damaged. The Wilson Well is 6-inches in diameter and if a large quantity of water were to be taken from this well for municipal supply, it would mean either drilling of a new well of sufficient diameter to permit installing the necessary pumping equipment, or construc- ting a surface basin or reservoir into which the present well could flow and the water then repumped into the distribution system. O' Brien Well The O'Brien Well, drilled to a total depth of 170 feet, is loca- ted in the Southeast 1/4 of the Southwest 1/4 of Section 7 , Town- ship 22 North, Range 5 East, W.M. This well formerly owned by the O'Brien Water Users Association is now owned by the City of Kent. The well when drilled, had a static water level of 38 feet above land surface and had an artesian flow of 60 gpm. A pumping test of 4 hours duration showed a yield of 100 gpm with the pump- ing level 18 feet below land surface or a specific capacity of ap- proximately 2 gpm per foot of drawdown. The well produces from thin layers of water bearing sand or sand and gravel below a depth of 150 feet. The specific capacity of the well would indicate that with a t deeper pump setting it should be possible to pump as much as 300 gpm from this well . In order to pump this higher rate, however, it might be necessary to re-drill the well, or to in some way, modify the present construction such as by installation of a well screen. The well is cased to 150 feet with open hole from 150 to 170 feet and pumping at high rates from the open hole might result in sand being pumped from the well. Deeper drilling at this location should encounter additional water-bearing sands and gravels, possibly similar to those encoun- tered at the Wilson Well. Green River Valley Near Auburn Alluvial deposits of permeable sand and gravel in the Green River Valley, near Auburn, offer a potential for groundwater de- velopment. A test drilling program was carried on in 1957 by the Ranney Method Western Corporation to determine the feasibility of installing a Ranney-type collector for groundwater development. 47 Test holes located within three miles of Kent, to the south, encoun- ter primarily very fine grained alluvial materials and groundwater that was of poor quality (high in dissolved iron) . Two test holes (Nos. 9 and 10) were then drilled approximately one mile northeast of Auburn and good water bearing sands and gravels were found im- mediately adjacent to the Green River to depths of more than 50 feet. A pumping test was conducted on test hole 10 with a discharge rate of 600 gpm (0. 75 mgd) . The water was of good quality with only 0. 06 ppm iron after pumping. It was tentatively concluded by the Ranney Corporation that a collector with a capacity of 10 mgd could be constructed at this locality although additional test drilling and pumping would be required for final design. The test drilling also indicates that these alluvial deposits would be suitable for development of rela- tively high capacity conventional vertical wells . It seems possible that as much as 1 1/2 to 2 million gallons per day might be devel- oped per well in this general area. S. 208th Street Near 94th Ave. South This location is less than one mile east of the Wilson Well, but at a land surface elevation at least 200 feet higher than the Wilson Well. It is anticipated that water-bearing sands and gravels would be encountered in drilling at this reservoir site, but it would probably require a well 300 to 500 feet deep to produce signifi- cant quantities of water for municipal use. Test drilling would be required in advance of any proposed development to further evaluate the thickness and character of water-bearing materials and the quality of water, as well as to estimate the potential interference with surrounding groundwater developments that might develop as a result of obtaining large quantities of water for the city at this location. i Covington Area i The Covington area is a short distance southwest of the Arm- strong Springs area previously discussed and lies within the aban- doned melt-water channel that extends southwesterly from near Maple Valley. A well drilled for the Covington sub-station of the Bonneville Power Administration, to a total depth of 106 feet, yielded 250 gpm with only 4 feet of drawdown. Water was developed in a thin zone of very permeable water-bearing sand and gravel near the bottom of the well. Based upon the results of the drilling at the BPA location, it 48 pumping capacity of 5400 gpm or about 7 .7 million gallons per day. It is believed that the maximum potential of the Clark Springs site has been developed with the recent drilling of the three wells . ` The water is of good quality and the wells, as constructed, should have a useful life of from 25 to 40 years. At such time as the wells might need replacement, substitute wells could be drilled in the immediate vicinity upon land owned by the city. Icy Creek Area The Icy Creek area is located approximately 11 miles east and 7 miles south of Kent. Icy Creek is a spring-fed stream origina- ting in the Southwest 1/4 of Section 30, Township 21 North, Range 7 East, W.M. Groundwater issues from ice-contact deposits surroun- ded till which is primarily clay. cted by gl acial In 1968 , a 6-inch test well was drilled to a depth of 215 feet and except for a little dry sand and gravel at shallow depth, all of the drilling was in impermeable clay. The total flow in Icy b represents essentially all of the groundwater avail- able from that immediate area -- with a minimum flow recorded in illon September 1967 of only 1.4 cubic feet per sect®ad gallons per day. Although ualoty,m heiperme- Althou h the water i g q � able sands and gravels appear to be of limited extent and there would be insufficient water available to supply any large amount for municipal use. It is estimated that the maximum available from the area would probably not exceed 3 million gallons per day and during periods of peak requirement in summer months the maximum available might be as low as 1 to 1 1/2 million gallons per day. Because of the potentially limited supply of groundwater, com- bined with the distance from the city and the cost of providing transmission pipelines, it is not considered that this area offers E any significant potential for municipal water-supply development. The Icy Creek area and an evaluation of its potential was discussed in more detail in Anderson & Kelly's report of May 1968 , "Water Supply Evaluation, Icy Creek Area, City of Kent, Washington" . Armstrong Springs The Armstrong Spring area is located about 6 miles east of Kent, adjacent to Highway 5A, in the Northeast 1/4 of Section 36 , Township 22 North, Range 5 East, W.M. The area lies along the surface depression channel trending northeast-southwest, which probably is an abandoned meltwater channel underlain by advance outwash deposits of Vashon age. Sev- eral small springs issue along the slope of the area bordering the 45 channel of Jenkins Creek. There has been no groundwater development at this locality but it appears to offer a potential for ultimate development for as much as 2 to 3 mgd or more. The groundwater should be of sat- isfactory quality although there be some peat deposits encoun- tered which might cause problems with iron or manganese in the water. It is probably, however, that proper well design and con- struction could produce water of suitable quality. Test or exploratory drilling, and possibly some pumping tests, would be required to evaluate the thickness and character of water- bearing materials underlying the site as well as to evaluate the maximum potential for future development. Briscoe Springs Briscoe Springs lie east of Angle Lake near the northwest corner of Section 2 , Township 22 North, Range 4 East, W.M. The springs issue from sands and gravels in the glacial drift along the western slope bordering the Duwamish Valley. The springs do not furnish a large amount of water and they have been developed by construction of a concrete surface reser- voir so that water from the springs could be collected and supplied to the Briscoe School lying to the east. It does not appear that the quantity available at this local- ity would be significant from a standpoint of augmenting the muni- cipal supply for the City of Kent. In all probability, the steep surface slope intersecting the water-bearing sands and gravels has drained the aquifer sufficiently so that no significant enlarge- ment of the present supply could be made economically. Wilson Well The Wilson Well is located in the Southwest corner of Section 6, Township 22 North, Range 5 East, W.M. , along 208th Street. This flowing artesian well was drilled in 1955 to a depth of approximately 207 feet. When the total depth of the well was reached it started to flow at a rate estimated in excess of 1600 gpm (2 million gallons per day) . The water is of suitable quality for municipal use with only a slight hydrogen sulfide odor noticed in the field and with a total hardness of approximately 85 parts per million. The Wilson Well, probably producing from permeable zones of the Salmon Springs drift, is unusual in that it has a much higher specific capacity and yield than other wells in the immediate vicin- ity. At the Wilson Well the specific capacity appears to be not less than 20 gpm per foot of drawdown, whereas the typical specific capa- 46 is estimated that individual wells with a capacity of 1 1/2 to 2 million gallons per day might be constructed. This would probably be true not only in the immediate vicinity of Covington, but also in the Armstrong Springs area .and even farther to the northeast where these same permeable sands and gravels could be expected. r Wells drilled in this area would probably not have to exceed 150 feet in total depth. East Hill Water Company Two wells owned by the City of Kent, and originally drilled for the East Hill Water Company, are located approximately two miles east of Kent in Section 29 , Township 22 North , Range 5 East, W.M. Well No. 1 was drilled to a depth of 268 feet and produced 45 gpm with 25 feet of drawdown. Well No. 2 was drilled to a total depth of 286 feet and produced 170 gpm with 50 feet of draw- down. In both cases, the specific capacities are generally from 2 to 3 gpm per foot of drawdown. Although deeper drilling might encounter more permeable zones , the tests on the wells in their present condition do not indicate that large capacity wells would be potentially feasible at this location. Individual wells to depths of 300 feet would probably not be capable of furnishing more than 1/2 million gallons per day each. i City of Seattle Transmission Lines The City of Seattle provides a ready source of supply through a series of transmission mains and reservoirs either existing or proposed. As shown on Figure 6-1 , quite an extensive system of mains and reservoirs is planned for the Kent area. The City of Seattle has a 42,1 transmission main scheduled for 1973 construction, which would come from Lake Youngs , cross the valley floor and terminate at a reservoir on West Hill. It is proposed that this line would. be interconnected at some later date , to the City of Seattle'.s existing transmission main on S. E. 160th Street. In addition to these mains , the City of Seattle has two large mains planned for 1988 and 1998, which would come from a new im- poundment on the Cedar River, east of Landsberg. Seattle also has several large storage reservoirs planned and these are indicated on Figure 6-1. The Seattle Transmission Mains as proposed, can supply all the water necessary within the study area and for all purposes , can be considered an unlimited source. Any purchase of Seattle water would have to be made in accordance with Seattle's requirements , the most significant of which does not allow any other source to supply the 49 rye > -- - --- - •- f f r i �a,\ q %1 fr f�r�o fr 1 If 2MIKil- A. 2' N r J���iM1 � , Yyyy:Il�ee i ✓ 11IT 147,11 IK Q , Des Moines•' Mid s f F f16 +, • 516 LDERNES !l l ao 9 4 " :ssna srsr ,�, .3: .sl a. a I ♦� !y =i . i 23. o cam..IT )` ♦� CIO �t �.. ,♦� ! ♦ zs ......:.. 'f-t iiEiiiiiiEEiiiiiir'j ' Clark Springs q f 1 �Ke t' Springs ■ A 13 41 o 71 \\ t Way / 1 7 al c , t ources sl Icy Creek 5 miles Figure 6-1 icilities lines WATER SOURCES it INCLUDING SEATTLE SUPPLY LINES CHAPTER VII COMPREHENSIVE SOURCE PLANS 1. 6 CHAPTER VII COMPREHENSIVE SOURCE PLA14S The preceding chapters of this report have dealt with popu- lation projections and water usage which are based on many factors which affect the growth of an area. In Chapter VI the potential sources of new water were presented and along with this , the City 's existing sources were discussed and evaluated. In this chapter alternate development plans for source expan- sion are discussed, along with the improvements necessary to de- velop the source, and make it available to the City of Kent. Water source planning is generally developed on the basis of serving a specific service area. In the absence of a specific service area, one must be developed based on source availability and established design criteria. The City of Kent does not have available enough groundwater to serve the entire study area, and the purchase of Seattle water for some part of the study area is a necessity. With this in mind, studies were made of several alternatives, with respect to source, development, transmission and service area. These were evaluated on the basis of cost comparisons to determine which would be the most desirable. I Based on the foregoing studies , two general source plans are presented herein and have been designated as Plan A and Plan B. PLAN A - Under Plan A, Kent would immediately begin service to its north industrial area with wholesale water purchased from Seattle, and serve all of the Valley system and West Hill with Seattle water after 1973. The eastern portions of the study area would be served with Kent water until Seattle water is available in 1980 - 1985 . After this time, Kent water would serve their intermediate and high level pressure zones easterly to Water Dis- trict No. 111 service area on approximately 124th Avenue S.E. These zones could also be served by Seattle water after 1973, if so desired. PLAN B - Under Plan B, Kent would continue to develop its own sources, until no further ground water supply can be economically developed, at which time the eastern portion of the study area would purchase wholesale water from the City of Seattle and Kent would serve the balance of the study area with their own sources. t 53 same area. This would not mean that Kent would not have other sources, but these sources could not be "mixed" and would have to be isolated. s for Seattle water is shown in Table 7-40 A tabulation of rate R c• 50 i c r P TABLE 7 -4 SEATTLE WATER RATES* 700 cubic feet or less . . . . . . . . . . . . . . . $1. 10 Each separate building or premises in addition to the first or principal building or premises sup- plied through the same service connection. 700 cubic feet or less . . . . . . . . . . . . . . . $1. 10 Provided, that the terms "separate building or premises" shall not apply to trailer parks or trailer courts , which shall be governed as to water rates by the number and size of services , and quantity of water used, under the previous schedule. Each 100 cubic feet in excess of the first 7U0 cubic feet, except as hereinafter provided . . . . . . 11 Each 100 cubic feet, exceeding 200 ,000 cubic feet or more used in one month, except as here- inabove provided . . . . . . . . . . . . . . . . . . .09 Each 100 cubic feet in excess of the first 30,000 cubic feet where 80% of the water is used for manu- facturing and industrial purposes, golf courses and cemetaries . . . . . . . . . . . . . . . . . . . .08 *The City of Seattle has hired a consulting engineering firm to study and modernize their rate structure . It will be approximately 1 year before the results are available. The unit cost of water for Plan A is shown in Table 7-5 . TABLE 7 -5 UNIT COST OF WATER - PLAN A Seattle Water 12 .2G/100 cubic feet Based on Table 7-4 Dent Springs 15 . 2�/100 cubic feet Armstrong Springs The cost per cubic foot as shown in Table 7-5 is based on the projected cost estimates contained herein and the current Seattle Water Rate. 61 4 MARE ,1EIVSEN CITY OFKENT i d�f]Ga KING COUNTY, WASHINGTON ( d nMM COMPREHENSIVE CATER REPORT PHASE I - WATER SOURCES PHASE II - STORAGE, TRANSMISSION AND DISTRIBUTION 4 1972 HILL, INGIVIAN, CHASE & CO. Consulting Engineers and Analysts . . . since 1891 N rig A URS Systems Affiliate 1 V � CITY OF KENT COMPREHENSIVE WATER REPORT I ` PHASE I - WATER SOURCES PHASE II - STORAGE, TRANSMISSION & DISTRIBUTION Prepared by HILL, INGMAN, CHASE & CO. Consulting Engineers 2909 Third Avenue Seattle, Washington 98121 I I G I HILL, INGMAN,CHASE do CO. Consulting Engineers and Analysts...since 1891 v 2909 Third Avenue,Seattle,Washington 98121 (206) 623-6000 March 27, 1972 Honorable Mayor and City Council City of Kent Kent, Washington 98031 Gentlemen: We have completed the necessary engineering studies and are submitting a Comprehensive Water Report, describing improve- ments to and expansion of the water sources , storage reservoirs and transmission and distribution facilities to be undertaken by the City of Kent. This study includes Phase I , Water Sources , which was presented separately in November 1968 and Phase II , Storage , Transmission and Distribution, which was recently completed. Material con- tained in both Phase I and Phase II of this report has been summarized in Chapter 2 . Recommendations are also presented for your consideration in this Chapter. Throughout the course of our study, the cooperation of all members of the administrative, engineering and operational staff with whom we worked, was exceptional. Acknowledgment is also due for the dedication of those individuals most directly concerned with the function of the water system. We appreciate this opportunity to be of additional service to the City of Kent in the development of a long-range water service plan. Should you desire additional information concerning this report, we would be pleased to meet with you at your convenience. Very ruly yours, William J. Chase, P.E. President ��_ - & ,'q Z 4x E. Walter G. Ramsey, P. Vice President WJC/WGR/tg P CITY OF KENT, WASHINGTON COMPREHENSIVE WATER REPORT Isabel Hogan, Mayor Councilmen Peter Baffaro Robert Kitto James Jackson Charles Martell Gary Just Jeanne Masters William Elliott Administration Joseph Street - Administrator Glen Sherwood - City Engineer Joseph Engeln - Assistant Engineer Don Mirk - Attorney Kenneth Evenson - Water Superintendent James Harris - Planning Director Margaret Drotz - Treasurer Marie Jensen - City Clerk Project Staff Hill, Ingman, Chase & Co. William Chase Gerald Schlagel Walter Ramsey Harold Chenoweth James Leet Joyce Haney Steve Barker Anderson & Kelly, Consulting Geologists Keith Anderson Jack Kelly ACKNOWLEDGMENTS i We wish to express our appreciation for the capable assis- tance and find cooperation extended by the following individuals and agencies : II. DeWayne Kreager - Consultant to Industry Richard Fowler - Planning Consultant CITY OF SEATTLE WATER DEPARTMENT Harry L. Pratt - Principal Engineer Al Chuang - Assistant Engineer KING COUNTY PLANNING DEPARTMENT Edward B. Sand - Director of Planning STATE DEPARTMENT OF SOCIAL & HEALTH SERVICES - DIVISION OF HEALTH Wilson F. Bow - Supervising Engineer A. G. Koch - District Engineer DEPARTMENT OF HOUSING & URBAN DEVELOPMENT Lynn Stowell - Program Manager Louise Steele - Community Development Representative TABLE OF CONTENTS a PAGE CHAPTER I - INTRODUCTION 1 ' Authorization Purpose Objectives Study Area Previous Studies organization of the Report CHAPTER II - SUMMARY AND RECOMMENDATIONS 6 Summary Population and Water Usage Water Resources Comprehensive Source Plan Financial Assistance Programs Design Criteria Existing Water System and Topographic Studies Computer Analysis of Existing System Comprehensive Plan and Cost Estimates Recommendations Phase I Phase II PHASE I CHAPTER III - INTRODUCTION 15 Authorization Purpose Objectives Study Area Previous Studies History of Water System Improvements ` CHAPTER IV - POPULATION 22 Factors Affecting Growth Sources of Population Data Population Projection - Study Area Service Area Population CHAPTER V - WATER USAGE 29 Water Consumption Domestic Consumption Commercial and Industrial Consumption Fire Demand Design Quantities r Table of Contents (Continued) Y PAGE CHAPTER VI - WATER RESOURCES 39 Geology Occurrence of Groundwater Principal Aquifers Recharge Quality of Water Potential Development Areas Kent Springs (Elevation 485) Clark Springs (Elevation 560) Icy Creek Area Armstrong Springs Briscoe Springs Wilson Well O'Brien Well Green River Valley near Auburn South 208th Street near 94th Avenue South Covington Area East Hill Water Company City of Seattle Transmission Lines CHAPTER VII - COMPREHENSIVE SOURCE PLANS 52 Plan A Plan B Comparison Criteria for Alternate Plans Plan A - Development Plan B - Development Cost Comparison of Alternate Plans Pollution Protection Watershed Requirements Capitalized Cost of Improvements CHAPTER VII-A - SUPPLEMENTARY SOURCE PLANS 65 CHAPTER VIII - FEDERAL - STATE - FINANCIAL 68 ASSISTANCE PROGRAMS Bureau of Outdoor Recreation, Department of Interior Washington State Inter-Agency Committee for Outdoor Recreation Department of Housing and Urban Development Economic Development Administration Table of Contents (Continued) PHASE II PAGE Chapter IX. Design Criteria 72 General Residential Industrial Commercial Schools Apartments Flow Rate Summary Fire Demand Friction Factor Pipelines Reservoirs Chapter X Existing Water System 79 General East Hill System (Elevation 590) East Hill Intermediate System (Elevation 485) Low Level System (Elevation 240) ,Test Hill Intermediate (Elevation 354 .5) West Hill System (Elevation 529) Chapter XI Topographic Studies 93 General East Hill System East Hill Intermediate System 416 Foot Storage Level Low Level System West Hill Intermediate System West Hill System Chapter XII Computer Analysis of Existing Systems 99 General East Hill System East Hill Intermediate System Low Level System West Hill Intermediate System West Hill System vi li r :able of Contents (Continued) PAGE Chapter YIII Comprehensive Plan and Cost Estimates 105 East Hill System East Hill Intermediate System Low Level System West Hill Intermediate System West Hill System Cost Estimates Construction Costs Project Costs Appendix 123 City of Seattle - Water Rates to Purveyors Water Quality Analyses INDEX OF FIGURES Figure Page 1-1 Study Area - Phase II . . . . . . . . . . . . . 5 3-1 Study Area Boundry - Phase I . . . . . . . . . 21 4-1 Population Trends . . . . . . . . . . . . . . . 27 4-2 Neighborhood Areas. . . . . . . . . . . . . . . 28 5-1 Kent Average Annual Water Usage (1967) . 35 5-2 Kent Average Annual Water Usage (1954) . . . . . 36 5-3 Study Area Projected Water Usage . 37 5-4 Service Area Projected Water Usage . . . . . . 38 6-1 Water Sources . . . . . . . . . . . . . . . . . 51 7-1 Plan A Service Area - Supply vs Demand . . . . 63 7-2 Plan B Service Area - Supply vs Demand . . . . 64 10-1 Existing System - West Hill . . . . . . . . . 88 10-2 Existing System - North . . . . . . . . . . . . 89 10-3 Existing System - Central . . . . . . . . . . . 90 10-4 Existing System - South . . . . . . . . . . . 91 10-5 Existing System - East Hill . . . . . . . . . . 92 11-1 Service Levels . . . . . . . . . . . . . . . . 95 13-1 Comprehensive Plan - West Hill . . . . 118 13-2 Comprehensive Plan - North . . . . . . . . 119 13-3 Comprehensive Plan - Central . . . . . . . . . 120 13-4 Comprehensive Plan - South . . . . . . . . . . 121 13-5 Comprehensive Plan - East Hill . . . . . . . . 122 INDEX OF TABLES r Table Page 4-1 Study Area Population Estimate . . . . . . . . 26 5-1 Commercial Water Consumption . . . . . . . . . 31 5-2 Industrial Water Consumption . . . . . . . . . 31 5-3 National Board of Fire Underwriters Required Fire Flow . . . . . . . . . . . . . . 32 7-1 Plan A - Project Costs . . . . . . . . . . . . 58 7-2 Plan B - Project Costs . . . . . . . . . . . . 58 7-3 Estimated Life of Improvement . . . . . . . . 60 7-4 Seattle Water Rates . . . . . . . . . . . . . 61 7-5 Unit Cost of Water - Plan A . . . . . . . . . 61 7-6 Unit Cost of Water - Plan B . . . . . . . . . 62 13-1 Stage One Project Costs . . . . . . . . . . . 111 13-2 Project Cost Estimates for Comprehensive Plan 116 CHAPTER I INTRODUCTION CHAPTER I INTRODUCTION This report presents the results of studies undertaken for the purpose of developing a general plan for the continued or- derly growth and development of the water system for the City of Kent, in King County, Washington. In the development of this report, population projections and distribution,, water use projections and source, land use, and utilization of existing facilities were evaluated in arriving at the recommendations and conclusions herein set forth. Phase I , Water Sources, pre- sented separately in 1968 and Phase II , Storage, Transmission, and Distribution are included in this report. This chapter in- cludes the introduction to Phase II of this study. The intro- duction to Phase I is included in Chapter III. AUTHORIZATION The City of Kent, recognizing the need for ample supplies of high quality water, authorized Hill, Ingman, Chase & Co. to proceed with Phase I of a comprehensive water study on September 18 , 1967. This phase of the report was completed and presented in the late fall of 1968. Under the agreement made and entered into on July 30 , 1969 , authorization was given by the City of Kent to proceed with the development of Phase II of the comprehensive water study. This J f C R1 } Kent Valley 2 phase of the study, consisting of an analysis of transmission, distribution and storage facilities, service levels , and speci- fic economic recommendations , has been completed in accordance with the terms of this agreement. PURPOSE The purpose of Phase II of this study is to develop a com- prehensive long-range plan for the continued orderly development of the transmission, storage and distribution facilities for the City of Kent. The sources of water supply presented in Phase I of the comprehensive study, have been considered in Phase II as they will influence the location of necessary improvements to the storage and distribution facilities . OBJECTIVES The objectives for Phase II of the engineering study are as follows : 1. The establishment of basic design criteria for the City and study area. 2. Investigation of the existing water system and the preparation of maps showing these facilities. 3. Topographic studies of the comprehensive area and the determination of the required service levels. I 4. A computer analysis of the existing water system and the proposed distribution, storage and trans- mission facilities. 5. Preparation of a comprehensive plan for the study area setting forth the location and size of major. distribution lines, transmission mains, and storage units , together with the necessary upgrading of the existing system and the precedence of these improve- ments. 6. Preparation of cost estimates on all portions of the { comprehensive plan. 7. Preparation of a comprehensive plan report covering Phase I and Phase II. 8. Preparation of maps showing the proposed improvements. STUDY AREA The area to be studied in this Phase, as set forth in the agreement, extends generally from Interstate 5 On the west to 132nd Avenue Southeast on the east, and from South 288th Street 3 on the South to South 180th Street on the north. The boundaries of this study area are shown on Figure No. 1-1. The total area within these boundaries is approximately 39 square miles. Figure No. 1-1 also shows the boundaries of the City of Kent and the boundaries of adjacent municipalities. Although outside of the study area, the effects of water districts which obtain their supply from the City of Kent at the present time were considered. PREVIOUS STUDIES In addition to the studies mentioned in the Phase I report, the following recent studies have been reviewed and incorporated in the Phase II Plan. 1. "Investigation of Groundwater Supplies" , by Anderson and Kelly , the City' s Consulting Geologist, in October 1969 , and Addendum Report. 2. The Water Department of the City of Seattle has prepared a report entitled, "Analysis of Water System Costs and Rates to Water Purveyors" , published in February 1970. ORGANIZATION OF THE REPORT This report consists of two phases which have been combined and bound into one volume. Phase I is the result of a 1968 study of a general plan and development of water sources. This is presented in Chapters III through VIII. Phase II is an analysis of and planning for transmission, storage and major distribution facilities. This material is contained in Chapter I and Chapters IX through XIII. Chapter II is an overview of the entire report and recommen- dations for , implementation. 4 i 1 . i I I CHAPTER II SUMMARY AND RECOMMENDATIONS F i r� CHAPTER II SUMMARY AND RECOMMENDATIONS GENERAL The purpose of this chapter is to present a condensed review, summarizing the principal features of this Engineering Report. Specific recommendations are presented in this chapter based on findings and conclusions reached during the course of the study. This report consists of two separate studies that when merged as one, compose the comprehensive water plan for the City of Kent. The two studies are: Phase I - Water Sources, which was presented to the City in Novem- ber 1968. Phase II - Storage, Transmission and Distribution Facilities. The summary and recommendations of Phase I have been updated to reflect subsequent investigations and current planning. This material is contained in this chapter, as well as the summary for Phase II. Recommendations concerned with both phases of the study are also set forth in this chapter. Population and Water Usage The City of Kent and the study area as a whole have, in general, experienced a rapid rate of growth. Recent declines, however, in aerospace employment and the general downward trend of the economy have slowed the growth rate. The population of the study area as outlined in Phase I , is expected .to more than triple during the study period, and as the population grows, so do the water requirements. Projections indi- cate that by the year 2000, the Phase I Study 'area will have a popu- lation of over 166, 000 people with water requirements exceeding 56 million gallons on the peak days. In preparing to meet these requirements , the City' s existing sources and proposed new sources were investigated to determine the amount of water which the City might reasonably expect to develop. In addition, the City of Seattle 's water supply was investigated as a source. Water Resources There appear to be several localities in the vicinity of Kent that would have the possibility of providing groundwater for muni- cipal use. The areas considered to be of best potential are Kent Springs and Armstrong Springs. 7 During the summer of 1969 , a test drilling program was under- taken in the Kent Springs area by the City. The results of these tests indicated a potential supply of approximately 10 mgd could be developed from this source. This quantity includes the present pro- duction of approximately 3 mgd from the existing infiltration gallery. Tests conducted at the Armstrong Springs site indicated a po- tential supply of approximately 2 mgd could be developed . The detailed information on the test drilling program is con- tained in a report on the investigation of groundwater supplies pre- pared for the City in 1969 by Anderson & Kelly, Geological Consul- tants . Although the Covington area, the Wilson well and drilled wells in the Green River Valley near Auburn were considered as potential sources in the study of Water Resources, subsequent investigations and study indicate that these sources do not warrant further consi- deration at this time. Comprehensive Source Plans Two plans were developed for the Phase I study. These plans are presented in Chapter VII as Plan A and Plan B, and reviewed as to current planning in Chapter VII A. Plan A provides that the City continue to use their existing sources of water and as the need arises, utilize Seattle water. In the future, existing Kent sources would continue to be used and expanded and one new Kent source developed. The area which would be served most effectively and logically with Seattle water would be the West Hill System. This supply will be available upon the installation by the City of Seattle of a trans- mission main, presently being planned which will extend from the Lake Youngs area to the West Hill . As the demand for water increases , a portion of the low level system can be isolated for service from the City of Seattle. At this point in time, Kent water sources will supply the reamining portions of the Low Level System, the areas immediately adjacent to the City on the east in the Intermediate and East Hill pressure zones, Water District' s No. 111 and No. 105 (stand-by basis only) and other areas in the east portion of the Study Area. After this time, the City will then continue to serve their Intermediate and East Hill pressure zones to approximately 124th Avenue S. E. This is a realistic plan and can be implemented quite easily, providing the City of Kent with large quantities of water. Plan A also meets the general concept as established for regional planning and provides the added advantage of having , flexibility through the availability of large quantities of water. This feature is expec- ially desirable for a community when formulating long-range water supply plans . 8 Ir II Plan A has the added advantage of providing the City at any time, with the option of developing an additional supply from one of the previously mentioned sources , or supplementing their pre- sent supply with Seattle water. ! The following tabulation lists the total quantities of water available from present sources, and the quantity available through i full development of Kent Springs and Armstrong Springs. GROUND WATER SOURCES Source Capacity MGD Clark Springs (Present fully developed capacity) 7.7 Kent Springs (Total Estimated Capacity) (Present Capacity approx. 3. 0 mgd) 10. 0 Armstrong Springs (Total Estimated Capacity) 2.0 Total 19. 7 mgd Plan B, formulated plans for utilizing the City of Kent's own sources of supply through the development of groundwater resources. The City of Kent would continue to serve all areas of the City in- cluding Water Districts No. 111 and stand-by service for No. 105. The water demands of this area would be met by development of exist- ing and potential groundwater sources. After 1981, Water District No. 111 and No. 105, together with eastern portions of the study area would be served by City of Seattle water and Kent would con- tinue to serve the remainder of the study area lying westerly of 124th Ave. S. E. from their own sources. Plan A and Plan B were compared on the basis of total capital outlay required to implement them and Plan A was a more advantag- eous plan since the capital outlay was less than Plan B. Plan A also has the additional benefit of no large capital expenditures • for approximately eight years, in comparison to Plan b which requires significant initial capital outlay. The alternate plans were then compared as to the cost per unit of water. On this basis, both plans are in the same range of estimated unit water costs. Financial Assistance Programs The State and Federal governments have a number of Financial assistance programs to aid in the development and construction of water facilities. The program that appears most applicable to waterworks projects is the Department of Housing and Urban Develop- ment Act, which provides grants not to exceed 50 percent of the cost of construction. Design Criteria Design criteria were developed in Phase II of the study, and used as a guide for the planning of new facilities as well as for 9 evaluating existing facilities . Domestic water usage rates were determined for the various ser- vice areas including residential, commercial and industrial, as well as for multiple residences and for schools. Fire flow requirements were also developed for these areas and maximum flow requirements were determined. The factors developed are as follows: Land Use Flow Rate in G.P.M./Ac. Residential 3. 5 Industrial 2. 0 Mercantile & Commercial 2. 5 Apartments 4 - 12 Schools 0.08-0 .145 GPM/Student Existing Water Systems and Topographic Studies The existing water system of the City of Kent provides service to an area of approximately 15 square miles through five different service levels. Water is also supplied to three water districts. Approximately 11 million gallons per day is presently available from the City' s two sources of water at, Clark Springs and Kent Springs. service Within the study area, there are five major se ice levels or pressure zone areas. These levels are as follows: Elevation above Sea Level Feet East Hill System 590 East Hill Intermediate System 485 Low Level System (Valley) 240 West Hill Intermediate System 354 . 5 West Hill System 529 Water is stored in eight storage reservoirs with a capacity of over 18 million gallons, including an additional reservoir with a capacity of 6 million gallons recently constructed. Distribution of water is through some 75 miles of pipeline rang- ing in size from 16 inches in diameter to 1 inch in diameter. Computer Analysis of Existing System The planning of new pipelines included in the comprehensive plan was based on the results of computer analyses of the existing system and projected growth estimates . Each separate portion of the entire system was analyzed for various operating conditions including deli- vering fire flows to critical areas . Analysis of portions of the system were also made using estimated future conditions. 10 Computer analysis indicated that adequate flows for domestic M usage can be delivered to all areas except a small area at the North end of the West Hill System. Construction of an elevated storage tank in this area will correct the pressure problem. Computer studies also reveal that the low level system, or valley system, presently has the capability of adequately supplying both domestic and fire flows. These studies show, however, that the East Hill System, East Hill Intermediate System, West Hill Inter- mediate System and West Hill System, generally cannot adequately supply both domestic and fire flows in certain critical locations, such as schools. These system deficiencies will be corrected by the installation of facilities as described as a part of the com- prehensive plan improvements . Comprehensive Plan and Cost Estimates The Comprehensive Water Plan developed in Phase II of this report includes transmission , distribution, and storage facilities . The transmission and distribution facilities are generally planned to provide for development based on population projections through the year 2000. Reservoir capacities are based on 1985 projections since these facilities are usually constructed on the basis of staged programs. Comprehensive plan improvements for additional water supply include connections to the City of Seattle proposed transmission pipeline to serve the West Hill areas and portions of the Valley System. Eventually, the Kent Springs source will be expanded, the Armstrong Springs source will be developed, and a new supply main constructed to bring water from these sources to the City. Water storage reservoirs with capacities totaling 8 . 5 million gallons are planned to provide additional storage for the East Hill, East Hill Intermediate and West Hill Systems. These reser- voirs will be supplied from pumping stations planned as a part of the improvements . A facility of interest will be a pumping sta- tion on the reservoir site at James Street and 98th Avenue S. This pumping station will consist of one structure containing the pump- ing equipment for providing water for . two different pressure level systems , thus keeping piping requirements to a minimum. Distribution pipelines are planned to provide increased service to areas presently served and to extend water service to areas not as yet developed. Major distribution pipelines planned include mains to improve the service to the Derbyshire area, the Scenic Hill School area, and industrial properties lying in the extreme north and south portions of the study area. Cost estimates, shown in Tables 13-1 and 13-2 , were prepared for all facilities included in the Comprehensive Plan. Table 13-1 includes project costs for Stage I improvements that are proposed for construction during the next five year period. A total of $2 ,630 ,600 was estimated for these costs . The total estimated project cost for all facilities outlined in the Comprehensive Plan is $9 ,015 ,700 including Stage I Projects . 11 RECOMMENDATIONS The following recommendations pertain to both Phase I and Phase II of the comprehensive report and have been combined for the purpose of an overview of the total water facilities program. On the basis of the information developed in this study and in consideration of the current planning and investigations under- taken subsequent to the presentation of Phase I, it is recommended that the City of Kent: (1) Consider the adoption of Plan A for the supply of water. This plan provides that the City continue to use their existing sources of water and as the need arises connect to Seattle' s proposed transmission line. In the future, additional Kent sources would be developed and used to supply the Eastern portions of the study area. (2) Study the outstanding bond ordinances, operating state- ments and capital improvement programs to determine an appropriate water rate structure. (3) Obtain groundwater rights from the Department of Water Resources, State of Washington, to appropriate public j groundwater in the amounts determined by the 1969 in- vestigation at Kent Springs and Armstrong Springs. I (4) Complete the necessary applications to obtain matching fund grants for the acquisition of additional water shed areas at Kent Springs . (5) Adopt the system of comprehensive water plan improvements as developed in this study and, update it as required to reflect changed conditions . (6) Submit copies of this study to regulatory agencies for approval of the comprehensive planning and as a step toward participation in grant programs . (7) Continue to coordinate with the City of Seattle as to the locations and design of future connection facilities to their planned transmission main. (8) Authorize preliminary planning to determine the system and financial feasibility, including the availability of grant funding, for construction of the following pro- jects of most urgent need. a. As part of the East Hill System, construct a 12-inch main along 116th Ave. S . E. from the Kent-Kangley Road to S . E. 280th St. to provide increased service and fire flow in the Derbyshire and Pine Tree Elemen- tary School areas - $105, 000 . 12 " b. Obtain the site for the future five million gallon standpipe to serve the East Hill System - $30, 000 . F. C. Construct a dual purpose pump station on existing City property near James St. and 98th Ave. S. for the purpose of supplying water to the East Hill In- termediate System and the East Hill System, from the existing 6 MG reservoir - $90 , 800 . d. Acquire the site for two standpipe reservoirs having a total capacity of 2 . 5 MG adjacent to 98th Ave. S. and S. of. S . E. 264th St. , extended. As the first stage of this storage requirement, construct a 1 MG standpipe reservoir that will serve the East Hill Intermediate System - $178, 600 . e. Install a 10 and 12-inch main along Woodland Way from Walnut St. to S . 264th St. to supply the pro- posed 1 MG standpipe reservoir and the Scenic Hill School - $55, 500 . f. Install an 18-inch main on City property and 98th Ave. S . from the proposed pump station to James St. to supply the East Hill System - $17 , 000. g . Construct a pressure reducing valve station along Alvord Ave. N. of Temperance Street to service the lower areas of .the Intermediate System - $7, 600 . h. Install an 8-inch main through the Canyon area, ap- proximately 450 feet East of E. Titus Street, from Smith Street to Kensington Avenue to improve service to Scenic Hill - $7 , 600 . i . Construct a meter station, pressure reducing valve station and connection to the proposed City of Seattle transmission main at S . 212th St. and 84th Ave. S. (East Valley Highway) - $31, 300 . j . Expansion to provide increased capacities of the two existing pumping stations supplying the West Hill System - $54 , 900. k. Construct a meter station, pressure reducing valve station and connection to the proposed City of Seattle' s transmission main crossing Kent-Des Moines Road - $29, 700 . 1 . Construct a 16-inch supply line on Kent-Des Moines Road from proposed City of Seattle pipeline to 48th Ave. S . (Reith Road) to supply the West Hill Systems - $59, 200 . 13 M. Obtain a site and construct a 1 MG standpipe reser- voir in the vicinity of 37th Ave. S . and S . 244th St. This reservoir will serve the West Hill System - $189 , 500 . n. Construct an 8 and 10-inch supply line for the West Hill elevated tank on Hampton Way and easement from the tank to Manchester Ave . - $9, 200 . o. Install chlorination facilities and structure at Kent Springs - $25, 900 . The above described projects comprise a total project cost of $960, 200. This study has determined that these improvements are required to meet existing deficiencies and improve the operation q g of the water system. The projects included are not arranged in order of precedence, but are all high in priority as determined in many conferences of the consultant and the administration staff of the City of Kent. I I 14 4 PHASE I Chapter III Introduction Chapter IV Population Chapter V Water Usage Chapter VI Water Resources Chapter VII Comprehensive Source Plans Chapter VII-A Supplementary Source Plans Chapter VIII Federal-State-Financial Assistance Programs 4 CHAPTER III INTRODUCTION CHAPTER III INTRODUCTION Phase I of this report presents the results of studies under- taken for the purpose of developing a general plan and program of water source development for the City of Kent in King County, Wash- ington. The findings, conclusions and recommendations contained herein, are concerned with projected population, water usage pro- jections and a study with recommendations for a program of source development and expansion. The City of Kent, adjacent areas and the Green River Valley considered as a whole, have experienced a period of rapid and ac- celerated growth. Today as never before, we are aware of the im- portance of water in this vicnity for the life and growth of muni-' cipalities. AUTHORIZATION 4, The City of Kent recognized the need for ample supplies of high quality water and authorized Hill, Ingman, Chase & Co. , to proceed with Phase I of a Comprehensive Water Study. This study has been completed in accordance with the terms of the contract for Engineer- ing Services by and between the City and the Engineers . Phase II of this study will consist of an analysis of transmission and stor- age facilities, service levels and specific economic recommendations. This study provides additional data and updated information to that contained in the City' s Engineering Report of 1955 . i j PURPOSE The purpose of this study is to develop a comprehensive long- range plan for the orderly development of water sources necessary to assure the City of Kent an adequate, high quality supply of water and presents recommendations herein. Transmission, storage facilities and distribution facilities are not a part of this plan and have been considered only to the extent which they might influ- ence location of the water source . OBJECTIVES The objectives for this Engineering Study were as follows: 1. A review and analysis of previous studies made by and for the City. 2. A projection of estimated population growth and distri- bution for the City and its immediate adjacent area. 16 3. A review of all watershed holdings by the City with recommendations. 4. An appraisal and study of economics and financial feasibility with estimated costs of obtaining water from the existing projected Seattle supply lines , to which Kent might connect. 5 . A review of the feasibility of establishing a supplemental water supply at the previously tested site on the Green River by means of specially designed underground collectors . 6. A review of the City Water Department' s potential boundaries based on the above population studies and trends which would provide maximum area coverage commensurate with good manage- ment and business practices. 7. A general plan and program of source development for the period of 1968 to 2000 with general details on location, size, type and estimated cost of water sources which may reasonably be needed during that period. E STUDY AREA The area to be studied was determined by giving consideration to the following items : Topography Existing and probable extensions of the city limits Present and future population Industrial growth potential In developing this comprehensive plan, political and municipal boundaries were not considered a limiting factor and the plans pre- sented include other district boundaries that were necessary to ob- tain the proper balance and relationship of facilities essential to sound water source planning. The study area is bounded on the west by Interstate 5 , on the north by the City of Renton, on the south by the City of Auburn and extends generally southeasterly past Lake Youngs to encompass Clark Springs. The boundaries of the study area are shown in Figure 3-1. The total area within these boundaries is approximately 44 ,500 acres or 70 square miles. Figure 3-1 also shows the boundaries of the City of Kent, adjacent cities and water districts both inside and outside of the study area. 17 SERVICE AREA The service area lies within the study area but its boundaries are somewhat more difficult to define. The present service area is comprised of many areas which are not always contiguous. The City of Kent presently serves the following areas: (1) The City of Kent (2) Water District 87 (3) Water District 111 (4) Water District 105 The City of Kent also serves some areas of the county which are not water districts, such as Park orchard, East Hill and Derby- shire areas. one of the objectives of this report, as stated above, is to review these areas in conjunction with the Water Departments potential boundaries. PREVIOUS STUDIES The following previous studies and reports have reviewed water source requirements in the Kent area to some degree. 1. Engineering Report for the City of Kent prepared by Hill Ingman, Consulting Engineers, 1955. 2. Forecast of water supply and demand through the year 2020 prepared by City of Seattle Water Department, March 1967. 3. Comprehensive Water Resource Study prepared by the State of Washington, January, 1967. 4. Several reports by Anderson & Kelly, the City's Consulting Geologist, prepared in 1962, 1963, 1967 and 1968 . 5. bong-range Water Supply Plan for Icing County by City of Seattle Water Department, October, 1966. The foregoing reports and their recommendations have been in- tegrated into the findings of this study. In addition to the above referenced reports, many reports have been prepared on population and many of the sites investigated have had previous reports prepared on them. All of these reports have been reviewed and are referenced in the appropriate chapter. 18 HISTORY OF WATER SYSTEM IMPROVEMENTS The City of Kent adopted a Comprehensive Water Plan in 1955, based on a study and report prepared by Hill & Ingman, Consulting Engineers and the following is a list of improvements which have been undertaken since that time. YEAR ITEM 1955 A Comprehensive Plan for water supply and distribution was adopted by the City of Kent. 1957 The Clark Springs water source was developed together with a transmission main from Clark Springs to Kent Springs and improvements consisting of a booster pump station was installed on the existing transmission main. East Hill Water System Improvements were made consisting of a booster pump station, transmission line and 125,000 gallon elevated storage tank near the intersection of South 240th Street and 98th Avenue South. Construction of the first North Industrial Water Main along the East Valley Highway was accomplished. 1959 Two pumping stations, two storage reservoirs and trans- mission mains were completed to serve the West Hill area of Kent. 1964 The Clark Springs Water Supply Main from Kent Springs to Kent was completed. This provides the City of Kent with a second independent transmission main for supply of water. 1965 The construction of North Industrial Water mains serving areas adjacent to the West Valley Highway, South 212th Street and South 228th Street was completed. 1966 Federal funds from the Department of Economic Development Administration were obtained to pay a portion of the costs of additional water mains to serve the North Kent area, two (2) six million gallon water storage reservoirs to- gether with required transmission facilities, construction of wells and pumping stations to increase the capacity of Clark Springs and a roof over the existing three million gallon ground reservoir on Guiberson Street. 1967 Construction was started on the 6 MG Reservoir at 240th and 98th Avenue South. 1968 Construction of the six million gallon reservoir at 240th and 98th Avenue South was completed. 19 I *1969 The S. 218th St. Supply Main was completed from the 6 MG reservoir at S. 240th St. and 98th Avenue South to the North Industrial Area. The construction of Phase 2 of the North Industrial Water Mains and the S. 180th St. mains were completed. The expansion of the Clark Springs water supply was completed by the installation of a three well pumping system. The roof over the 3 MG reservoir was completed. *1970 The 6 MG concrete reservoir on S. 218th Street and ad- jacent supply lines were planned and placed under con- struction. *1971 Construction was completed on the S. 218th St. reser- voir and adjacent supply lines. �N q• i g• *Progress since Phase I Study completed. 20 CHAPTER IV POPULATION In establishing the water source requirement for the projected study area, it is necessary to establish reasonable estimates of the probable rate of demand at various intervals during the study period . A necessary factor in any estimate of future consumption is that of future population. Although the basic unit used for presenting and estimating pop- ulation is the study area, this basic area has been divided into neighborhoods. These neighborhoods have been further divided into eastern area neighborhoods and western area neighborhoods which when combined, comprises the entire area within the study area boundaries shown on Figure 4-2. Various factors affecting the growth of each of these areas have been evaluated prior to final selection of a figure for the population estimate. The extent of population predictions vary generally from ten to forty years. A forecast period of 32 years was selected for this report to project population figures to the year 2000. FACTORS AFFECTING GROWTH There are three basic assumptions that must be made in fore- casting the development of an area as a whole : First, that the present employment centers will continue to flourish in the same locations and will be the major influencing factor, in the locations of residential areas. Second, that the contemplated freeways , bridges and other major arterial highways , which must be taken into consideration in the distribution of population during the projection period will, in fact, be completed.. Third, that the density patterns in the projected period will be about the same as at the present time. or, that these densities will change only in accordance with comprehensive plans that are currently in existence. The following factors were considered as they affect the pre- diction of population within the boundaries chosen for the study area of this report. 1. Land use, population concentration and type of zoning both existing and proposed for the areas under consider- ation. 2. Industrial and economic changes. 23 3. Political and geographic limitations of the areas. 4. Saturation levels based on the concept that population tends to reach a limiting value for a given area. SOURCES OF POPULATION DATA Population data was gathered utilizing the information con- tained in the following reports . j 1. Population Projection by Planning Area, Distribution by Neighborhood, 1960-1970-1985 -- Saturation prepared by the King County Planning Department. 2. Green River Valley Transportation Plan completed in July 1967. 3. A Guide for. School Planning. A report dealing primarily with school enrollment projection. for King County. 4 . The Kent Comprehensive Plan, 1967-1987 . POPULATION PROJECTION - STUDY AREA It is important to make a distinction between the termsro- jection and distribution. Projection is a mechanical process whereby future' popu=ation is estimated based on certain assumptions . Distribution, on the other hand, refers to the allocation of the projected population to prescribed _geographical areas. The total of the distributed population (neighborhoods) must always equal the ¢ projected population for the study area. The King County Planning Department, in their report, Population Projection by Planning Area, provided the basis for setting up dis- tribution neighborhoods throughout the study area. However, the information contained in this report did not cover the entire study area. Therefore, a careful analvsis was made of the Green River Valley Transportation Plan wherein population was projected to the year 1985. A Guide for School Planning was also reviewed and compared to later population reports. The Kent Comprehensive Plan was carefully analyzed and some adjustments were made to the year two thousand. The area designated in Figure 4-2 and Table 4-1 , as eastern area neighborhoods required special consideration since this area fell outside of the boundaries covered by the King County Planning Depart- ments report. This area is presently extremely sparcely populated with a density of approximately one family per 13 acres. It is well out of the King County urbanizing area and located in the foot- 24 hills of the Cascades. School enrollment data in these areas shows growth within the Black Diamond School District remaining nearly static over the years and because of the distance to employment centers and poor highway access in this area, it would normally be expected that this area would continue to grow at a rate consider- ably slower than the more accessible regions of the county. There are several exceptions to this growth pattern, however. The first exception being the amenity areas around the lakes , to which have been applied a selected rate of increase approximately that of the county as a whole. The other exceptions are those areas in which large plats are currently being developed or are planned. One ex- ample of such an area is the Covington Plat which is being developed under the FHA CHOICE Program. Because of the rough topography of the rest of this eastern area, a saturation would occur sometime after the year 2000. Table 4-1 presents population projections to 1970 , 1985 , and 2000 for the study area, with those projections distributed by neighborhoods , which are indicated on Figure 4-2. In Figure 4-1 , the population trends of the study area are plotted as a whole . SERVICE AREA POPULATION The present service area, which is comprised of the City of Kent and King County Water District 87, 105 and 111, served a population of 24 , 000 people in 1967. If the City of Kent does not extend its service area, this service area will continued to grow at the same rate as the entire study area. This pattern will probably be accelerated, however_ , by annexation and extension of service to Water Districts ' and other areas in the County. In projecting the growth of the service area, we have projected the service area at an accelerated rate of growth so that the popu- lation of the service area would equal that of the study area at 2000. In doing so, we are assuming that the entire study area will. be served with either Kent water, Seattle water, or a combination of both, at the, year 2000. In Figure 4-1 are plotted the population trends of the service area, in relation to the study area. 25 Table 4- 1 STUDY AREA POPU LATION ESTIMATE Mstribution by neighborhood western Area Neighborhood 1960 1970 1985 2000 1 9104 17700 21000 33000 2 850 1500 3200 6300* 3 550 1600 4200 6700* 4 860 1600 2100 3900* 5 440 950 2800 5700*- 6 110 700 2100 3800* 7 150 700 2100 3900* 8 120 700 2400 4600* 9 1680 3000 3100 4800* 10 370 700 2400 4400* 11 450 1000 2100 4400* 12 330 700 2400 5000* 13 810 1600 2400 4300* 14 200 700 2100 4200* 15 90 700 1700 3400* 16 190 I 1000 2400 430,0* 17 110 350 1400 3500* 18 130 700 2100 4000* 19 320 700 2100 4300* 20 280 700 1700 3700* 21 1000 6000 12000 19000 22 850 1200 4000 11000 Sub-total 18990 44500 81800 148200 Eastern Area Nei hborhood 1960 1970 1985 2000 E-1 500 80.0 3000 5500 E-2 640 1000 2300 3400 E-3 390 900 2000 2600 E-4 100 150 400 900 E-5 320 500 1200 2100 E-6 150 200 500 1000 E-7 420 800 1600 2400 Sub-total 2520 4350 11000 17900 TOTAL 21510 48850 92800 166100 b * Saturation figures occurring before 2000 26 Figure 4-1 POPULATION TRENDS 1,000 500 at — p 200 0 .,C 100 Stud Studw Are _ •�• VO r•+ ••• SO00, • p'" •'••® Service A r a 20 • s• l0 1960 1970 1980 1990 2000 Ye a r 6 I I CHAPTER V WATER USAGE ` CHAPTER V WATER USAGE M As previouslystated,, the purpose of this study is to develop a Comprehensive Plan of water source development to assure the City of Rent and adjacent areas adequate supplies of high quality water. In accomplishing this purpose, the study includes among its objec- tives the evaluation of both developed and potential sources of sup- P ly, together with estimates of projected and future water require- ments. WATER CONSUMPTION A knowledge of the quantities of water required is essential to the evaluation of water sources and the planning of their Bevel- ; l opment. Since such evaluation and planning is concerned with water use at some future date, the quantities of water required must of necessity, be approximated. However, through analysis of the var- ious factors which influence water consumption, reasonable estimates of the requirements can be developed. In estimating future water requirements consumption is usually expressed in gallons per capita per day (GPCD) . This value repre- sents the annual average consumption based on the entire population and includes all uses . The general classifications customarily are either domestic, commercial, industrial or public consumption. r- DOMESTIC CONSUMPTION The physiological needs of man require less than a gallon of water daily. Yet his demand for water for other purposes is such that average domestic consumption values between 60 and 100 GPCD are common. Values in excess of 100 GPCD are not at all unusual. Historically, the amount of water consumed domestically has been increasing and it is anticipated that this trend will continue. Most of the water delivered to homes is used in the kitchen, laun- dry and bath with lesser amounts used out of doors for lawn and garden irrigation. COMMERCIAL AND INDUSTRIAL CONSUMPTION As may be determined, from the following examples of estimates of commercial water use, consumption in such commercial establish- ments as restaurants is somewhat higher than others. k 30 I I TABLE 5-1 COMMERCIAL WATER CONSUMPTION Beauty Shop 125 GPCD per chair Dentists Office 750 GPCD per chair Department Store 40 GPCD per employee Drug Store 500 GPCD Hotel 125 GPCD per room Office Building 25 GPCD per employee Physicians Office 200 GPCD per examining room Restaurant 20-120 GPCD per seat The major water usages in industry are for cooling and proces- sing. The amounts of water consumed in a given plant are a function not only of product but also of methods, processes and operations in- volved. Thus, consumption can and does vary between plants dealing in the same products. TABLE 5-2. INDUSTRIAL WATER CONSUMPTIONv Steel 65,000 gallons per ton Bleached Pulp 70,000 gallons per ton f- Paper 30,000 gallons per ton Beet Sugar 3,000 gallons per ton Processed Oil 770 gallons per barrel Aluminum 30, 000 gallons .per ton Meat Packing 2,200 gallons per animal Processed Milk 5 gallons per gallon FIRE DEMAND Although the total amount of water used for extinguishing fires usually is a negligible portion of annual consumption the rate at which it must be supplied is so great that in all but the largest communities, fire flows are the largest demands imposed on water systems. Since fire protection is of primary importance, the plan- ning and design of water works must include consideration of such demands. 31 TABLE 5-3. NATIONAL BOARD OF FIRE UNDERWRITERS REQUIRED FIRE FLOW Required Fire Flow Duration Population for Average City Hours IMM mom. 1000 1,000 1.44 4 1500 10250 1. 80 5 2000 1,500 2 .16 6 3000 1, 750 2.52 7 4000 2,000 2 . 88 8 5000 2 ,250 3.24 9 6000 2, 500 3.60 10 10000 3,000 4 . 32 10 13000 3,500 5.04 10 17000 4 ,000 5.76 10 22000 4 , 500 6 .48 10 27000 50000 7.20 10 33000 5, 500 7.92 10 40000 6,000 8.64 10 55000 7 , 000 10.08 10 75000 8, 000 11.52 10 95000 9, 000 12 .96 10 120000 10, 000 14.40 10 150000 11,000 15. 84 10 200000 12 , 000 17.28 10 Over 200, 000 population, 12 ,000 gpm, with 2,000 to 8,000 gpm additional for a second fire, for a 10 hour duration. The fire flow to be provided is determined by such factors as the size, type and concentration of buildings, which in turn are a function of community size. Required fire flows for average cities have been established by the National Board of Fire Underwriters as one of the general standards used in classification of communities for insurance purposes . These required flows presented in Table 5-3 were obtained from the grading schedule published by the NBFU. The schedule also provides for fire flows of 500 gpm under certain conditions in residential districts. However, in recent discus- sions with local representatives of the National Board, they indi- cated that this minimum is expected to be increased to 1,000 gpm in the near future. DESIGN QUANTITIES When available, actual consumption figures provide the most reliable basis for water works planning. When such figures are unavailable, the records of other areas can be used provided that allowance is made for any characteristics which might significantly effect water consumption. In the planning of facilities for rela- 32 tively undeveloped areas, consideration should be given to the potential for urban development resulting in not only a greater number of consumers but higher per capita consumption as well. In Figure 5 -1, the annual average water usage for the City of Kent and its variations for each month during 1967 , is plotted. Figure 5-2, a reprint of a graph which appeared in a 1955 re- port, shows the annual average water consumption and its variations for each month for 1954 . The shape of both graphs are the same, with the peak consump- tion occurring in August, however, the numbers have changed in the past 13 years. The month of August in 1954 had an average daily consumption of 1.85 MGD, while the same month in 1967 had an aver- age daily consumption of 6 .5 MGD. These graphs point out very dramatically, that any source of supply must be capable of supplying more than the average amount of water required each day. A water source, in addition to supplying water for the average day, must be able to meet the requirements of the peak month, peak week and, if no storage is available, even the peak day. For the long-range design of water supply facilities, the following factors must be taken into consideration. Period Percent of Average Peak 30 Days 150% Peak Week 175% Peak Day 200% This tells us that on the hottest day in August, the city will require twice as much water as on an "average day" . In 1954 , per capita consumption for the City of Kent was repor- ted at 113-125 GPCD during maximum demand periods. These figures did not include the canneries, which if included, would raise those figures to approximately 470 GPCD. Per capita consumption for the City of Kent, was in the past, a small part of the total consumption. The canneries have always been the major consumer of water in the city; however, as an area grows in size and population, a more stable level of water usage is reached, which can be predicted in terms of per capita consumption. In 1967 the City of Kent served approximately 24 ,000 consumers and resulted in an average consumption of 183 GPCD. As the City and the study area grow, the effect of increased population will tend to reduce this quantity even further, while at the same time the tendancy of the consumer is to use more water. 33 q i For the 32 year design period ending in 2000, the planning of water supply facilities for the City of Kent is predicted on an av- erage daily consumption of 170 GPCD and a maximum daily consumption of 340 GPCD. These rates have been selected in anticipation that the following conditions will be substantially fulfilled: 1. Future development in the City of Kent will be primarily d industrial in the Valle - commercial an Y floor and primar ily residential in the surrounding areas. In much of the area, the quality of residential development will be above average. 2. Water services will for the most part be metered. 3. The more populated areas of the City will be served by sanitary sewer systems. In Figure 5-3, the average and peak daily consumption of the study area is plotted. This graph shows the amount of water re- quired for the study area at any time during the study period. In Figure 5-4 is plotted the average and peak daily consump- tion for the service. area, as it grows toward the size of the study area. This Figure is used in the planning of source development and tells at a glance, the projected amount of water required at any period in time. r ,I 34 Figure 5 .1 KENT AVERAGE ANNUAL WATER USAGE ( Metered water only) 1967 6 5 s 'fl An ual average m 4 - - - — 0 s eo a g - - - 0 2 r 1 — 0 F MIAIMIJI SJOINIDIJIF 1967 6::8:j d Figure 5-2 KENT AVERAGE ANNUAL WATER USAGE (Metered water only) 1954 6 5 a� 4 0 0 3 0 .r 2 Wool Annual ave a e I — — — M A M A S O N D g55 1954 Figure 5-3 STUDY AREA PROJECTED WATER USAGE 100 50 . • Plls ak d ily dei land • oo `' II to'00 2 O •. IAA erage daily dem nd gpcd) .° 10 as 0 5 1 1960 1970 1980 1990 2000 Yea r Figure 5.4 SERVICE AREA PROJECTED WATER USAGE 100 1 50 i a, ♦ aPeak daily 10 dema d 20 00, t • s ° 10 . 407, Avers ge da ly de mand (1706 d) r 2 1 1960 1970 1980 1990 2000 Year r CHAPTER VI i WATER RESOURCES CHAPTER `II WATER RESOURCES Water resources may be classified as meteorological, surface, or ground waters, each distinguished by certain characteristics . Meteorological waters are precipitated from the atmosphere as rain, snow, hail, etc. They are used as a public water supply, mainly on oceanic islands, where other sources are not available. Meteorological waters as a source, have not been considered in this report. Surface waters provide the most common source of large muni- cipal supplies and generally speaking, throughout the United States, surface waters are the most important source of supply for large cities. This is also generally true in the Pacific Northwest, as can be evidenced by the City of Seattle and the City of Tacoma, who are the north and south neighbors of the City of Kent. Surface waters as a source, have been considered in this report only in the form of Seattle Transmission Lines and their availability to the City of Kent. Further discussion of the Seattle Transmission j lines is included later in this chapter. Ground waters are natural waters which are found below the surface of the ground and in general are satisfactory for consump- tion without treatment. The City of Kent presently fulfills its water requirements with ground water and the bulk of this chapter presents an evaluation of the potential ground water sources of supply for the City of Kent. It is well, therefore, that we include some information on the geology and the occurence of ground water before we discuss these potential development areas. GEOLOGY The area of Western Washington in the vicinity of Kent is under® lain by consolidated Tertiary bedrock formations which are chiefly sandstone, siltstone and shale, with occasional coal beds. The bed- rock formations are exposed in places east of Kent, at higher eleva- tions, and also in the valleys or gorges of some of the major streams . Throughout most of the area, however, the Tertiary bedrock is cover- ed by glacial deposits to depths of as much as 1000 feet. The glacial deposits are the result of the erosion and deposi- tion activity of the Continental Ice Sheet which advanced into this ti area during the Ice Age (Pleistocene period of geologic time) . The 40 Puget lobe of the Cordilleran Ice Sheet of British Columbia advanced southward four different times into this part of Western Washington. The designation of these glacial and inter-glacial periods is as follows : Post glacial (recent) Fraser glaciation (Vashon Stage (Puget Lobe) (Evans Creek Stage (Alpine) Olympia interglaciation Salmon Springs glaciation Puyallup interglaciation Stuck glaciation Alderton interglaciation Orting glaciation The four alternating advances and retreats of the Ice Sheet into the area brought in large quantities of glacial debris which was deposited upon the underlying land surface, together with de- positing large quantities of alluvial materials in the meltwater channels issuing from the margins of the glacier. The general designation for all of these deposits resulting from the activity of the ice sheet is glacial drift. Glacial till is a type of drift which is primarily clay with sand, gravel or boulders mixed into the clay matrix. Ice contact deposits are a type of drift which has been deposited at the margin of the ice sheet by running water or in standing water and are generally composed primarily of sands and gravels and are usually stratified. Outwash deposits are usually sand and gravel deposits which have been laid down in the channel of water issuing from the margin of the Ice Sheet at some distance from the edge of the glacier. These outwash deposits are sometimes designated as advance outwash or recessional outwash de- pending upon whether they were deposited during periods when the Ice Sheet was advancing into, or retreating from, the particular area. The principal valleys in the area under consideration are those of the Cedar River (near Renton) , the Green River, the White River, and the Duwamish Valley which is the designation given to the broad north-south trending valley between Auburn and Kent. The principal physiographic areas between or adjacent to these valleys are as follows : The Des Moines drift plain lying west of the Duwamish Valley; the Coalfield drift plain lying north of the Cedar River; the Covington drift plain between the Cedar and Green Rivers; and the Osceola mud flow lying south of the Green River. k 41 w, After the end of the Vashon Stage of the Fraser glaciation, which occurred some 13 , 500 to 15, 000 years ago, the Duwamish embay- r ment west of Kent was filled in with alluvial deposits, the pre- sent valleys of the Cedar, Green and White Rivers were cut down by stream erosion and the Osceola mud flow was deposited from the slope of Mt. Rainier in the area south of the Green River. During this interval of time the Green and White Rivers deposited allu- vial fans along the eastern edge of the Duwamish Valley where these rivers issued into still water or onto gently sloping land from the higher areas to the east. Although the present topography is the result of recent ero- sion or deposition, much of it reflects older topographic features which were created during the glacial period. An example would be the broad channel which trends southwesterly from near Maple Valley to beyond Covington. This probably represents an abandoned melt- water channel. OCCURRENCE OF GROUNDWATER Although small quantities of groundwater can be produced from wells into almost any of the alluvial, glacial, or bedrock deposits, the aquifers of principal importance from a standpoint of potential municipal water supply are the permeable sands and gravels of either alluvial or glacial origin. Principal Aquifers E. The most productive aquifers in the vicinity of Kent are found in the Salmon Springs drift, the advance or recessional outwash and ice contact deposits of the Vashon drift, and the alluvial fans near Auburn and to the north near Renton. Records from existing wells in the permeable deposits of the Salmon Springs or Vashon drifts show specific capacities ranging from 10 to 100 gpm per foot of drawdown at depths less than 400 feet. Wells into the permeable sands and gravels of the alluvial fans near Auburn or Renton, are very productive with specific capacities rang- ing from 50 to more than 500 gpm per foot of drawdown at depths of less than 100 feet. The permeability of other formations in the area, such as the fine grain alluvial . sediments to the west of Kent or the clayey de- posits of glacial age, is too low to permit development of high capacity wells that would be suitable for municipal supply. d. 42 Recharge • Recharge to the groundwater aquifer occurs from rainfall on the area or, in some cases, from infiltration of water from streams into the underlying or adjacent formations. Rainfall at Kent is approximately 38 inches annually. The precipitation increases towards Auburn (45 inches) and to the east at Black Diamond (50 inches) and Maple Valley (53 inches) . The available recharge is in excess of groundwater withdraw- als and there appears to be ample replenishment to support a con- siderable expansion of the existing groundwater developments. Only at a few individual localities, such as the City of Kent' s develop- ment at Clark Springs, is the present development approximately equal to the available groundwater supply. Quality of Water The chemical quality of groundwater in the vicinity of Kent is generally suitable for municipal water supply. The hardness of the water available from the Salmon Springs drift deposits, from ice contact deposits and from the outwash deposits of Vashon age, is generally less than 100 parts per million. Temperature of the water is generally between 45 and 55 degrees F. The only problem with groundwater quality is the presence at some locations of undesirable quantities of dissolved iron or man- ganese in the water. Water with excessive iron or manganese may be associated with peat deposits encountered in drilling at some localities, as well as being found in other wells at scattered locations which penetrate either alluvial or glacial sands and gravels. Exploratory drilling and sampling of the water for chem- ical analysis should precede any large-scale water-supply develop- ment that is contemplated. POTENTIAL DEVELOPMENT AREAS Presented in this section of the chapter is an evaluation of j the potential groundwater resources of the City of Kent and the j potential for new development or additional development at sites. already being used to supply water to the City and those sites which have been considered or suggested to the City in the past. The location of the sites discussed is shown in Figure 6-1. Although not a groundwater source, this chapter includes a brief discussion of the Seattle Transmission lines as a source and the location of these lines is shown in Figure 6-1. 1 This section of the chapter is based on field examinations, 43 r p I information in our files and upon records (published and unpub- lished) in the files of the U. S. Geological Survey and State Department of Water Resources. II e. I Kent Springs Kent Springs are located in the South 1/2 of Section 33 , Town- ship 22 North, Range 6 East, W.M. The City of Kent owns the South- east 1/4 of the Southwest 1/4 and the Southwest 1/4 of the South- east 1/4 of Section 33. The springs discharge groundwater from sand and gravel depo- sits which are of Vashon recessional outwash origin. The area which is about 8 1/2 miles east of Kent, has been developed by the City of Kent for a source of municipal water. A concrete infiltra- tion pipe is buried at shallow depth in the glacial gravels and water is collected and transmitted by gravity through a main pipe- line to the city. The collection works are reported to have a capacity of 3. 0 million gallons per day (2400 gpm) , but the minimum flows observed in the past have been less than 3 mgd. One of the lowest observed flows from the infiltration system occurred in August 1952 when the discharge to the city was between 2 .4 and 3 .0 mgd - probably approximately 2 . 8 mgd or 2250 gpm. No drilling exploration has been done at this locality, but it is probable that the present development only "skims" off the upper portion of the aquifer and that additional groundwater is available at this site either from a deeper infiltration collection system, or from drilled wells, or from a combination of the two such as has taken place at Clark Springs. Although additional ex- ploration would be required , it seems likely according to the Groundwater Geologists evaluation that a firm supply of as much as 6.5 mgd might be available economically from this location. The Kent Springs area has the advantage that the city already controls the property, the water is known to be of good quality, and further development would probably not result in any interfer- ence with other groundwater used in the vicinity. Clark Springs The Clark Springs area is in the South 1/2 of Section 26 , Township 22 North, Range 7 East, W.M. , approximately 10 miles east of Kent. The City of Kent, in 1957-58 , installed an infiltration gallery pipe collection system which was later enlarged and expanded in 1963 to provide a gravity supply of from 3 1/2 to 4 million gallons per day. In 1967-68 , the infiltration system was further supplemented by the drilling of three wells which will have a total installed 44 Isolate Kent Valley and West Hill areas from Kent Water System. At this time, the Kent Valley, West hill and all low level areas below these reservoirs would be served with water purchased from the City of Seattle. The East Hill, Park Orchard and Water Districts No. Ill and No. 105 would be served from Kent' s exist- ing sources . 6 . Develop Kent Springs in same manner as 1978 Clark Springs, complete with pumping facil- ities . Construct approximately 39, 400 feet of 21" and 24" diameter transmission main from Kent Springs to the City. 7. The City of Seattle ' s 30" diameter trans- 1980-1985 mission main is available for service to Water District No. 111 and No. 105 . r 1990 8 , Develop Armstrong Springs, including connection to the transmission main to the City. It is assumed that during 1980-1985 , District No. 111 and Water District No. 105 would dis- continue water service from Kent and purchase their water directly from the City of Seattle. At this time the City of Kent would continue to serve the eastern areas adjacent to the City with their existing sources. These areas consist of the intermediate and high level pressure zones and would extend generally from the projected line of Alvord Avenue to 124th Avenue S . E. The City would, of course , also have the option of serving these areas with Seattle water at any time in the future. In addition to the above steps, additional construction will occur periodically to provide the necessary facilities for supply- ing water to all areas . This would be true of both plans, and the construction necessary will be described in Phase II of this report covering transmission, storage and distribution. Plan A is easily adapted to stage construction and makes the maximum use of existing mains and appurtenances . This plan also provides for full utilization of Kent's present sources of water together with a potential source of water located immediately adja- 55 ` cent to transmission facilities . It also provides for the replace- ment of the Kent Springs transmission line from the source to the City of Kent. The advantage of this plan is the ease with which it can be put into effect and the lower initial cost of construction. In this plan, the major transmission mains are constructed by the City of Seattle and the only construction costs incurred by Kent are those necessary for connection to Seattle transmission mains , re- placement of an existing Kent transmission main and expansion of an existing source, together with development of one new source. The expansion and development of these sources are required to serve the eastern areas of Kent immediately adjacent to the city boundar- ies and also to serve Water District No. 111 and Water District No. 105, until 1980 to 1985 at which time it is anticipated that the City of Seattle will serve these districts . The disadvantage of Plan A is the inability of Kent to control possible rate increases once they are dependent upon Seattle for water. PLAN B - DLVELOPIIL14T - Plan B which emphasizes the continued ` development and expansion of Kent' s own sources , requires the acqui- sition and development of new watershed, in addition to the expan- sion of existing facilities. This plan would be developed in the following series of construction stages, which are also indicated in Figure 7-2. Item Description Year Completed 1. Complete pumping facilities at Clark Springs 1969 r 2. Test well drilling program to be under- 1969 taken at Armstrong Springs, Kent Springs and Covington Area . 3. Watershed Property a. If test drilling exploration results 1969 are satisfactory, acquire Armstrong Springs and Covington Sites . Also obtain Ranney Well property. b. Acquire additional property at Kent As soon as Springs and Clark Springs. possible 4 . Develop Armstrong Springs , including 1970 pumping facilities and approximately 24 , 000 ft. of 28" diameter transmission main to City. 5 . Develop wells in Covington area including 1974 pumping facilities and approximately 4500 56 i ft. of 16" diameter transmission main from Covington to Armstrong Springs . b . Develop Kent Springs in same manner as 1978 Clark Springs, complete with pumping facilities. Construct 15, 500 ft. of 24" diameter transmission line from Kent Springs to Armstrong Springs . 7 . The City of Seattle' s 30" diameter trans- 1980-1985 mission main is available for service to Water District No. 111 and No. 105. 8. Complete Ranney Well at site on Green River 1987 complete with pumping facilities and con- struct approximately 40, 000 ft. of 24" diameter pipe from well site to Kent. The date for construction of the Ranney Well was determined by the time Water District No. 111 and No. 105 would begin pur- chase of water from the City of Seattle in 1981. If this were not the case, the Ranney Well would have to be developed by 1981 and would serve the study area until 1987, at which time purchase of Seattle water by these areas would be a necessity. The principal advantage of Plan B is the ability to control water rates within Kent' s service area. The disadvantage of Plan B is the high construction costs which must be incurred over a short period of time . The mainten- ance and operating costs are considerably larger under this plan, but these have been included in the cost estimates to determine cost per cubic foot. w Plan B lends itself readily to stage construction and utilizes a majority of existing facilities . COST COMPARISON OF ALTERNATE PLANS To implement either Plan A or B will require capital outlay . In Tables 7-1 and 7-2 are listed the capital costs of the major improvements outlined previously under Plan A and B development. Construction costs were estimated from prices obtained from various sources , including contractors, manufacturers, suppliers, and records of previous similar projects . Construction costs have been rising in a general upward trend over the years. The Engineering News Record Cost Index has long been the criteria for estimating costs in the future. The costs shown below are based on the Engineering News Record Cost Index for 1968 and have been adjusted to the proposed date of construc- tion in accordance with the rise in the cost index. 57 The costs shown in the taLles are correctly termed PROJECT COSTS . These costs include the cost of watershed acquisition, right-of-way, contingencies , taxes , engineering , financial and legal services and all costs incurred during construction. TABLE 7-1 PLi-uN A - PROJECT COSTS PROJECT COSTS Item Description 1968 Projected 1 . Complete pumping facilities at $ 308 , 000 -- Clark Springs. 2 . Test Well Drilling at Armstrong $19 ,000 $21,000 Springs and Kent Springs . 3 . Watershed Property q- Fair Market a. Acquisition of Armstrong Springs Value Fair Marketb. Adcitional property at Kent Springs Value and Clark Springs 4 . 16" Diameter Transmission Main and $210 ,000 $240 ,000 pressure reducing station. 5 . Connection of City of Kent ' s Reser- $132 ,000 $162 ,UUU voirs to Seattle ' s 42" transmission main. 6, Develop Kent Springs, patterned $2 ,069 ,000 $2 , 850 ,000 after Clark Springs, including transmission. 7 . City of Seattle ' s transmission ;Hain Not a City of available to Water District No. 111 Kent expense and Water District No. 105 . Develop Armstrong Springs including $396 ,000 $690 ,U00 pumping and transmission. TABLE 7 -2 PLAN B - PROJECT COSTS PROJECT COSTS Item Description 1968 Projected 1 . Complete Pumping Facilities at $306 ,000 -- Clark Springs . 58 Figure 7- 2 PLAN B SERVICE AREA Supply vs. Demand W 100 50 Total eak daily eman I 8 ,a Pea sup lv 6 ,. 20 5 a c 4 10,00 1 7 10 a reak dai 1F dem n -- c 5 - 1 1960 1970 1980 1990 2000 Year Note: 1. Numbered ordinates to correspond to numbered items listed under Plan B development. 2 Dashed line indicates alternate based on availability of Seattle water to Rater District 105 and Water District Ill CHAPTER VIII FEDERAL - STATE -- FINANCIAL ASSISTANCE PROGRAMS As an assistance to local agencies , the Federal and State governments have established financial agencies for the purpose o4f :;.along grants and loans , especially to encourage the efficient and orderly growth and development of communities . In this chapter is presented a brief description of the pro- grams of Federal and State agencies which are currently making grants and loans and their regulatory requirements . ','he City of Rent has received aid for their water improve- r.:er.t program from the Economic Development Administration (EDA) in the form of a grant. Grants from the agencies listed below for continued water improvement programs is a very distinct pos- sibility, however , the amount of such grants can never be predicted , and for this reason all cost estimates for water improvements 's. were made without regard to government grants . BUREAU OF OUTDOOR RECREATION , DEPARTP,IENT OF INTERIOR The Bureau of Outdoor Recreation has a 50% grant for the acquisition of land - open space - park areas - watersheds and for the development of these types of facilities . The application for a grant must be submitted through the ;vashington State Inter-Agency Committee for Outdoor recreation in Olvmpia, Washington , which has a 25% grant matching program. The Bureau of Outdoor Recreation will not approve the grant request unless the State Inter-Agency Committee approves the project and allocates matching funds . ` The Bureau gives a higher priority for. the "acquisition" of land projects relating to open space than for a "development" project. WASHINGTON STATE INTER-AGENCY COMMITTEE FOR OUTDOOR RECREATION The Washington State Inter-Agency Committee for Outdoor Tecreation, State of Washington, has a 25% grant for the acquisi- tion of land, open space , park areas, watersheds and for the devel- opment of these types of facilities . Under certain conditions , tile State grant can be increased to 75% which can be used in lieu of the Bureau of Outdoor Recreation grant . The State gives a higher priority for the "acquisition" of lane; projects relating to open space than for a "development" project. The State also gives a higher priority to a broad base , non-revenue producing project and a lower priority for a limited public use project. 69 �IFP ART`IE NT OF HOUSING & URBAN DEVELOPMENT !nder Section 702 of the Housing and Urban Development Act of 1965 (public Law 89-117) , the Department of Housing and Urban f Development (HUD) is authorized to make grants to assist local pu:­�lic bodies and agencies in financing specific projects for basic water and sewer facilities . Direct grants are available to local public bodies and agencies to finance not to exceed 50 percent of the cost of con- structing new water and sewer projects , or enlarging or improving ( ir.cludirc rehabilitating) existing facilities . Grants are available to help finance specific projects for both water and sewer facilities . Water facilities include works to store , suppiv , treat, purify , or distribute water of sufficient quality and quantity for domestic, commercial and industrial use. A grant may be made for a water facilities project if it is determined that the proposed project is necessary to provide adequate water facilities and will contribute to the improvement of the health or living standards of the people to be served. In addition , the project must be: I le ( 1) Designed thtreasonablat an yguate ty will be growth needsaofabthe to serve he Y foreseeable area; (2) Consistent with a program for a unified or officially coordinated area-wide water facilities system as part of the comprehensively planned development of the area; and ( 3) Necessary to orderly community development. ` In order to qualify for a Housing and Urban Development grant, the City must have an approved comprehensive plan . In addition, each individual project must be approved by the Puget Sound Governmental Conference . The City of Seattle has prepared a comprehensive water source plan. This plan stresses the service of Seattle water to Water Districts and municipalities within their service area. The City of Event lies within their service area. In order to obtain ap- proval from the Puget Sound Governmental Conference for a Ilousir_g and Urban Development grant, it would appear that conformance to the City of Seattle ' s comprehensive plan would be a necessity. In addition, the Department of Housing and Urban Development has a 50% grant and a loan program, for the eligible portion of a project , for the acquisition of land - open space - park areas - and watershed projects . To a limited extent , the Department of Dousing and Urban Development has a SO'. grant for the "development" of these type facilities on land acquired through their program. 70 CHAPTER VII - A • SUPPLEMENTARY SOURCE PLANS CHAPTER VII - A SUPPLEMENTARY SOURCE PLANS The purpose of this chapter is to review the progress and items of work that have been completed since the Phase I , 1968 Water Source Study was published. In reading Chapter VII (previous chapter) we ask the reader' s consideration that this planning was done two years ago. The planning and concepts, however, are still pertinent and basically correct and for that reason it is important that these concepts be kept in mind as recent events are presented. After review and acceptance of the 1968 Water Source Study, the City proceeded with a groundwater investigation to explore the areas known as Kent Springs, Armstrong Springs and Covington. The detailed results of these explorations are contained in two reports prepared in 1969 by Anderson and Kelly, Consulting Geologist. These inves- tigations reveal that potentially goundwater is available from the prev'_ously mentioned areas , as follows : Kent Springs 10 . 0 MGD Armstrong Springs 2. 0 MGD Covington Area Not recommended for development Based on the findings of these groundwater investigations , the City in 1969 , acquired the Armstrong Springs area for a future water source. This area consists of approximately fifty acres of land covered with trees and vegetation, and crossed by Jenkins and Mar- tinez Creeks. The location of this area is approximately 660 feet south of the Kent-Kangley Road and just east of S. E. Wax Road. The Phase I Study was also concerned with the cost of Seattle water. At the time of the Phase I Report, the City of Seattle was updating their rate structure. An analysis and report were com- pleted in 1970 with the recommendation that a 14 . 5C per 100 cubic feet rate be established to water purveyors. Upon subsequent study and review, this rate was modified to 13. 5� per 100 cubic feet. Ordinance No. 99109 of the City of Seattle was then passed, making effective as of October 1, 1970 , the rate to be charged municipal- ities authorized to and engaging in the distribution of water of 13. 5� per 100 cubic feet for all water furnished. This ordinance also contains the provision that as of January 1, 1971, a schedule of monthly meter charges with respect to such municipalities be im- posed. The entire ordinance is contained in the Appendix of this report. On the basis of the information developed from the groundwater investigations and the new rate structure of the City of Seattle , the following determinations were made: 66 i i 1. Groundwater sources at Kent Springs were resolved to be 10. 0 MGD and 2 . 0 MGD at Armstrong Springs. The develop- ment of groundwater supplies was not recommended in the Covington area because of the relatively small amounts that might be realized from this area. The total amount of water estimated as available from these three areas in the Phase I Study , was a total of 13 MGD. In the de- tailed evaluation of groundwater availability, it is es- timated that the Kent Springs and Armstrong Springs areas can produce 12 MGD with the possibility of increasing the flow from these areas, 1 or 2 MGD. Thus , the development of these sources corresponds very closely to Plan A which is a utilization of the new Kent sources in the future and Seattle water immediately, as needed. The develop- ment of these two sources would, of course, also fit into Plan B, which is the use of the new Kent sources immediat- ely, and Seattle water in the future. 2. The unit cost of Seattle water based on their new rate schedule was established at 13. 5� per 100 cubic feet. This rate structure is still within the unit costs of water from Kent sources which varies from 13.0 to 15.2C per 100 cubic feet. 3 . Plan A, the utilization of Seattle water immediately, as needed, has a continued added advantage of not requiring any major capital expenses until 1978 as compared to Plan B, which emphasizes immediate expansion of Kent' s own sources with large expenditures in the very near future. 4 . Based upon these considerations , the planning and devel- opment of a comprehensive system of improvements antici- pating connection with the City of Seattle in the near future as needed, was continued. The planning of facil- ities for water transmission, storage and distribution, will be found in Chapter XIII , together with cost esti- mates of the improvements. 67 I f c Ii CHAPTER VIII FEDERAL - STATE - FINANCIAL ASSISTANCE PROGRAMS ECONOMIC DEVELOPMENT ADMINISTRATION - DEPARTMENT OF INTERIOR The Economic Development Administration has , basically, a 50% grant program. In order to be eligible for grants under this program, the project under consideration must be included in the King County Overall Economic Development Program. P-mong the factors considered in project eligibility are: a. Creation of permanent employment b. Unemployment rate of 6% or more (Commerce Department rate) . c. Maintaining of existing employment levels. I I I I i � i I i I i t I i I i 71 Chapter IX Design Criteria Chapter X Existing Water System Chapter XI Topographic Studies Chapter XII Computer Analysis of Existing System Chapter XIII Comprehensive Plan and Cost Estimate CHAPTER IX DESIGN CRITERIA CHAPTER IX DESIGN CRITERIA GENERAL In the development of Phase I of the Comprehensive Water Study, certain basic water usage criteria were established. Also, a study was made of past population trends. Based on these studies , an es- timated rate of growth was established. This predicted growth rate was used to estimate population densities within the study area for future years. The water usage rates were developed by dividing the quantity of water used by the number of customers served. In this manner, it was estimated than an average daily consumption of 170 gallons per capita per day (GPCD) and a maximum daily consumption of 340 gallons per capita per day (GPCD) would be realistic for the de- sign period. These consumption rates , together with the popula- tion figures established, were used to determine the quantity of water required to supply the service area at various times within the design period. In order to analyze the existing water distri- bution system, however, it was necessary to develop criteria by which it would be possible to approximate the actual distribution of the flows within the system. At the present time, the distribution of population within the service area varies quite widely, with some areas relatively undeveloped and others at maximum density. By the use of aerial photographs and by visual inspection, a determination was made of the present population distribution. In order to make a meaningful analysis of the existing dis- tribution and storage facilities , it also was necessary to approx- imate as closely as possible, a breakdown of the water usage among the customers served. This involved the determination of the proportionate amount of the total consumption required for resi- dential, commercial and industrial purposes, since the figure of 340 gallons per day (GPD) previously mentioned includes usage for all customers combined for the purpose of determining the total amount of water required for an adequate supply. RESIDENTIAL In the more densely settled residential areas of the City, an actual house count was made from aerial photographs. Using an average of 3. 5 people per residence, the density was estab- lished at approximately 15 persons per acre (PPA) which repre- 73 sents maximum density for areas of single family dwellings. Also, • the density ranging from 45-90 persons per acre (PPA) was used for areas containing apartments. The figure of 15 persons per acre 'PPA) was adjusted downward in areas where maximum density had not been reached. Water use criteria indicates a range of from 1 GPM to 1.25 GPM per service should be allowed for residential areas . These figures are for peak flow periods which, in most cities, occur during the evening hours when commercial and industrial usages have diminished. In the analysis of the areas of the City where indus- trial and commercial usage represented the largest demand, the peak flow period would not correspond with the peak residential demand. In these areas , a flow of 0. 8 GPM per residential service was assumed. In areas which are primarily residential , a flow of 3 . 5 GPM/acre was used for areas at maximum density. INDUSTRIAL In determining industrial flows , two methods were employed. Where some of the larger industrial users were known, metered con- sumption during the month of August, 1969 , were secured from the City records. These flows were then reduced to a gallon per minute 1 consumption rate. Some of the larger users include the Boeing Space Center, Western Farmer' s Association, the Coca Cola Bottling Plant, Stokely-Van Camp, Heath-Techna, and a number of trailer parks. The two largest users of this group, Western Farmer' s Association and Boeing Space Center, have a usage rate of 710 GPM and 516 GPM, respectively, with the remaining firms having usage rates ranging from 185 GPM to 40 GPM. In the analysis of the existing system, these usage rates were used as actually derived from metered consumption. In other industrial areas , where the usage rate was not known, demands common to similar industrial areas were used. A review of information pertaining to industrial usage, indicated that a flow rate of 2 GPM per acre for industrial areas would be realis- tic. In analyzing the usage rate of the Boeing Space Center , this usage rate is further substantiated. This installation occupies approximately 250 acres , with a usage rate of approximately 500 GPM, or an average rate of 2 GPM per acre. COMMERCIAL In commercial areas the quantity of water that is consumed in GPCD, ranges from 10 to 130. Common population densities for mercantile and commercial areas , ranges from 15 to 30 persons. 74 Selecting from these figures, an average population density of 22 - 23 PPA, and a usage rate of from 70 - 80 GPCD, results in an average usage rate of approximately 2. 5 GPM per acre for mercantile and com- mercial areas. SCHOOLS A study of the graph shown in Phase I of this report, which shows the total quantity of water used for various months, indicates that the maximum usage rate occurs during the month of August and the early part of September. Since this period corresponds with the beg- inning of the school year, an allowance was made ed the schools. A record of water used by schools ino the astudy ter sareaywas obtained from the Kent School District. A study of these records shows that an average of 4. 35 gallons per pupil er the elementary schools and an average of six all d onsper ay was used in day was used in the junior and senior high schools. Inorl dertoer translate this information into a flow rate and GPM required for the schools, it was necessary to make some assumptions. It was assumed that the bulk of this water would be used during a period o corresponding r f time p nding with the recess periods and the noon hour. Based on this usage period, and using a number of students enrolled at the schools, it was determined that the average of 0. 08 gallons per min- ute per student was used at the elementary schools and an average of 0. 145 gallons per minute per student was used at the junior and senior high schools. APARTMENTS ` The usage rate in apartment areas varies quite widely, depend- ing on the size of the apartments and the density. Based on these variables, and the per capita consumption common for apartment com- plexes, the usage rate in apartment areas can vary from 4 to 12 GPM per acre. FLOW RATE SUMMARY The various flow rates utilized in the computer analysis of the Kent Water System are set forth in the following tabulation. LAND USE FLOW RATE IN GPM/ACRE Residential 3. 5 (a) Industrial 2. 0 Mercantile & Commercial 2. 5 Apartments 4 . 0 to 12. 0 (b) (a) Adjustment made for areas at less than maximum density. (b) Dependent on type of apartment complex. 75 i SCHOOLS GPM/STUDENT Elementary 0 .08 Jr. & Sr. High 0 . 145 E FIRE DEMAND Although the total amount of water used for fire fighting purposes is a negligible portion of annual consumption, the rate at which it must be supplied is so great, that in all but the largest of communities , fire flows are the largest demands im- posed on water systems. The capacity of distribution systems is dictated by domestic, industrial, and other normal water uses and by the standby, or ready to serve, requirements for fire fighting. If there were no fire hazards, the hydraulic capacity of the distribution system would be designed to meet the maximum demand for domestic, industrial, commercial, and other general uses. For absolute safety, the fire demand would then be added to this figure. Ordinarily this is not done; (1) because it would be most unusual for the ;Maximum usage to coincide with a serious fire; and (2) because systems are designed to allow for future expansion, and improvements required for anticipated increased usage are generally undertaken and completed before the designed capacity of the original system has been reached. A fire flow requirement of 1, 000 GPM for a residential area is considered adequate by the Washington Surveying and Rating Bureau, and has been used in the analysis of the Kent Water System. However, substantially higher flows are required for fire fighting purposes in industrial and commercial areas. Information obtained from the Rating Bureau gives a required fire flow for the main Mercantile area of the City of Kent, of 3500 GPM. For large industrial and commercial buildings and for schools , the Rating Bureau now employs a. method by which the required fire flow is obtained on an individual risk basis . Among the factors considered in this method are square foot area, height, type of construction and number of exposures . Required fire flows up to 5 , 000 GPM for individual buildings rated in this manner, are not uncommon. Fire flows exceeding 5 ,000 GPM are required for unusually large buildings of high risk. In many of these instances, on site provisions must be made to meet this required flow. The main distribution network within the industrial area of the Kent Valley was designed in anticipation of increased industrial demands for water. This system has considerably more capacity than that required to furnish the quantity of water needed to supply present industrial, commercial and other 76 General demands. However, in order to determine the amount of capa- city available for future increased demands , it is necessary to con- sider, in addition to present normal peak usage, an additional quan- tity required for fire demand. Information was obtained from the Rating Bureau regarding fire flows which they have established for various industrial buildings in the Kent Valley. The flows established for these buildings has not generally exceeded 5, 000 GPM. As. yet, no required fire flow has been established for the Boeing Space Center. As a result of the discussions and the information obtained from the Rating Bureau, it was determined that a fire flow of 5 , 000 GPM would be a realistic maximum which should be provided. In the analysis of the existing system, this quantity was used in conjunction with nor- mal peak usage in determining the capacity of the ayStem. Since a fire of the magnitude which would require a flow of fla ration of major proportions, GPM would represent a con 7 P 5, 000 p g it was assumed that the City of Kent would take whatever emergency measures practical to make this quantity of water available. When analyzing the system on the basis of these maximum flows, it was assumed that pumping to the West Hill system could be temporarily suspended. 1 During the spring of 1968, an engineering report on exterior fire protection for a number of schools was prepared for the Kent School District. At all of the schools under study, insufficient water was available for fire protection. A number of the schools for which the study was prepared are supplied with water from the East Hill and East Hill Intermediate Systems. These schools are Kent-Meridian High School, Sequoia Junior High, Park Orchard Ele- mentary. The fire flow requirements for these schools ranged from 2, 500 GPM for East Hill Elementary, to 5, 000 GPM for Kent-Meridian Senior High. Since it was previously determined that fire flows of this magnitude were not available for these schools , these maxi- mum demands were not considered in the analysis of the existing Bast Hill system. In analyzing the system on a future basis, in which certain recommended improvements to the system were assumed to have been constructed, these critical fire flows were incorpor- ated into the maximum demand anticipated. As can be seen by the flows required in the industrial area, the flows required at these schools are among the most critical demands which will be placed on the distribution system. Recommended improvements to the sys- tem have been routed to provide the required flows to these schools. FRICTION FACTOR In order to determine the head losses in the distribution system due to friction, it was necessary to select a "c" factor c to be used in the computations , This "c" factor is a constant 77 j accounting for surface roughness of the interior of the pipe. values of "c" commonly used for design purposes vary from 140 4n new cement lined cast iron or steel pipe, to 100 for cast iron pipe which has been in service for a number of years. Much Of the water pipe in the older section of town has been in ser- vice for many years and is largely unlined pipe. In the more recently developed sections of the City and in the industrial area of the valley, the distribution system is composed primarily of new cement lined cast iron pipe. In order to reflect both conditions, a "c" value of 120 , or an approximate average of the two conditions was selected. PIPELINES Transmission and distribution pipelines were planned for the ultimate development of proposed sources and for maximum anticipa- ted development of areas served. The capacity of pipelines pro- posed were selected to meet the present NBFU grading requirements. Pipelines which may be required in addition to those included t in the comprehensive plan as development continues should be design- ed to meet the criteria established for the comprehensive plan. Minimum pipeline sizes should be ten inches for all commercial and industrial areas and six inches for residential areas. All pipe- lines in commercial and industrial areas should form looped systems. Looped systems should be constructed in residential areas whenever possible and eight-inch minimum pipelines should be constructed for all unlooped systems with fire hydrants. Transmission pipelines as well as storage reservoirs were plan- ned on the basis of developing new sources and purchasing water from the City of Seattle as presented in Phase I of this study. If the sequence of developing new sources and purchasing water varies from that proposed in Phase I, the construction of facilities should be scheduled as required. RESERVOIRS Reservoirs were planned to provide sufficient quantities of water for domestic use with adequate reserves for emergency ser- vice to allow for interruption of supply and to provide a reserve for fire fighting. Storage capacities planned are generally based on providing one day' s storage at maximum rates (340 gpcd) for popu- lations anticipated through 1985. Although additional storage will be required beyond this period, the timing, size and location of these facilities can best be determined as the need for these faci- lities develops . 78 i g CHAPTER X EXISTING WATER SYSTEM t II CHAPTER X EXISTING WATER SYSTEM i GENERAL The City of Kent presently serves an area of approximately 15 square miles, together with three water districts, which receive their supply from the City of Kent. Water for this system is re- ceived from two sources; Clark Springs with a maximum capacity of approximately 7. 7 MGD and Kent Springs, with a maximum capacity of approximately 3 MGD. Water from these sources is transmitted to the City of Kent through the Clark Springs transmission main which terminates at the 6 MG Reservoir near the intersection of James Street and 98th Avenue South, and the Kent Springs trans- mission main which terminates at the Scenic Hill Reservoir. At the present time, the City has eight storage reservoirs with a combined capacity of approximately 18, 000, 00o gallons. This includes a new 6 MG reservoir constructed Street and now in service. on South 218th The distribution system consists of approximately 75 miles of water mains and is divided into five basic distribution sys- tems: the East Hill System, the East Hill Intermediate System, the Low Level or Valley System, the West Hill Intermediate System and the West Hill System. While these five basic systems serve the bulk of the City, several smaller areas are served from other pressure levels. More detailed descriptions of all of the individual service levels of the distribution system are outlined in the following paragraphs. Drawings of the distribution and storage system are shown in Figure 10-1 through 10-5. Since the area covered in this re- port is quite large, the map of the distribution system has been divided into five separate maps, with one map showing the East Hill System, three maps showing the Low Level and East Hill In- termediate Systems, and one map showing the two West Hill Sys- tems. A key map showing the relative position of these areas is included on each map. EAST HILL SYSTEM The East Hill System is served from a one million gallon standpipe located on 112th Avenue Southeast approximately 1200 s. 80 ~ feet north of Southeast 240th Street. This reservoir has a water surface elevation of 590 feet. The bulk of the distribution sys- tem served from this standpipe lies north of Southeast 240th from 100th Avenue Southeast to 124th Avenue Southeast and is composed of 12, 10, 8 and 6-inch diameter lines. From the intersection of Southeast 240th St. and 116h Avenue Southeast, a 12-inch line extends south along 116th Avenue south- east to the intersection with the Kent-Kangley Road. From this Point, an 8-inch line extends northwesterly along the Kent-Kangley Road to 104th Avenue Southeast. These two lines serve as the main distribution lines for the area south of South 240th Street. A number of 6-inch and 4-inch lines distribute the water locally. The City of Kent is presently in the process of constructing a 12-inch line from the intersection of 116th Avenue Southeast and the Kent-Kangley Road, south to the Derbyshire area. For the • purpose of analyzing the existing system, this line was considered to be installed. Water to the East Hill System is supplied from the Park Or- chard pump station, which in turn receives its supply from a 125, 000 gallon elevated storage tank located on James Street and 98th Avenue South. This elevated storage tank r-, One Million Gallon Standpipe Elevation 590 East Hill System j 3 £ afi" c } 81 is located at the terminus of the Clark Springs transmission main and receives its supply from this source. EAST HILL INTERMEDIATE SYSTEM In addition to supplying the Park Orchard Pump Station, the 125, 000 gallon elevated tank which has a water surface elevation of 485 feet, supplies an area surrounding the tank and also an area on Scenic Hill. The area surrounding the tank extends from South 228th Street to Kent-Kangley Road and from Alvord Avenue to 100th Avenue S. E. The area served on Scenic Hill extends generally from Maclyn Street to South 258th Street and is bounded on the West by Crest Avenue and Alexander Avenue. A 3-unit pump station on Reiten Road near Seattle Street supplies water through an 8-inch water main crossing the canyon and on 94th Avenue So. and James Street to the 125, 000 gallon elevated tank. This main is used for both supply and distribution purposes. An area between Van De Vanter Avenue and Titus Street is also served from the Intermediate System by means of pressure reducing valves. LOW LEVEL SYSTEM Also located at the intersection of James Street and 98th Ave. So. , is a 6 million gallon storage reservoir with a water surface elevation of 416 feet. This reservoir also receives its supply from the Clark Springs transmission main. At the present time, this reservoir is used as storage for the 240 foot water surface eleva- tion service area. Water from this 6 million gallon reservoir is transmitted to the 240-foot water surface level through a 16-inch r r:- 1+ w 125, 000 Gallon Elevated Tank - Elevation 485 and Six Million Gallon Reservoir - Elevation 416 82 transmission main running generally along 98th Avenue South, 94th Avenue South, South 222nd Street and 93rd Avenue South to the in- tersection of South 218th Street. At this ointfthe line is reduced by means of a pressure reducinghvalvesaure nd e transmitted through a 12-inch water main along South 218th Streetn to the 16-inch water main on East Valley Highway. The City of Kent has recently completed a 6 million gallon concrete reservoir on the south side of South 218th Street, imme- diately west of the southerly projection of 98th Avenue South. Also, the City completed a 12 and 16-inch main along South 218th Street from 93rd Avenue South to the new 6 million gallon reser- voir. This new reservoir will have a water service elevation of 240 feet, which will correspond with the water surface elevation of the 3 million gallon Scenic Hill reservoir. With the the South 218th Street reservoir and the two transmissionp mains nonf South 218th Street, water from the 16-inch main on 93rd Avenue will flow east through the 12-inch main on South 218th Street, to the new 6 million gallon reservoir. Water from the South 218th Street reservoir will then be transmitted through the 16-inch water main on South 218th Street, to the 16-inch water main on East Valley 4 Highway. The low level system serves the main portion of the mercan- tile and commercial areas of the City of Kent and entire valley floor. This system also serves King County Water District No. 87, located south of Green River. Also, water from this system is temPumpwillnbe described system inea subsequent vst This West Hill Sys- Portion of this chapter. The storage for the low level system consists of the 3 million gallon reservoir on Scenic Hill, the South 218th Street 6 million gallon reservoir recently completed and the 6 million gallon reser- voir at the intersection of 98th Avenue South and South 240th Street. Water for the South 240th Street reservoir and the South 218th Street reservoir are supplied from the Clark Springs transmission main. Under gravity conditions, this transmission main has a supply capa- bility of from 3 1/2 to 4 million gallons per day. Utilizing the Pumping facilities recently installed at Clark Springs, the trans- mission main has an ultimate capacity of a gallons per day. As previouslyapproximately 7. 7 million tity is used to supply the East HilltSystemout�andp Water nDistrict No. ill. The Scenic Hill reservoir is supplied through the Kent Springs transmission main. The collection works at Kent Springs are repor- ted to have a capacity of 3 million gallons per day, but flows sligh- tly less than this have been observed. two sources is not available to the CityTof Kent,he nhoweveed r,ttsincehese Water District No. 111 and Water District No. 105 receive their 83 SIX MILLION GALLON CONCRETE RESERVOIR-ELEVATIO14 240 { y t _v �Ff*...f' iiirisais '"" `y;• y,i�,e'. p. tL r i Reservoir Walls Under Construction l L t r [Inspection of Reservoir Access] 84 •L i I I I Scenic Hill Reservoir - Elevation 240 supply from these sources. The portion of the low level system serving the main mercan- tile and commercial areas of the City of Kent, and a sizeable re- sidential area, is a well gridded system which has been in ser- vice for many years. This system, for the most part, is composed of cast iron pipe ranging in size from 6 to 16-inch diameter. As the demand for water in the northern industrial area of the City of the City of Kent has increased over the years, the City has been involved in an almost constant program of improve- ments to provide the facilities to meet these increased demands. One of the most recent and largest of these improvement programs, known as the North Water System, was completed by the City in 1969. Under this improvement program, approximately nine miles of water mains consisting of 10, 12 and 16-inch diameter pipe, was instal- led. This project was designed to provide the basic distribution 4 network for the industrial area in the North Kent Valley. This distribution network was further expanded under LID 256 to the northern limits of the City of Kent on South 180th Street. The basic grid network of the low level system has ample re- serve capacity to provide adequate flows for a substantial amount of industrial and commercial growth. However, for increased re- liability some additional cross ties and line upsizing, will be required as the demand for water increases with the growth of the area. Recommendations as to the location, timing and extent of these improvements will be discussed in a subsequent section of this report. s, 85 6 WEST HILL INTERMEDIATE SYSTEM Water for the West Hill Systems is obtained from the 12-inch transmission main on the Kent-Des Moines Road. A pumping station located west of the Green River and immediately south of the Kent- Des Moines Road, pumps the water through a 12-inch main running along Lake Fenwick Road and Reith Road, to a one million gallon storage reservoir located along Reith Road at approximately So. 256th Street. This reservoir has a water surface elevation of 354 . 5 feet. This reservoir serves as intermediate storage for the West Hill System and a small distribution network lying east- erly of the reservoir location. WEST HILL SYSTEM From the one million gallon storage reservoir, the water is pumped through an 8-inch main on Reith Road, 42nd Avenue South, So. 262nd Street and 33rd Avenue South, to a 300,000 gallon stor- age reservoir located south of So. 264th Street between Military Road and Princeton Avenue. This reservoir has a water surface w elevation of 529 feet. The West Hill System, as presently developed, extends in gen- eral, from the Kent-Des Moines Highway on the north to So. 270th Street on the south, and from Interstate 5 on the west to approxi- mately 44th Avenue South on the east. This distribution system consists primarily of 8 and 6-inch diameter pipe with a small amount of 4-inch diameter pipe. In the past, the City has experienced pressure deficiencies in this area during times of heavy usage. This situation is at- tributable to a number of factors. The area served by this sys- tem extends approximately two miles from north to south and while serving a relatively large population, has no distribution lines larger than 8-inch diameter. Also, the storage reservoir serving the area is located in the extreme southerly portion of the system, and water required to supply the northern areas must be transported relatively long distances. While the pipe sizes and tank location contribute somewhat to the pressure deficiencies occasionally experienced, the major contributing factor involves the topography of the service area in relation to the water surface elevation of the storage tank. The preceding limiting factors will be fully discussed in subse- quent sections of this report and improvement recommended. 86 !w r 'taw + �f� i ��`',��? .•j � �, 01 Millionone •n Reservoir Elevation • West Hill • Station t , 300 ,000 Gallon Elevated Tank Elevation f i CHAPTER XI s� TOPOGRAPHIC STUDIES t CHAPTER XI TOPOGRAPHIC STUDIES GENERAL The topography of the study area, as it influences the water surface elevation of the storage required to serve the various service levels, can be divided generally into three distinct areas: the East Hill area, the West Hill area and the valley floor of the Green River, which separates these two areas. The alluvial plain of the Green River, which comprises approximately 50 percent of the study area, varies very little in elevation. Elevations range from approximately 20 feet above sea level on the northern end to approximately 50 feet above sea level on the south- ern end. From the valley floor, the elevations rise rather abrup- tly to the higher ground bordering the valley on the east and west sides. As a result of this abrupt transition, only a relatively small amount of the service area lies in the zone separating the valley floor from the adjacent uplands. Elevations within the study area range from a minimum of ap- proximately 20 feet above sea level in the northerly portion of the valley to a maximum of approximately 500 feet above sea level in the area served by the East Hill system. At the present time, the City of Kent has established service levels with the follow- ing water surface elevations : 590 feet serving the East Hill, 485 feet serving a small area in the transitional zone between the East Hill and the low level system, 240 feet serving the Low Level system, 354. 5 feet serving a small area in the transitional zone between the West Hill system and the Low Level system and 529 feet serving the West Hill system. Also, the City has a six million gallon storage reservoir with a water surface elevation of 416 feet, located at the intersection of James Street and 98th Avenue South, which supplies water to the Low Level system and serves as terminal storage for the Clark Springs transmission main. On Figure 11-1 is shown a topographic and service level map of the entire study area. On this map is shown the extent of the areas which can be served from the various service levels. These service levels can be varied locally as isolated circum- stances may dictate, but in general, show the areas which can be most effectively served from the respective areas . For satisfactory and reliable service, the working pres- sures in a water distribution system should fall within the range of 45 PSI minimum pressure to 100 PSI maximum pressure. 94 Converting the pressure differential of 55 PSI into feet of head, at the rate of 2. 31 feet per 1 PSI , would mean that an area with an approximate elevation differential of 125 feet could be served from any given storage elevation, without the use of pressure reducing valves. In small isolated areas, where it is economically impracti- cal to serve from an alternate source, or to develop a pressure reduced system, pressures slightly in excess of 100 PSI can be tolerated; however, the placement of pressure reducing valves for individual residences so served provides an economical and satisfactory method of controlling excessive pressures. EAST HILL SYSTEM The storage elevation for this system has been established at 590 feet. Since the maximum elevation served in this general area does not significantly exceed 500 feet, acceptable minimum pressures can be maintained, providing that proper provisions are made for storage and distribution. The area to be served from this system covers approximately eight square miles, being approximately two miles wide from east to west, and approximately four miles long fr om nort h to sou The existing storage reservoir is located in the extreme northerly portion of this area. At the present time, areas approximately two and one-half miles south of the reservoir are being served by this system. Porti ons of this southerly area have elevations in excess of 475 feet. An analysis of the East Hill system indi- cates that additional storage at the 590 foot dater surface ele- vation is needed in this southerly area in order to maintain ac- ceptable working pressures and to provide the storage required for the customers served. The service area of this system could extend to the 360 foot elevation contour without exceeding a sta- tic pressure of 100 psi. In the areas bordering the 485 foot ser- vice level, the boundary between the high and intermediate service levels can be varied considerably to accomodate local water main patterns. EAST HILL INTERMEDIATE SYSTEM This system was developed to provide service in the higher areas of the City of Kent. As these higher areas developed, and the demand for water increased, much of the subsequent supply and distribution facilities required to fulfill these needs were de- s.ianed and developed around this system. The storage for this level has a water surface elevation of 485 feet and serves the area lying between the 590 foot level and the 240 foot level. This service area in the transitional zone is limited by the topography of the area and only limited expansion is possible; however, some additional growth will occur as the population density increases. 96 From the standpoint of topography, the upper limit of this service level can be serv ed b th e 590 fo ot level where desirable. In the lower areas of the Intermediate System, an isolated pres- sure reduced system will be required to maintain service pressure within acceptable limits. The lower limits of the Intermediate system are presently being served through a pressure reducing valve. This pressure reduced zone should be expanded to some extent to include other areas which can be effectively served from the same system. { 416 FOOT STORAGE LEVEL The City of Kent presently has six million gallons of storage at this elevation. This storage reservoir is located at the inter- section of 98th Avenue South and James Street. No service level has been established at this elevation since the potential area which could be served from this level is presently being served from the 485 foot level. Due to existing water main locations, it is most advantageous to continue with the present method of service. LOW LEVEL SYSTEM The bulk of the area served by the Low Level system at the 240 foot elevation, is comfined to the valley floor. With adequate distribution lines, ample pressures can be maintained throughout the system. Although there is a small area which must be served in the transitional zone from the valley floor to the surrounding up- lands, only a limited need for water in the upper limits of the low level system is foreseen. Due to the rather precipitous na- ture of the hillsides surrounding the valley, only a limited amount of development can be expected in these upper areas. Elevations over the valley floor, which cover the majority of the service area, range from approximately 50 feet in the south to 20 feet in the north. Due to this relatively slight elevation dif- ferential and the ample size of the basic gridwork of the distribu- tion system, working pressures throughout the valley floor are quite uniform. WEST HILL INTERMEDIATE SYSTEM The topography of the West Hill System is generally quite simi- lar to that of the East Hill System. The area served by this system consists of an abrupt transitional zone from the Low Level System and a high plateau area containing the majority of the West Hill System. Storage for the Intermediate area of the West Hill System con- sists of a million gallon storage reservoir, serving a relatively small distribution system. The water surface elevation of this storage reservoir has been established at 354 .5 feet above sea level. 97 WEST HILL SYSTEM The water storage elevation for the West Hill System has been established at 529 feet above sea level. The storage reservoir for this system consists of a 300, 000 gallon elevated storage tank. A small area within this system with ground elevations of 450 feet must be served by the 529 foot service level. This elevation differential of 80 feet will yield only a static pressure in these higher areas of approximately 35 psi. The City is presently experiencing difficulties in maintaining sufficient pressure to the higher portions of the West Hill System. The computer analysis of this system indicates that pressures below 20 psi can be expected im the higher areas in periods of high usage . This problem is basically topographical with friction losses in the distribution system playing a somewhat minor role. Maximum pressures of approximately 110 psi can be expected in the lower limits of the West Hill System served from the 529 foot service level. While this pressure is considered excessive, it is anticipated that the areas so affected will be small, and limited in nature , and can be handled on an individual pressure reduction basis. 5 98 4 CHAPTER XII COMPUTER ANALYSIS OF EXISTING SYSTEM B ii CHAPTER XII R COMPUTER ANALYSIS OF EXISTING SYSTEM GENERAL In order to determine the capabilities of the existing dis- tribution system and to obtain information from which recommen- dations could be made for improvements required to meet existing and anticipated future demands , each separate system of the total distribution network was analyzed under various operating condi- tions . The initial analysis of these systems was made on the basis of peak demands for domestic, industrial and commercial usage, with no consideration given to the fire flow requirements . This was done in order to determine the location of areas where problems exist in providing normal peak usage, exclusive of fire flows . The anticipated flows were determined by applying the criter- ia developed and set forth in previous chapters. Fire flows used in subsequent computer runs were determined from known requirements at various buildings, such as schools and industrial installations. For the purpose of analyzing the adequacy of the existing distribution lines, the basic assumption was made that the quan- tity of water required to adequately supply these areas was available, and the water surface elevation in the reservoirs could be maintained within workable limits. As a practical matter, certain deficiencies exist in the area of supply and will be fur- ther discussed. The following discussions present the results of these com- puter studies and the conclusions drawn therefrom. EAST HILL SYSTEM The initial computer run of the East Hill System in which no fire demand was considered, indicated that this system as presen- tly constituted is capable of supplying the flow required for a peak day usage, and adequate pressures can be maintained. In the area north of South 240th Street, which is served by a well-gridded distribution network, line losses due to friction are minimal . While adequate flows can be provided in the southern portion of the service area, working pressures of 40 to 45 psi can be expected during peak usage days . While this situation is basically attributable to the elevation of the area served, a lowering of W these working pressures can be expected as the demand for water in this area increases with development. 100 At this time, it should be pointed out that the maximum static pressure available in this area is approximately 48 psi . Through a comparison of these pressures it is apparent that line losses to this area are relatively small, pointing to the fact that the ultimate solution to maintaining adequate pressures in the southerly portion of the system can be accomplished most readily by the installation of an additional storage reservoir in the immediate vicinity. Also, an analysis of the population figures and fire flow requirements for the East Hill area indicate a:: Existing storaqe deficiency of approximately 1. 5 million qallons. A second run was made of the East Hill System, assuming a 12-inch main on 116th Ave. S .E. , south of Kent-Kangley Road, with a fire flow of 1 , 000 gpm taken out in the Derbyshire area. The results of this run indicated that a flow of this magnitude cannot be provided in this area under present conditions. As previously discussed , the fire flow requirements at the various schools located within the East Hill System service area represent the extreme demand which will be placed on the system. In view of this , a third run was made assuming a fire at the Park Orchard School. This school , located north of Southeast 232nd Street between 110th and 112th Avenues Southeast, is the most advantageously located of these schools from the standpoint of proximity of supply, and is served by some of the larger lines within the system. The results of this run indicated that a flow of 3, 000 gpm with a residual pressure of approximately 30 psi could be provided at the Park Orchard School from the existing system, in. addition to providing the flows required for a peak day ' s usage. At this flow rate , acceptable pressures can be maintained throughout the remainder of the system; however, residual pressures in some localities would be approaching the acceptable minimum. From a comparative analysis of the results of these three runs, it was readily apparent that the required fire flow could not be completely supplied at any of the other schools served by the East Hill System. In .view of this , no additional runs were made of the existing system. In order to determine the improvements required to adequately provide for present and future demands , additional runs were made using flows based on population increases as determined in Phase I of the comprehensive study , and an expanded service area. Recom- mended improvements , and the timing and cost estimates of these improvements , are discussed and summarized in a following chapter. EAST HILL INTERMEDIATE SYSTEM The supply for this system is obtained from the 485 foot level elevated tank at James Street and 98th Avenue South. This service 101 i, II level presently consists of a number of smaller systems. Since it is anticipated that these smaller systems will be consolidated for simplification of operation, no computer analysis was made of the Intermediate System as it is presently operated. A convention- al analysis was made of the system and a system of improvements derived therefrom. The capacity of the elevated tank is 125 ,000 gallons and is supplied by gravity from the Clark Springs Transmission Main. Under gravity conditions to the 485 foot level, the potential capa- city of the Clark Springs Main is reduced. to approximately 65% of the gravity flow which can be supplied to the 416 foot elevation, six million gallon reservoir located on the same site. Since water for the East Hill System is also pumped from the 485 foot level, the flow from the Clark Springs Main is substantially re- duced much of the time. As the demand for water increases in the areas supplied from the Clark Springs Main, this throttling effect becomes more serious. In view of this, the Clark Springs Main should discharge di- rectly into the six million gallon reservoir on South 240th Street, and the water required to supply the East Hill Intermediate and High Level Systems should be pumped from this terminal storage. In general, the intermediate system is adequately gridded and will require only minor line installations to adequately serve . the potential service level. Since the elevation range from the 485 foot water surface to the upper limits of the low level system, has a pressure differential of approximately 150 psi, it will be necessary to serve the lower limits of the in- termediate system through pressure reducing valves. LOW LEVEL SYSTEM In the analysis bf the low level system, two computer runs were made. The first of these runs was made using a peak demand of 3,780 gpm for domestic, commercial and industrial usage. Also, a flow of 900 gpm for supply to the West Hill System and a fire flow of 1,000 gpm were assumed. The results of this run indicated that the low level system has sufficient capacity to provide this flow with very minimal head losses due to friction. Since it has been determined that certain areas within the low level system will require a fire flow of 5 ,000 gpm an addi- tional run was made using this demand plus the flow of 3,780 gpm required for a peak usage day. In this run, it was assumed that pumping to the West Hill System could be temporarily suspended to aid in providing the flow required for a fire of this magnitude. 102 The location of this fire was assumed to be in an area where an extreme flow condition would be simulated. This flow was taken from the system on the 16-inch line running between South 180th Street and the East Valley Highway, along the easement on the east side of the Pacific Intermountain Express property. This area is presently served by a single 16-inch line. A study of the results of this run indicated that the present distribution system is capable of supplying this peak day demand, and can also produce a fire flow of 5 ,000 gpm in the area consi- dered. In addition to maintaining acceptable residual pressures for satisfactory service, a residual pressure of approximately 23 psi can be maintained at the point where the fire flow was with- drawn. In comparing the critical nature of the area in which the fire flow was withdrawn, to other areas of the low level system which are presently supplied from a gridded system, it was appar- ent that the existing low level system could supply a fire flow demand of this magnitude to the areas where fire flows of this quantity are required. Tests conducted by the Surveying and Rating Bureau indicated that a fire flow of 4275 GPM with a residual pres- sure of 20 psi can be supplied in the main mercantile area of the City. The required fire flow in this area has been established r by the Bureau as a part of a survey of the entire fire protection system of the City of Kent completed on April 1 , 1970. In addition to the two initial computer runs on the existing system, an additional run was made on the basis of future popula- tion projections. While it is not possible at this time to pre- dict with accuracy the manner in which demands in the low level system will develop, certain recommendations as to minimum line sizes and interconnections which should be anticipated, were de- veloped from an analysis of the results of this computer run made on the basis of probable future demands. Also considered, were the effects of isolating certain portions of the distribution sys- tem for supply from the City of Seattle. WEST HILL INTERMEDIATE SYSTEM Storage for this system consists of a one million gallon ground storage reservoir with a water surface elevation of 354 feet above sea level . The area served from this system is quite limited in extent at the present time. Considering the topography of the area served, the extent of this distribution network and the quantity of storage available, it is readily apparent that with the exception of the pumping facility, this system is quite adequate for the foreseeable future. An analysis was made for the determination of future improvements. 103 WEST HILL SYSTEM In the analysis of this system, certain observations were made regarding topography, line sizes and locations and storage, which indicated that pressure and supply problems could be ex- pected during times of normal peak usage. In view of this, a computer analysis was made of the existing system, in which a fire flow was not considered. The results of this run indicated that in the area west of 40th Avenue South, and north of South 256th Street, pressures ranging from 20 to 30 psi can be expected during periods of high demand. Ground elevations in this low pressure area range from ap- proximately 425 feet to a maximum of 450 feet above sea level. In evaluating this information, it can be seen that the maximum y static pressure available to this area ranges between 35 and 45 psi . Since the storage reservoir serving this area is located in the southerly portion of the West Hill System, cumulative line losses due to friction result in service pressures substantially below the minimum considered acceptable. The problem is basically topographical in nature, and increasing supply line sizes within the limits of economic feasibility, is not a practical solution. Since the 529 foot service level is presently deficient in storage, acceptable pressures could be maintained and the required storage provided, by the placement of an additional storage reser- voir in the northerly portion of the system. Also, since almost continuous pumping operations are required to supply the West Hill area during peak usage days , an additional pumping capability should be provided. ti 104 CHAPTER XIII COMPREHENSIVE PLAN AND COST ESTIMATES a CHAPTER XIII COMPREHENSIVE PLAN AND COST ESTIMATES The water system improvements for the City of Kent presented in this chapter are . concerned with all aspects of water transmis- sion, storage and distribution. Facilities were planned on the basis of developing new sources and purchasing water from the City of Seattle as presented in Phase I of this report. Trans- mission and major distribution pipelines and storage reservoirs. are shown on Figures 13- 1 through 13- 5 of the comprehensive plan. Transmission and distribution pipelines were planned to pro- vide for maximum development based on population projections h the year through 2000 and reservoir capacities are based on 1985 population projections . Priorities for scheduling proposed facil- ities were established on the basis of present needs and on anti- cipated needs through 1967 . These priorities are also based on the sequence of developing new sources and purchasing water as presented in Plan A of Phase I of this report, with the exception of serving r the West Hill System with water purchased from the City of Seattle as soon as possible . If the sequence of developing new sources and purchasing water is varied, the priorities established may change. EAST HILL SYSTEM The East Hill System is presently served by the Park Orchard pump Station which pumps from a 125,000 gallon reservoir serving the East Hill Intermediate Level System. The comprehensive plan includes two new pump stations to serve the East Hill System as shown. One proposed pump station will pump from the existing six mil- lion gallon reservoir supplied by the Clark Springs Transmission Pipeline and the other will pump from a proposed 2 .5 million gal- lon reservoir located east of 98th Avenue South , south of the Scenic Hill Elementary School to be fed by a proposed transmission pipe- line from Kent and Armstrong Springs. This transmission main is proposed when additional supply is developed at Kent Springs or Armstrong Springs. Under gravity conditions , this transmission main will discharge only to Low Level System. Pumping facilities will be required at the source to discharge into the proposed 2 .5 million gallon reservoir at elevation 485 . From the 2 .5 MG reser- voir, a proposed pump station will discharge into the East Hill System. A five million gallon standpipe to be located north of South- east 270th Street , west of 118th Avenue Southeast, is planned for the East Hill System. Sufficient property to allow for additional 106 future storage should be acquired as a part of the site for this proposed standpipe. The site of the existing one million gallon standpipe on 112th Avenue S. E. , north of S . E. 240th St. , is suf- ficiently large to allow for the placement of additional storage. v Pipelines proposed within the East Hill area include both transmission and distribution pipelines . At such time that addi- tional sources are developed at Kent Springs or at Armstrong Springs, a transmission pipeline will be required to transport this water to the service areas . This pipeline will provide water to the East Hill and East Hill Intermediate Level System. An exten- sion of this pipeline also will transport water to the Low Level System. Distribution pipelines within the East Hill System include a large pipeline connecting the proposed pump stations with the proposed five million gallon reservoir and smaller pipelines to provide for adequate domestic service and fire protection through- out the area. On the eastern limit of the East Hill System, the City and Water District No. 111 have agreed on 124th Ave. S. E. as a com- mon boundary line. To avoid a duplication of mains on this street, close coordination of these entities will be required. Since 124th Ave. S. E. is a major arterial, it will probably be advantageous to locate mains on interior future streets as they develop, rather than on the arterial. EAST HILL INTERMEDIATE SYSTEM This system provides service to a relatively narrow strip of land along the east side of the Kent Valley which is above the Low Level System and below the East Hill System. A 2. 5 million gallon reservoir east of 98th Avenue South, south of the Scenic Hill Ele- mentary School, is proposed to augment the existing storage within the service level. A 12-inch pipeline to connect this reservoir to the existing distribution pipelines, and several smaller pipe- lines connecting portions of the existing distribution system, are also proposed for this system. A pressure reducing valve station, a small reservoir and manu- ally controlled valves provide reduced pressures to customers at lower elevations within this system at the present time. A pro- posed pressure reducing valve station in the vicinity of Temper- ance Street and Alvord Avenue to be operated in conjunction with the existing pressure reducing valve station will provide more reliable service to the lower elevations and will not require con- stant adjustment by water department personnel. Sufficient area is available at the reservoir site on James Street and 98th Avenue for the placement of additional storage as required for the East Hill Intermediate System. Pumping facilities to serve this area should include a pump 107 station with a capacity of approximately 1000 gpm to pump from the existing six million gallon reservoir north of James Street and west of 98th Avenue South. At the time this station is con- structed, the initial stages of the proposed East Hill System pump station pumping from the six million gallon reservoir should be constructed and the Park Orchard Pump Station should be taken out of service. The Clark Springs Transmission Pipeline will gravity only about 65 percent of its capacity into the 125 , 000 gallon reservoir at elevation 485; therefore, until the above steps are taken, maxi- mum utilization of this source cannot be realized. LOW LEVEL SYSTEM The Low Level System provides service to the central business district, the industrial area to the north and to other customers within the Kent Valley. King County Water District #87 to the south, also receives water from this system. The existing three million gallon Scenic Hill Reservoir and a six million gallon re- servoir being constructed along South 218th Street are anticipated to provide sufficient storage for this system through 1985. Distribution pipelines proposed within this system include a 16-inch pipeline connecting existing 16-inch pipelines near the new six million gallon reservoir and several 10-inch through 16- inch pipelines throughout the Low Level Service area to provide for continued development. Three connections to the proposed City of Seattle transmission pipeline and reservoir are planned to provide for service as re- quired in the future. These proposed connections include one at South 212th Street and 84th Avenue South to connect to a 16-inch pipeline, another at South 228th Street and 68th Avenue South to connect to a 16-inch pipeline and a third in the vicinity of the Kent-Des Moines Road. This connection would flow into both the Low Level System and the West Hill Intermediate System through a 16-inch pipeline and through separate control valves. WEST HILL INTERMEDIATE SYSTEM The existing storage and distribution facilities within this system are anticipated to provide adequate service throughout the period of time covered in this study. If development occurs in areas not presently developed, the distribution system should be expanded; however, present storage is anticipated to be sufficient. +, At such time that water service from the City of Seattle is avail- able, a connection to this system should be constructed as previous- ly described. Prior to connection to the City of Seattle pipeline, however, the capacity of the pump station pumping into this system should be increased. 108 WEST HILL SYSTEM This system provides service to an area west of the Kent Val- ley bounded on the west by Interstate Highway No. 5 and on the north and south by areas served by King County Water District # 75. Water for this system is pumped through the West Hill Inter- mediate System from the Low Level System. Proposed improvements for the West Hill System include a one million gallon standpipe to be located in the vicinity of South 244th Street and 37th Avenue South near the City of Seattle's pro- posed reservoir and additional distribution pipelines to provide for increased service and fire fighting. The capacity of the ex- isting pump station serving this system also must be increased to provide sufficient quantities of water. If an economical reservoir site is not available near Seattle' s proposed reservoir, additional storage should be constructed in the vicinity of the existing West Hill reservoir and a 12-inch pipeline should be constructed from the existing reservoir site to the intersection of South 243rd Street and 37th Avenue South to provide for adequate domestic ser- vice and for fire demand. COST ESTIMATES An engineering study concerned with the problem of developing a long-range program of water system improvements requires the pre- paration of cost estimates for construction of proposed facilities. It is necessary to evaluate alternative projects and stages to de- termine the feasibility through cost analysis. Cost estimates involve a judgment factor based on experience, but construction costs may swing in a wide range because of vari- able factors which cannot be predicted, such as labor availability, competitive conditions, management, mechanization and many other intangibles affecting construction costs at the time the work is actually performed. Generally, actual costs cannot be known until bids are received and even these may be subject to adjustment be- cause of changed conditions . The engineers use their past experience and best judgment in preparing cost estimates, but because of the impossibility of pre- dicting variable and intangible factors, cannot and do not repre- sent nor guarantee that the work can be performed for the estimated cost. The City in its decision making, must always keep in mind that an estimated cost is the engineer' s best opinion, not the ulti- mate fact of cost. z 109 Construction Costs Construction costs are estimated from prices obtained from various sources, including manufacturers and suppliers of mater- ials and equipment and other communities in the area. In consi- dering these estimates it is important to realize that changes during final design quite possibly will alter the totals to some degree and future changes in the cost of material, labor and equip- ment, will have a direct bearing on costs presented. Construction costs have shown a general upward trend over the years as indicated by the Engineering News Record Cost Index. This index begins with a base of 100 for 1913 and has climbed at an average of 5. 5% per year since 1931. Costs used in this report are based on an Engineering News Record Cost Index of 1540 at the end of 1971. The estimated costs developed in this study will have to be adjusted in accordance with the projected index for any construction subsequent to this time. Project Costs In the preparation of the comprehensive plan, cost estimates were developed to evaluate alternative projects and stages . These estimates are presented in the following tables. Table 13=1 in- cludes project cost estimates for Stage One facilities that are proposed for construction within five years . Pipelines included in this table are listed in the order of priorities established for construction of these facilities . Table 13-2 includes pro- ject cost estimates for all proposed facilities included in the comprehensive plan. In addition to the cost of construction, project costs include allowance for taxes, engineering, financial and legal services, in- terest during construction, discount, bond printing and adminis- trative costs. In this report, 35 percent was used for these items to compute total project cost. The staging of additional improvements is contingent upon fu- ture growth in the area and upon the formation of local improvement districts in accordance with the wishes of the concerned property owners. 110 TABLE 13-1 STAGE ONE PROJECT COSTS EAST HILL SYSTEM Pipe Estimated Size On From To Project Cost 12" 116th Ave. S .E. Kent-Kangley S .E . 280th St. $105, 000 Extended Rd. 18" City property Proposed Pump James St. 17, 000 & 98th Ave. S.E . Station 18" 98th Ave. S . James St. S.E. 244th 35, 600 extended 18" S.E. 244th St. 98th Ave. S. 100th Ave. S.E. 18, 900 extended 16" S .E. 244th St. 100th Ave. SE 104th Ave. S.E. 32, 000 12" 104th Ave. S .E. S .E. 240th St. S .E. 244th St. 23,200 10" 104th Ave. S .E. S.E. 244th St. S .E. 264th St. 90 ,000 8" Esmt. 300 ' S . 100th Ave. SE 700 ' W. of 104th 7 , 600 of S. 252nd St. Ave. S.E. 12" Esmt. 300' S. 100th Ave. SE 500 ' W. of 100th 8,700 of S. 252nd St. extended Ave. S .E. 12" Esmt. 500 ' W. of 300 ' S. of S. Kent-Kangley Rd. 10,600 100th Ave. S.E. 252nd St. extended 12" 98th P1. & 100th Kent-Kangley S.E. 264th St. 69 , 200 P1. (Crow Road) Rd. 16" S.E. 264th St. 98th Ave. S .E. 116th Ave. S.E. 145,500 & S.E . 264th extended extended 16" S .E. 270th St. 116th Ave. SE 600 ' E. of 116th 14, 600 extended Ave. S .E. extended 8" Kent-Kangley Rd. 500 ' W. of 200 ' W. of 100th 3, 200 100th Ave. S. Ave. S. extended extended ill EAST HILL SYSTEM (Cont. ) Estimated Project Cost Storage Reservoir Five million gallon standpipe (1. 8 million gallons at service level) located north of S . E. 270th St. and west of 118th Avenue S. E. $589,000 Pump Station *Two thousand gallons per minute (7500 gpm ulti- mate capacity) pump station located adjacent to existing six million gallon reservoir north of James Street and west of 98th Avenue South. 63,400 EAST HILL INTERMEDIATE SYSTEM Pipe Estimated Size On From To Project Cost 12" Woodland Way S . 257th St. S . 264th St. $ 50, 000 10" Woodland Way S. 257th St. Walnut Street 5,500 8" 98th Ave. S. S . 243rd St. S. 248th St. 18, 500 8" S. 248th St. 97th Ave. S . 98th Ave. S. 3,600 8" Esmt. 450 ' E. of Smith Street Kensington Ave. 7,600 Titus St. I 6" Reitan Road Kensington Ave.400 ' E. of Kensing- 3,400 ton Ave. 6" Van De Vanter 200 ' N. of Walnut Street 1, 700 Ave. Walnut St. 6" Walnut Street Van De Vanter Alexander Ave. 2,500 Ave. 8" Kent-Kangley Smith Street Crow Road 45, 500 Rd. & Alvord Ave. Storage Reservoir Two and one-half million gallon standpipe (1, 250, 000 gallons at service level) loca- ted east of 98th Avenue S. and south of S.E. 264th Street extended. 314 , 400 112 EAST HILL INTERMEDIATE SYSTEM (Cont. ) Estimated Project Cost Pump Station *One thousand gallon per minute pump station located adjacent to the existing six million gallon reservoir north of James Street and west of 98th Avenue South. $ 27 ,400 *These two pumping facilities can be instal- led in one building with a common supply from the 6 MG Reservoir at elevation 416. Pressure Reducing Valve Station Pressure reducing valve station along Alvord Avenue, north of Temperance Street 7 ,600 LOW LEVEL SYSTEM Pipe Estimated Size On From To Project Cost 16" S. 212th St. 84th Ave. S. 400 ' E. of $108,600 Extended 92nd Ave. S. 10" Frontage Road S. 218th St. S . 228th St. 59,000 E. of Valley Freeway 10" James St. Russell Road 64th Ave. S. 40, 800 10" 80th Ave . S. S . 194th St. S . 196th St. 12, 700 12" 80th Ave. S. 900, S. of S. S . 188th St. 44, 000 180th Street 12" S. 188th St. 80th P1 . S. 80th Ave. S. 19 , 800 12" 79th Ave. S. & S. 258th St. S . 266th St. 62,500 80th Ave . S. 12" S . 266th St. 79th Ave. S. 700 ' E. of 15 , 500 79th Ave. S . 12" West Valley Rd. Kent-Des Moines S. 262nd St. 125, 000 Road 12" S. 262nd St. West Valley Rd. Valley Freeway 21, 800 113 LOW LEVEL SYSTEM (Cont. ) Connection to Seattle Pipeline Meter and connection to City of Seattle transmission pipeline in the vicinity of S. 212th Street and 84th Ave. S. (Includes pressure reducing station) $ 31, 300 WEST HILL INTERMEDIATE SYSTEM Pipe Estimated Size On From To Project Cost 16" Kent-Des Moines Proposed Seattle 48th Ave. S. $ 59 ,200 Road Pipeline Connection to Seattle Pipeline Meter and connection to City of Seattle S 29 ,700 transmission pipeline along the Kent-Des ti Moines Rd. (Includes pressure reducing station) Pump Station Modifications Modify existing pump station located in the vicinity of 48th Avenue So. (Reith Road) and Kent-Des Moines Road, by ad- ding existing pump from station along 42nd Avenue So. New capacity to be approximately 1500 gpm. $ 16,600 WEST HILL SYSTEM Pipe Estimated Size On From To Project Cost 10" Easement Elevated Tank Hampton Way $ 2, 700 S . 265th St. 8" - Hampton Way Easement .Manchester Ave . 6, 500 Storage Reservoir One million gallon standpipe (400, 000 gallons at service level) located in the vicinity of 37th Ave. S . (Military Road) and S. 244th Street. $189,500 114 ti WEST HILL SYSTEM (Cont. ) Pump Station Modifications . Modify the existing pump station loca- ted along 42nd Ave. S. to increase the capacity to 2000 gpm by replacement of existing pump and addition on one new pump. 38 , 300 Water Source Improvements Chlorination facilities at Kent Springs 25,900 Total Estimated Project Cost $2, 630, 600 A, x 115 TABLE 13-2 PROJECT COST ESTIMATES FOR COMPREHENSIVE PLAN Estimated Feet of Pipelines Project Cost y 2 , 880 - Six Inch Mains $ 24 ,500 93,150 - Eight Inch Mains 1 ,048,000 80, 100 - Ten Inch Mains 1 ,205 , 000 155 , 300 - Twelve Inch Mains 3 ,130,000 i 1,600 - Fourteen Inch Mains 33 ,200 11, 300 - Sixteen Inch Mains 276 ,000 2 ,400 - Eighteen Inch Mains 65,000 45 ,000 - Twenty-four Inch Mains 1 ,710 ,000 Sub-Total $7 , 491 ,700 F > Storage Reservoirs Five million gallon standpipe for East Hill System (1. 8 million gallons at $ 589,000 service level) Two and one-half million gallon stand- pipe for East Hill Intermediate System 314,400 (1,250, 000 gallons at service level) One million gallon standpipe for West Hill System (400 , 000 gallons at ser- 189 ,500 vice level) ` Sub-Total $1 ,092,900 i pump Stations 7500 gpm pump station for East hill System $ 151,400 4500 gpm pump station for East Hill System 71,600 1000 gpm pump station for East Hill Intermediate System 27 ,400 Modification to existing West Hill Pump Stations 54 ,900 y Sub-Total $ 305,300 116 s TABLE 13-2 (Cont. ) Estimated Miscellaneous Projected Cost Three Connections to City of Seattle Pipeline and Pressure Reducing Valve Stations $ 92 ,300 Pressure reducing valve station 7,600 Chlorination Facilities at Kent Springs 25,9,00 Abandon 114th Ave. S .E. Open Reservoir City Forces Sub-Total $ 125,800 TOTAL ESTIMATED PROJECT COST $ 9 ,015 ,700 I �I i r. 117 a APPENDIX CITY OF SEATTLE WATER RATES TO PURVEYORS --he following charges were recommended in a recent study prepared by the City of Seattle Water Department and will become effective as indicated. These rates supercede the rates listed in Chapter VII , Phase I , of this report, and will apply to any water purcha- sed by the City of Kent. Basic Rate (effective October 1, 1970) 13 . 5(� per 100 cubic feet Meter Charge (effective January 1 , 1971) Applies to connections to City of Seattle facilities . Meter Size Monthly j (Inches) Charge 1 . . . . . . $ 10 . 00 1 1/2 . . . . . . . . . 15 . 00 2 . . . . . . . 20 . 00 3 . . . . . . 25 . 00 4 . . . . . . . 35 . 00 6 . . . . . . . 60 . 00 8 . . . . . . 70 . 00 8 x 4 . . . . . . 80 . 00 10 x 6 . . . . . . . . 100. 00 10 x 12 x 6 . . . . . . 110. 00 12 . . . . . . . . 130 . 00 Ordinance No. 99109 approved by the City of Seattle on July 23 , 1970 , contains the above rates and is a part of this Appendix. ORDINANCE 99109 V; ORDINANCE relating to the municipal water supply system of the City and amending Sections 33 and 34 of Ordinance 65877 , as amended. BE IT ORDAINED BY THE CITY OF SEATTLE AS FOLLOWS : Section 1. That Section 33 of Ordinance 65877 , as last amended by Ordinance 85105 , be and it is hereby amended as follows : Section 33. That as of October 1 , 1970 all water used for domestic and commercial purposes shall be supplied by meter only at the following rates and charges . The rates for metered water supplied to premises within The City of Seattle in one month, or fractional part thereof , shall be in accordance with the following schedule : Consumption Service Size Quantity Allowed Minimum Charge - I 3/4 inch 300 cu. ft. $ 1 .50 1 600 it1.95 1-1/2 " 1200 it2 . 85 2 2000 it 4 . 05 3 3400 6 . 15 4 4900 8 . 40 6 7100 " 11.70 8 10000 16 . 05 10 14000 22. 05 12 20000 31. 05 Each 100 cubic feet in excess of the quantities allowed for the foregoing minimum charges except as hereinafter provided $ . 15 Each 100 cubic feet in excess of the first 30 ,000 cubic feet. . . 10 v Each separate building or premises in addition to the first or principal building or premises supplied through the same service connection , 500 cubic feet or less . . . . . . . . . . . . . 1 .70 Provided, that the terms "separate building or premises" shall not apply to trailer parks or trailer courts , which shall be governed as to water rates by the number and sizes of services and -uantity of water used under the previous schedule . ;rater supplied to the City Lighting Department and to the i Seattle Transit Commission, each 100 cubic feet in excess of the quantity allowed for the foregoing minimum charges . . . . . . . . . .$ . 10 The rates for water supplied for fire protection purposes exclusively shall be deemed service charges and shall be for any one month, or fractional part thereof, as follows : Size of Service Service Charge 2 inch $ 1 .85 3 2 .75 4 3 . 90 6 5 .40 8 7 . 10 10 9 .75 12 11.70 The service charges hereinabove set forth shall be granted only during such times as there is no appreciable registration by the meter maintained by the City on such fire protection services . Water used for any other purpose than for extinguishing fires , through a fire protection service , shall be charged at a rate double the common rate provided for in this ordinance . -2- v Section 2 . That Section 34 of Ordinance 65877 , as last amended by Ordinance 85105 , be and it is hereby amended to read as follows : Section 34 . That as of October 1 , 1970 except as otherwise hereinprovided, the rates for metered water supplied to premises not within the limits of The City of Seattle shall be for one Month, or fractional part thereof, in accordance with the following schedule : Size of Service Allowed Quantity Minimum Charge 3/4 of an inch 300 cubic feet or less $ 2 . 25 1 inch 600 2 .90 1-1/2 inch 1200 4 . 25 2 inches 2000 6 .00 3 3400 9 . 20 4 4900 12 .60 6 7100 17. 55 8 10000 24 . 05 10 14000 33 .25 12 20000 46 .60 Each 100 cubic feet in excess of the foregoing minimum charges , except as hereinafter provided. . . . . . . . . . . . . . . . . . .$ . 23 Each 100 cubic feet in excess of the first 30 , 000 cubic feet per month. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Each separate building or premises , in addition to the first or principal building or premises upplied through the same service connection, 500 cubic feet or less . . . . . . . 2 .55 -3- Each 100 cubic feet in excess of the first 100 , 000 cubic Y feet when directly supplying a manufacturing or industrial operation located in areas adjacent to the Cedar River transmission mains between the bake Youngs Control Works and the southerly City limits , $ . 12 ; Provided, however, that as of October 1 , 1971 such rate shall be $ . 13, and that as of October 1 , 1972 the rate shall be $ . 14 , and as of October 1, 1973 the rate shall be $ . 15 . i That the rates for water supplied for fire protection purposes j exclusively shall be deemed service charges and shall be for any one month , or fractional part thereof, as follows : Size of Service Service Charge 2 inch $ 2 .75 3 4 . 15 4 5 . 85 6 8 . 10 8 10 .65 10 14 .65 12 17 .55 The service charges hereinabove set forth shall be granted only during such times as there is no appreciable registration by the meter maintained by the City on such fire protection services . Water used for any other purpose than for extinguishing fires , through a fire protection service , shall be charged at a rate double the common rate provided for in this ordinance . IL -4- The rate to be charged municipal water districts and other municipalities authorized to and engaging in the distribution of water under the laws of the State of Washington and where such districts and municipalities operate , maintain and distribute water for resale purposes through a master meter furnished by the City of Seattle , shall be as follows : $ . 135 per 100 cubic feet for all water furnished. That as of January 1 , 1971 the following meter charges with respect to such districts and municipalities shall be imposed: t Meter Size Monthly Charge 1 inch $ 10.00 1-1/2 inches 15 .00 2 inches 20 . 00 3It 25 .00 4if 35 .00 6 60. 00 8 70 . 00 8 x 4 inches 80 . 00 10 x 6 inches 100 .00 10 x 12 x 6 inches 110 . 00 12 inches 130 . 00 Section 3. That imposition of the rates and charges here- inabove set forth as of October 1, 1970 , and any other act pursuant to the authority and prior to the effective date of this ordinance are hereby ratified and confirmed. r Approved July 23 , 1970 Eff. 30 days -5- .-L!kTER SAMPLE INFORMATION FOR CHEr-"AL ANALYSES I.D. \-,NeFR COUN•IY o111:TY No COLLECTF.11 BY King — 1 7 B. Hansen (TI?!`: COLLE:'TF.D PATE LAST SAMPLE. ITAKEN DrtMe (❑F^'-•AFT . -�-r 9.15 Art F �' ROM STORAr..F TANK l-]UYUWANT - - l r -�------- -------- -- ------- ------.-_-.- --L - - �` --------- 1. COI.I.FCTED FROM PullLIC WAI ER 00THYR (Specify 31FL1. SAMP - — I 114th Ave. Reservoir '1 SPRIN(..,Clark _ _ - FIF - TFNMLkT:�1-r ALKALINITY THIS WATER IS FILTERED RFatARKS OVN7RGTt:p l7IRFR TRFATMEtiIFI11AY7tP ---- K. Evenson State of Washington Kent Water Department pep,artrient of Social cnd i°_a:th Sc-:ice Clty Hall — DIVISICIN OF — - - - - --- Smith Tower Seattle, Was',irftcn 9F: Kent Washington 98031 (C i t y�) - ----- (zip) -- i ---_ Inc/1 -=—. -- ----- imE/1 -- ---- - 3Bicarbonate -- Q!CO3) 51 .24 AL-+ter (Al)�- Carbonate (CO3) Ircn — (`e) None Chlorine 0.5 01n) C1?� .009 _ Sulfate <so. 8.3 I •O5 Sulfite (S03) Chloride 5 .14 CAlcl= (Ca) 12.0 .60 Fluoride tl) .8 •LZ+ - - --- Nitrate (NO3) as Nftn;i;cq 00 1.0 .07 - - ---- -- Nitrite 002) �ns Nitrogen (N) .013 Phosphate (Y0i) .67 •H- 05 TOTAL 1.47 TOTAL 1.21 P11, Lab --- uspeodrd Solid: ------—.- ..- - Dissolved Solids - Nfcr,-+m!ins/cT+, 2_'C) 7oti O la 12 Tutbidity 0TU) - - - - -----------" 4 }Total Solids - 74 _ c Color (units) 3 Total Hardness (CAtS)3) 6 + Nt r (thresh_ld cilutlan factor) Alkalinity (Caw)) 42 (Slight chlorine) _ Taste (threshold d.lu.trn [A:rnT) 4 Noncarbonate hardnesa (Ca(7)3) 2 2 4Free CO2 (mf/1) h 4 Calcitmt hardness (Ca()3) 30 - 4Kagnesium hardness (CaOD)) 34 4Calculated hardness (Ca003) DATE RECEIVED DA1'C CQ1PLUED CQIPLE'TFD BY 1.AB NO, 1-4-72 1-4-72 JS OW 906 mg/1 . ppm (part* per million) - - — -------- - --- m«/i . rpm (.gnivnlents per aillion) REA-L- A(It-11 6 71. `iConverted to Cof when calculating total sollda 4 Calculated values ' COMM on,LY NO COLLECTED BY �1 T7 B. Hansen Ile OTK�R -:- -- -----T----- �ALI—A AIMPLF TAKEN C3r',MP FAUCEr K. Ev ison State of Washington Servicvs Ker.t Water Department Departmilt. of nn� Health city Hall DIVISION OF J!-ALTH Washington 98031 PER SAMPLE INFORMATION FOR Cliht AL ANALYSES 63-44 Carbonate (CO3) Chloride 6.5 hosphate Otago TOTAL 1.82 TOTAL 1 .72 uspended Solidi / � � v | ----_� / | * --------�� / . P11 "" 7 .0 Dissolved Solids con_--' Odor (thresh Nil Alkall-ItY (CaCO3) 52 | m (threithold ^^^``^~^ factor)-- 4Free m ~n/v 1-5-72 is OW 905 � 2 ° — In determining the cost of water under Plan B, the Ranney Well was considered as one project and Kent Springs, Armstrong Springs , and Covington were put together as another project. The unit cost of water for these projects is shown in Table 7-6 . TABLE 7-6 UNIT COST OF WATER - PLAN B Ranney Well 13.00/100 cubic feet Kent Springs 13. 1G/100 cubic feet Armstrong Springs & Covington The cost per cubic foot as shown in Table 7-6 is based on the projected facility life and cost estimates contained herein t and are therefore more properly termed projected unit water costs . Because the bond issue maturity schedule may not coincide with the expected facility life, unit costs in Table 7-5 are not necessarily indications of potential monthly user costs. Table 7-5 and Table 7-6 concludes that water will be avail- able at approximately the same cost by either plan. The cost of 12 . 2�/100 cubic feet for Seattle water in Plan A is based on the current Seattle water rate for the year 1976 when the Kent Valley, West Hill and all low level areas below those reservoirs would be served with water purchased from Seattle. If, due to the rate structure review, Seattle raises the water rate the 12 . 2�/100 cubic foot rate would increase proportionally. On the other hand, as the quantity of water purchased from Seattle increases , the overall rate would decrease. A long-range comparison of unit water costs of Plans A and B is difficult at this time, since the City of Seattle is presen- tly in the process of a cost and rate study. A rate structure analysis making a comparison of these plans , considering Seattle.'s new rates , should be made by the City of Kent. This analysis. should, of course, also include the. effects of the projected bond issues on the water rates. t 62 Figure 7-1 PLAN A SERVICE AREA Supply vs. Demand 100 50 Total eak --- ---- ----- -flail j----- Peak supply 20 • a a ♦♦ e 1 ♦ 6 10 ec 5 Peak daily demand ^1 on lent resources c ` 1 1960 1970 1980 1990 2000 Year Note: 1. Numbered ordinates to correspond to numbered items listed under Plan A development. 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