HomeMy WebLinkAboutPW07-148 - Amendment - #7 - The City of Tacoma - The Second Supply Project Partnership Agreement - 09/10/2010 AMENDMENT NO. 7 TO
SECOND SUPPLY PROJECT AGREEMENT
BETWEEN
THE CITY OF TACOMA, DEPARTMENT OF PUBLIC UTILITIES,WATER
DIVISION,
THE CITY OF KENT,
COVINGTON WATER DISTRICT, AND
LAKEHAVEN UTILITY DISTRICT,
THIS AMENDMENT is made and entered into effective this day of , 20_,
between the City of Tacoma, Department of Public Utilities, Water Division (Tacoma);the City
of Kent(Kent), Covington Water District(CWD), and Lakehaven Utility District (Lakehaven),
collectively the Participants; and
WHEREAS,the Participants entered into the Second Supply Project Agreement(Agreement)on
December 19, 2002; and
WHEREAS,the Second Supply Project includes municipal water storage behind Howard
Hanson Dam for the Participants as described in Sections 19 and 20 of the Agreement; and
WHEREAS, Section 20.5 of the Agreement requires Tacoma to transmit to each of the
Participants a report regarding the status of operations related to the Project by means determined
by the Project Committee and further allows the Project Committee to revise the information to
be included in the weekly report by Tacoma, and
WHEREAS, Tacoma, as the operator of the Second Supply Project,has captured project water
storage availability, allocation, restrictions, scheduling, use and management in the Tacoma and
Second Supply Project Operations Report(Operations Report); and
WHEREAS, the Operations Report is available to the Participants online on a website accessible
to Participants; and
WHEREAS,the Operations Report tracks water storage values daily through Excel spreadsheets
and associated graphs; and
WHEREAS, given the size and complexity of the Excel spreadsheets making up the Operations
Report, the Participants desire to describe the function of the Operations Report as it relates to
storage and document the relationship of the Operations Report to the Agreement;
NOW,THEREFORE,the Participants agree to amend the Agreement as follows: {
Section 20.5 is revised as follows:
Each week during every Operating Year, Tacoma shall transmit to each of the Participants a
report regarding the status of operations related to the Project. A sample weekly report is set
forth in Exhibit X and Exhibit AB provides documentation of the functions of the report. The
I
I
report will be transmitted to the Participants by means determined by the Project Committee
The Project Committee may from time to time revise the information to be included in the
weekly report by Tacoma.
Exhibit AB of the Agreement titled "Second Supply Project Water Storage Technical
Memorandum" dated September 10, 2010, as attached, is added as a new exhibit
Except as set forth herein, all other provisions of the original Agreement remain in full force and
effect.
IN WITNESS WHEREOF the Participants hereto have executed this Amendment No. 7 to the
Second Supply Project Agreement as of the day and year first written above.
City of Tacoma City of Kent
Department of Public Utilities
By: By.
Title: e: /)?/QV ol2—
Approved as to form & legality: Approved as to form le ity:
1
Covington Water District Lakehaven Utility District
By: By:
C
Title: G-e"p'4 l� (4c,auy' Title:
a
Approved as to form& lelga�lity: Approved as to f legality:
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Amendment No.7
Second Supply Project Agreement
Page 2 f
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SECOND SUPPLY PROJECT PARTNERSHIP AGREEMENT
EXHIBIT AB
SECOND SUPPLY PROJECT
WATER STORAGE TECHNICAL MEMORANDUM
September 10, 2010
PREFACE
The Second Supply Project(SSP)includes municipal water storage behind Howard Hanson Dam
(HHD)in the Green River Watershed for Tacoma Water (Tacoma) and the project participants
(or Partners) of Covington Water District(Covington), the City of Kent(Kent), and Lakehaven
Utility District(Lakehaven). The granting, availability, allocation, and management of storage
is described in the Second Supply Project Partnership Agreement(Partnership Agreement)
dated December 19, 2002, or as amended, and the Project Cooperation Agreement Between The
Department Of Army And The City of Tacoma For Modification Of The Howard Hanson Dam
For Ecosystem Restoration And Municipal &Industrial (W&I) Water Supply (Corps/Tacoma
Agreement) dated July 17, 2003
More specifically, the issue of project water storage at Howard Hanson Dam (HHD) is covered
in the Partnership Agreement in Sections 19 and 20 on pages 29 through 32. The definition of
the Howard Hanson Dam Additional Storage Project is found under article 1.1.12 on page 6 of
the Partnership Agreement and the definition of Project Modification for Municipal and
Industrial Water Supply is found in paragraph E on page 3 of the Corps/Tacoma Agreement
(Exhibit V in the Partnership Agreement).
The water storage project envisions two phases, Phase 1 and Phase 2, totaling 22,400 acre-feet.
Currently, only Phase 1 has been approved for implementation and includes up to 20,000 acre-
feet of water storage to elevation 1167. If Phase 2 is approved in the future, it will include an
additional 12,000 acre-feet of storage to elevation 1177, of which 2,400 acre-feet will be
allocated for municipal and industrial supply (See Exhibit W in the Partnership Agreement)
The availability of water storage to the SSP is further constrained by stream flow obligations in
the 1995 Tacoma-Muckleshoot Indian Tribe Agreement and Tacoma's Green River Habitat
Conservation Plan.
Tacoma has captured project water storage availability, allocation, restrictions, scheduling, use,
and management in the Tacoma and Second Supply Project Operations Report(Operations
Report). The Operations Report tracks these water storage values daily through Excel
spreadsheets and associated graphs. The report can be accessed online by going to:
http://www.ci.tacoma.wa us/water/ssp/re ig onal supply.htm
Definitions for several pertinent line items within the Operations Report are provided at the end
of this document to assist with understanding how the values are detennined. The calculations
associated with the report line item values take into account such data as:
• HHD inflow and outflow
• Stream flows at the Palmer and Auburn gages, and minimum flow requirements
• Tacoma's first diversion water right, and actual diversion
• Tacoma's second diversion water right, and actual diversion
• Flow passing through the R5,P5 and P 1 flow meters
Exhibit AB Water Storage Technical Memo Page 2 of 12
• Flow at Tacoma's SSP flow meter at SE 356`h St.
• Partner scheduled SSP water , and actual use
Note: additional detail on how these are measured or determined is provided in the "Definitions"
section of this document.
Exhibit AB Water Storage Tecluucal Memo Page 3 of 12
Second Supply Project Water Stored at Howard Hanson Dam
GENERAL
The HHD Reservoir Fill Period, including Second Supply Project(SSP) water, normally begins
in early February and ends by June 30. The SSP Stored Water Usage Period will last from when
the reservoir is declared full by the Corps of Engineers (usually sometime in June)until all SSP
stored water is used by SSP Partners, until the Corps declares a need to empty storage for either
dam safety reasons or flood control (typically occurs in November), or December 6", whichever
comes first.
Tacoma Water, Army Corps of Engineers, Muckleshoot Indian Tribe and several resource
agencies have regular meetings or conference calls during the reservoir fill and storage release
periods to share expectations and to coordinate the Green River resource. SSP Partners are also
invited to participate.
Reservoir Fill Period
As stated in the SSP Partnership Agreement, Tacoma and the Partners can use their allocated
SSP water during the reservoir fill period, or place all or a portion of the water into storage at
HHD. It is assumed all water will be placed into storage unless the Tacoma and the Partners
schedule the use of water on their weekly schedules (provided to Tacoma every Thursday)
indicating how much water they want diverted at Partner turnouts each day for the following
week. The Partners may change the scheduled weekly request after Thursdays provided the
Corps is willing to make a gate change at the dam. This request should be very infrequent.
Tacoma's full Second Diversion Water Right(SDWR) is 100 cubic feet per second (64.6 million
gallon per day (MGD)). The SDWR can only be diverted when Instream Flow Restrictions allow
it, but eater that has been diverted to storage can be used at any available rate (limited by pipe
capacity,plant capacity, etc). See the definition of SDWR, below. The Partnerslup is only
allowed to divert SDWR water at a rate up to the SDWR, including diversion to storage. If the
full amount of the SDWR is available everyday and if all Partners place all of the SDWR water
into storage, full storage of the entire 20,000 acre-feet could be reached in 101 days Therefore,
if storage begins on February 15th, full storage could be achieved as early as May 26 ').
Water available for storage is allocated to Tacoma and each Partner(Project Participants)
based on their share in the project Tacoma's share of the SDWR is 15/36 of 100cfs (26.93MGD
or 41 67cfs), and each of the Partners (Covington, Kent and Lakehaven) is allocated 7/36 of the
SDWR(12.57MGD or 19.44cfs). Project Participants are allowed to either use or store any
amount of water up to their maximum share without restriction. Each Partner could store water
at a different rate, depending on how much water they elect to use during the Reservoir Fill
Period. Each Partner can store and/or use water at a rate that doesn't exceed their share of the
SDWR(unless the Excess Project Capacity is considered, see below). Each Partner's rate of
storage, and total storage achieved, is documented daily in the Operations Report.
Exhibit AB Water Storage Technical Memo Page 4 of 12
Two factors may alter the end date of the Reservoir Fill Period:
• If the full amount of the SDWR is not available for a period of time, the rate at which water
is stored during that period is reduced from the maximum of 100cfs, and it will take longer to
fill the reservoir.
• If one or more of the Partners elect to use a portion of the SDWR(instead of placing all the
water into storage) for a period of time,the rate at which water is stored during that period is
reduced from the maximum of 100cfs, and it will take longer to fill the reservoir.
The daily allocation of the maximum of 100cfs,reduced by the Instream Flow Restrictions and
Partnership use, will continue until reservoir elevation 1167 is reached, 20,000AF has been
stored, or until the available inflows to the reservoir have dropped below the minimum values
and the Corp has determined that the Reservoir Fill Period has concluded.
If elevation 1167 is reached in the reservoir, or if 20,000AF of partnership water has been stored,
the reservoir is considered full and each partner will be considered to have reached their full
storage capacity. Tacoma will be considered to have 8333AF, and each other partner will be
considered to have 3889AF, regardless of water use during the Reservoir Fill Period.
If elevation It 67 and/or 20,000AF of partnership storage is not achieved (because Partners took
too much of the SDWR water during the fill period, or because hydrologic conditions were poor)
and the Corp has determined that the Reservoir Fill Period has concluded without the reservoir
being full, each partner will begin the Stored Water Usage Period with differing amount of stored
water based on their use of water during the Reservoir Fill Period. The Tacoma and Second
Supply Project Operations Report tracks the storage available to each Partner on a daily basis.
Each Partner will therefore; enter the Stored Water Usage Period with the storage they had
available on the day the Corp declared that the Reservoir Fill Period has concluded.
If a Project Participant achieves full storage (8333AF for Tacoma, 3889AF for other Partners),
and others have not yet achieved full storage,then the Project Participant that has achieved full
storage and can no longer make use of their share of the SDWR, and their share is reallocated as
Excess Project Capacity to other Project Participant(s). This could happen at any time during the
Reservoir Fill Period, but occurs most often after one Participant has achieved full storage, and
other(s)have not. The share of the Participant(s) with full storage is reallocated as Excess
Project Capacity share to other Participant(s)that have not yet achieved full storage. Excess
Project Capacity is reallocated to all Participants based on project share.
Once a Participants' storage account is full, any of that Participants' portion of the daily SDWR
water not delivered through the pipeline will be used to continue filling the project. This water
will be proportioned among the remaining Participants' allocated storage capacities.
Exhibit AB Water Storage Technical Memo Page 5 of 12
For example:
Storage account for a Participant=previous day's storage+ (Participant SDWR share on
current day minus water delivered to Partner on current day) +proportion of other
Participant's stored SDWR.
Assuming that Kent fills their storage first and the full SDWR is available,Kent's unused
portion that could be used to continue filling other Participant*s storage would be 12.6
MGD (7/36 of 64.6 MGD). This would be proportioned among the remaining
Participant's storage accounts according to their share of the SDWR and storage capacity.
Tacoma gets 2.1429 tunes the amount other partners get(15/7 =2.1429). So, Covington
and Lakehaven shares are "X" when Tacoma's share is 2 1429 X. Then X+X+
2.1429X= 12.6, with X=3.OMGD and 2.1429X=6.5MGD. So, Tacoma's fill rate
would be 26.9MGD plus their Share of Kent's Excess Project Capacity of 6.5MGD, for a
total new fill rate of 33.4MGD. Covington and Lakehaven would fill at a rate of
12.6MGD plus 3.OMGD, for new fill rates of 15.6MGD each.
Assuming that Covington fills their storage account next, then their unused 12.6MGD
plus Kent's unused 12.6 MGD would be proportioned between Lakehaven and Tacoma.
Then X+2.1429X = 25.2 MGD. Then X= 8.OMGD and 2.1429X= 17.2MGD. So,
Tacoma's fill rate would be 26 9MGD plus their Share of Kent's and Covington's Excess
Project Capacity of 17.2MGD for a total new fill rate of 44.1MGD. Lakehaven's storage
would fill at a rate of 12.6MGD plus 8 OMGD form Kent and Covington for new fill rates
of 20.6MGD.
Stored Water Usage Period
As stated above,the Stored Water Usage Period will last from when the reservoir is declared full
by the Corps of Engineers (usually sometime in early June)until all SSP stored water is used by
SSP Partners,until the Corps declares a need to empty storage for flood control (typically occurs
in November), or December 6'J1, whichever comes first.
As stated in the SSP Partnership Agreement, Tacoma and the Partners can use their portion of
the stored water at any available rate (limited by pipe capacity, plant capacity, etc). The SDWR
maximum diversion rate does not apply to storage drawdown as the SDWR water is considered
to have been diverted from the natural system at the time the water was placed into storage.
The Partners are required to fill out a schedule for the coming week that describes how much
water they may wish to take for each day of the coming week. Participants may take water at
any rate they wish. The schedule should be filled out and delivered to Tacoma every Thursday.
If conditions change through the week, and if a change to the amount of scheduled water is
needed, the Partner must inform Tacoma of the need Tacoma will request that the Corp make a
gate change to accommodate. The Corp may, or may not, be able to make a gate change,
depending on their availability.
During this time period, if SDWR water is available via run-of-river(which is usually not the
case at this time of year); the available SDWR water is divided among Participants based on
Exhibit AB Water Storage Technical Memo Page 6 of 12
Project Share. Any water requested in excess of what is available run-of-river will be provided
out of storage.
Stored water volume used by the Participants on a daily basis is calculated as the greater of: the
amount of water requested in their weekly schedule (or adjusted schedule, if the Corp was able to
accommodate the change), or the adjusted amount of water taken through their meters (see
Adjusted Meter Totals, below).
The volume of water available to each Participant is tracked on a daily basis in the Operations
Report The amount of water taken by a Participant on a given day is subtracted from the
previous day's total volume to determine the amount of stored water remaining available to a
given Participant.
Each Participant will approach the end of the Stored Water Usage Period at a different time
based on the amount of water they started with, and the rate at which they used the stored water.
As a Participant approaches the end of their allotted amount of stored water, they may request
additional water from other Participants. The other Participants must review the available
information and decide whether they have sufficient stored water to meet their own needs and
allocate water to the requestor, or not.
If no other Participants are willing or able to allocate water to the Participant(s)requesting
Excess Project Capacity, then the requestor must cease taking Project Water when their account
reaches zero. If other Participant(s) are able to allocate water to a requesting Participant(s),the
specific volume of Project Water will be debited from the assisting Participants' account(s) and
credited to the requestors' account(s).
In any case, as the Storage Usage Period moves into the fall, the Corp could release all stored
water almost without warning, this would effectively drain each Participant's storage volume at a
rate consistent with their Project Share.
Calculation:
Storage account for a Participant=previous day's storage—The greater of (Water
delivered to Partner on current day—Partner Share of SDWR Available Run-of-River—
or—Scheduled Amount of Water).
Exhibit AB Water Storage Technical Memo Page 7 of 12
KEY DEFINITIONS
The following definitions are key or crucial to determining how much water storage or run-of-
the-river water is available to the SSP Partners. An understanding of the definitions is vital for
someone to follow the calculations in the Tacoma and Second Supply Project Operations Report
Adjusted Meter Totals: The revised SSP Partner daily meter totals after proportionally adjusting
the actual Partner meter totals to match the total flow at the Project Master Meter located at
the Green River Headworks. See Exhibit T of the Partnership Agreement to see how the
adjustments are made.
First Diversion Water Right(FDWR): Tacoma's water right claim recognized by the State for
Tacoma's first diversion of the Green River that became operational in 1913. The claim is
for 113 cubic feet per second (cfs) or 73 million gallons per day (MGD). The quantity of
water available for municipal diversion under the claim is limited to the natural inflow at the
point of diversion, up to a maximum of 113 cfs. This quantity is calculated as the natural
inflow to Hanson Reservoir(as calculated by the Corp, see below)plus 2%, which allows for
side stream inflow, such as Bear Creek, into the Green River between Hanson Dam and
Tacoma's river diversion. Water under this water right claim is for Tacoma only, however, it
can be shared with other SSP Partners through wholesale agreement.
Flow at Palmer: The Green River stream flow measured at USGS Palmer gage 12106700
adjacent to Tacoma's Water Treatment Facilities near the Town of Palmer. Minimum stream
flows must be met at this gage for SSP water to be available for diversion as required by the
State and the Tacoma-Muckleshoot Indian Tribe Agreement.
Flow at Auburn: The Green River stream flow measured at USGS Auburn gage 12113000
within the City of Auburn. Minimum stream flows must be met at this gage for SSP water to
be available for diversion as required by the State and the Tacoma-Muckleshoot Indian Tribe
Agreement.
Flows-Palmer and Auburn Minimums: The minimum flows at the respective gages at
different times of the year as required by the Tacoma-Muckleshoot Indian Tribe Agreement
and the Habitat Conservation Plan(HCP). The minimum of 250 cfs at the Auburn gage or
Hanson Dam inflow will normally control the availability of SSP Run of River water in
summer and early fall while the Palmer gage may control at other times.
Howard Hanson Dam Inflow: The flow of surface and groundwater water into the reservoir
behind Howard Hanson Dam. The flow in cubic feet per second (cfs) is determined and
posted hourly by the Corps by observing the change in reservoir level in the last hour (acre-
feet), converting the change to efs (plus or minus) and adding the current dam outflow in cfs.
The reservoir level is measured by a pressure transducer in the water tower stilling basin.
Inflow to HHD =Change in reservoir level (can be+or-) +Outflow from HHD
Exhibit AB Water Storage Technical Memo Page 8 of 12
Howard Hanson Dam Outflow: The outflow of water from Howard Hanson Dam is measured
at Green River USGS gage 12105900 immediately downstream of the dam.
Partner or Project Share: As provided in the Partnership Agreement, each SSP Partner's share
of available SSP water is as follows: Tacoma-15/36 and for Covington Water District, Kent
and Lakehaven Utility District—7/36 each.
Pipeline No. I Flow: The flow of water in Tacoma's Pipeline No. 1 as measured at a meter
located about ''/4 mile downstream of Tacoma's Green River Water Treatment Facilities.
Pipeline No. 1 extends from the Treatment Facilities to McMillin Reservoir near Puyallup.
Run-of-River (ROR) Water: Water diverted directly from the stream into the transmission
pipeline SSP Partners have the option of taking their share of SSP water directly into the
pipeline (ROR water) or placing all or a portion of it into storage behind Hanson Dam during
the reservoir fill period. At times, ROR water and stored water may be available at the same
time to SSP Partners during the reservoir storage period.
Second Diversion Water Right(SDWR): Tacoma's water right permit granted by the State in
1986 for Tacoma's second diversion of the Green River that became operational in 2005 (See
Exhibit L in the Partnership Agreement). The permit is for up to 100 cubic feet per second
(cfs) or 64.6 million gallons per day (MGD). The quantity of water available for diversion
under the permit is limited to less than 100 cfs when stream flow drops below those stated in
the permit Water that is available under the SDWR may be used as run-of-river, or may be
added to HHD storage (considered as a diversion for water right purposes) The Tacoma-
Muckleshoot Indian Tribe Agreement of August, 1995 further restricts diversion of project
water under the permit by requiring minimum stream flows at the Auburn and Palmer stream
gages. Water under this water right permit is shared by all SSP Partners according to their
project share.
Scheduled Water. The project water requested by each SSP Partner in the weekly schedule
provided to Tacoma on Thursdays as provided in the Partnership Agreement within Section
20.3.
Second Supply Pipeline (Pipeline No. S) Flow: The flow of water in Tacoma's Second Supply
Pipeline as measured at a meter located about '/4 mile downstream of Tacoma's Green River
Water Treatment Facilities. The Second Supply Pipeline extends from the Green River
Water Treatment Facilities to Tacoma's Pipeline No. 4 in Tacoma.
Storage- Water for Municipal Use: Water that is available under the SD WR but that is not
used Run-of-River is defined as Stored Water for Municipal Use.
Storage- Conservation Pool. Water storage captured at Hanson Dam from late winter and
spring runoff and used to augment low Green River flows in summer and early fall. The
original design and operation of the Hanson Dam provided for 24,200 acre feet of water
storage to augment low flows. The conservation storage pool fills to elevation 1147. There
is no Municipal Component to this water.
Exhibit AB Water Storage Technical Memo Page 9 of 12
Storage-Section 1135: The project operation was subsequently modified in the 1990s to
provide an additional 5,000 ac-ft of stored water for fisheries benefits. 2500 ac-ft may be
used at Resource Agency discretion The remaining 2500 ac-ft may be used by Tacoma to
guarantee Auburn flows remain at or above 250 cfs. If Tacoma determines that flow
augmentation for supporting Auburn flows is not necessary in a given year, the 2500 ac-ft
reverts back to use by the Resource Agencies.
356°a Street Meter Total: The adjusted meter total for Tacoma's in-line meter at SW 356d' Street
in Federal Way. This is the last downstream meter on the Second Supply Pipeline and it
records all water going to Tacoma through the pipeline.
Exhibit AB Water Storage Technical Memo Page 10 of 12
KEY CALCULATIONS
As noted above,the Key Definitions Section contains word definitions of how each daily line
item in the Tacoma and Second Supply Project Operations Report is calculated. Clicking on a
value in the electronic report spreadsheet shows the mathematical definition of each line item
which is not always easy to follow. Therefore, the word definitions are helpful. The following
word definitions are the more key or vital definitions.
Available first Diversion Water:
The smaller of:
• 73 MGD (Maximum First Diversion Water Right Claim)
• Pipeline No. 1 Flow plus Second Supply Pipeline Flow plus the difference
between Auburn Gage Flow and the Auburn Minimum Flow of 250 cfs
• Hanson Dam Inflow plus 2% (2%for side stream flow between Hanson Dam&
Tacoma's Diversion)
Available Second Diversion:
The smaller o£
• 64.6 MGD (Maximum Second Diversion Water Right)
• (Line 20) Hanson Dam Inflow minus 113 cfs (I"Diversion maximum) minus
minimum allowable at the Palmer gage
• (Line 21) The difference between Auburn Gage Flow and the Auburn Minimum
Flow plus Second Supply Pipeline flow minus First Diversion Flow in the Second
Supply Pipeline.
• (Line 22) The difference between Palmer Gage Flow and the Palmer Minimum
Flow plus Second Supply Pipeline flow minus First Diversion Flow in the Second
Supply Pipeline.
First Diversion Taken by Tacoma:
The smaller of
• 73 MGD (Maximum First Diversion Water Right Claim)
• Pipeline No. 1 Flow plus Second Supply Pipeline Flow at 356fl' Street Meter
NOTE: Calculation will change when Cascade Water Alliance, Black Diamond or others
come online
Second Diversion Taken as Run-of-River:
The smaller of:
• Total Adjusted SSP Partner's Meters plus Pipeline No. 1 Meter plus 356"' Street
Meter minus 73 MGD (Maximum First Diversion Right)
• Second Diversion Allowable
Total Water from Hanson Dam Storage:
• Sum of Daily Partner Storage Draw-downs
Exhibit AB Water Storage Technical Memo Pagel 1 of U
Water from Hanson Dam Storage- Tacoma:
The larger of:
• Adjusted 356te Street Meter plus Pipeline No. 1 Meter minus Tacoma's share of
Second Diversion Allowable minus First Diversion Allowable
• Scheduled Water
Water from Hanson Dam Storage—SSP Partner:
The larger of
• Adjusted Partner Meter Total minus Partner's share of Second Diversion
Allowable
• Scheduled Water
Total Hanson Dam Storage—SSP Participant:
If between the Storage Begin Date and the Storage Achieved Date then:
• SSP Partners share of Second Diversion Allowable minus Partners adjusted meter
total
Exhibit AB Water Storage Technical Memo Page 12 of 12