2006 Tacoma Water Comprehensive Water
System Plan Update
Water’s planning activities center on the need to meet increasing
demands in an expanding service area, to address local, state and
federal government planning policies and regulations, to satisfy
Department of Health planning guidelines and to satisfactorily
address customer expectations. As a municipal water supplier, Tacoma
Water is required by the Washington State Department of Health to
update its water system plan every six years. The 2006 Tacoma Water
Comprehensive Water System Plan Update
assists Tacoma Water in making the best use of available resources
in order to provide quality water services and protect the health of
its customers. The Plan accomplishes the following objectives:
Provides Tacoma Water
with a guide to evaluate the impacts of future proposed development
and land use changes on the water system
Identifies existing and
potential water resources available to Tacoma Water.
Provides a review of
existing water quality data for Tacoma Water’s system and discusses
existing and forthcoming regulatory requirements as they apply to
the water system.
Conducts a water system
inventory, including a description of supply, storage and
distribution facilities operation.
Establishes water system
policies that will help Tacoma Water make decisions and manage the
water system, incorporating the requirements discussed in the water
resource, water quality, water supply and water distribution
sections of the Plan.
Documents Tacoma Water’s
Satellite System Management program.
Documents planning and
design criteria used by Tacoma Water.
Identifies existing and
potential future water system deficiencies by conducting storage and
transmission/distribution system analyses.
Develops a program of
capital improvements, including priorities for construction and
provides a financial evaluation to support the identified water
Documents Tacoma Water’s
commitment to implementing an effective conservation plan as an
element of the overall Tacoma Water resource mix.
Documents Tacoma Water’s
Green River Watershed Control Program.
Responds to new water
system planning requirements resulting from the 2003 Municipal Water
Law (HB 1338).
Water’s ten- year Business Plan Strategic Initiatives into the water
The Planning Process
The multi-year process of
updating the Tacoma Water Comprehensive Water System Plan included
agency, stakeholder and public outreach activities. The Department of
Health and Tacoma Public Utility Board have approved the 2006 Tacoma
Water Comprehensive Water System Plan Update. The 2006 Tacoma Water
Comprehensive Water System Plan Update consists of
(titled Green River Watershed Management Plan). Questions on the 2006
Tacoma Water Comprehensive Water System Plan can be directed to Susan
Clark at 253-502-8204 or
Green River Watershed Management Plan (Volume
II, August 2006 )
of the 2006 Comprehensive Water
System Plan Update (Green
River Watershed Management Plan)
serves as documentation of the
watershed control program implemented by Tacoma Water for the Green
River Watershed. Washington Administrative
Code 246-290-690 mandates that public water supply systems using
unfiltered surface water develop and implement a Department of
Health approved watershed control program to avoid degradation of
the physical, chemical, microbiological, and radiological quality of
the source of the supply. The
Green River Watershed Management Plan
characterizes the watershed hydrology, geography and critical areas;
details landowners and written agreements with landowners;
identifies watershed characteristics and activities that may have an
adverse effect on source water quality; summarizes monitoring and
control of watershed activities; and discusses potential future
improvements in watershed control.
As required by
the Washington State Department of Health, Tacoma Water has been
developing a water conservation plan to be included as an element of
Tacoma Water Comprehensive Water Plan
Since the 1980s,
Tacoma Water has been committed to implementing an effective
conservation program as an element of the overall water resources
plan. The focus has been on developing
long-term sustained conservation activities in a balanced program
including both supply management and demand management measures.
The conservation measures have been designed to increase
customer awareness of conservation issues, to provide incentives for
reduced consumption and to reduce water losses within the system.
The general goal
of Tacoma Water’s conservation program is to protect and preserve
present and future water resources and to maintain or reduce present
per capita water usage levels in all customer classes. Tacoma
Water’s specific conservation goal is to reduce per capita water use
by 10 percent over the ten year time period 2000 to 2010.
In 2006, Tacoma
Water undertook a conservation program assessment to evaluate the
existing water conservation program – which is based upon a 1997
conservation program assessment – and to recommend elements to
strengthen the program. The objectives of
the 2006 Conservation Program Assessment include:
To instill a long-term conservation ethic among customers
(retail, wholesale and in regional supply area).
To establish a 2000 base year on water use. This will enable
the utility to measure the effectiveness of the conservation
program in accordance with State guidelines.
To establish criteria to assess the effectiveness of the
conservation program including methods to establish savings,
effectiveness of public information programs and measurements of
economic benefits received.
To identify conservation program activities which, if
implemented by Tacoma Water, will result in water savings
necessary to meet Tacoma Water’s 10 percent reduction goal.
results of the conservation
program assessment were
used to develop the
Tacoma Water Conservation Plan.
Over the next four
years – through 2010 – Tacoma Water will select for implementation
the conservation program packages that are cost effective for
customers. The water conservation program
packages that may be implemented include:
Faucet Aerators & Low Flow Showerheads for Residential Customers
High-Efficiency Toilets for Residential Customers
Pre-Rinse Spray Valves for Commercial Customers
High-Efficiency Clotheswashers for Residential Customers
High-Efficiency Urinals for Commercial Customers
High-Efficiency Commercial Kitchen Equipment
Water Efficient Product and Service Promotion
Intergovernmental & Regional Cooperation
Tacoma Waters Service Area
and Water Use
provides water service to residences, businesses and industries located
in the cities of Tacoma, University Place and Ruston; in portions of the
cities of Puyallup and Federal Way; and, in portions of Pierce and
southern King county. Tacoma Water also
provides wholesale water supplies to 14 independent water systems
operating in Pierce and King counties and provides management services
to the Tacoma Narrows Airport located on the Gig Harbor Peninsula.
Tacoma Water is a participant in, and operator of, the Second
Supply Project: a new regional water
partnership between Tacoma Water, the Lakehaven Utility District, the
City of Kent and the Covington Water District.
To view a map of Tacoma
Water's service are click
As of year-end 2006,
Tacoma Water provides retail water service to approximately 94,000
connections or an estimated population of 302,392.
While single-family residential connections account for the
majority (89 percent) of Tacoma Water’s customer base, water use by the
single-family customer class accounts for 36 percent of total water
consumption. On the other hand, one industrial
connection (the Simpson Tacoma Kraft Mill) accounts for 27 percent of
total water consumption. The multi-family
customer class makes up 5 percent of Tacoma Water’s customer base and 12
percent of total consumption, with commercial connections accounting for
6 percent of the customer base and 15 percent of consumption.
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Supply Starts at the Green River Watershed
Green River begins in the Cascade Mountains near Stampede Pass and
serves as Tacoma Water’s primary water supply. For more than 80 years,
Tacoma Water has managed the Green River watershed. This forested land
serves as a collecting point for melting snow and seasonal rainfall.
The watershed covers 148,884 acres on the west flank of the
Cascade Mountains between Chinook and Snoqualmie passes. Tacoma Water
owns only 10 percent of the watershed, but has agreements with other
landowners to limit activities in order to keep the Green River water
supply pure and fresh.
Tacoma Water’s First Diversion water right
is for up to 73 million gallons of water each day (MGD). Tacoma Water
can substitute this Green River supply with water from seven wells
located along the North Fork of the Green River. The well field can
normally meet the same 73 MGD production as the Green River in the
winter and spring months. The North Fork wells are used only when the
water in the river is too turbid (or cloudy), usually in the fall and
winter, or in the event of other unusual or unacceptable water quality
in the Green River.
addition to Tacoma Water’s First Diversion water right, the Green River
is also the source of supply for a regional partnership formed by the
City of Kent, the Covington Water District, the Lakehaven Utility
District and Tacoma Water. The Second Supply Project, named after the
fact that this is the second supply coming from the Green River,
supplies up to 65 MGD to Tacoma Water and its Second Supply Project
Partners. The Partners participate in the Second Supply Project
under the terms of the Second Supply Agreement. Tacoma Water has a 15/36
Participant Share and the City of Kent, the Covington Water District and
the Lakehaven Utility District each have a 7/36 Participant Share.
Generally, a Participant Share represents a participant’s proportional
right to receive, and obligation to pay for, water delivered by the
Second Supply Project.
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Groundwater Helps Meet Growing Needs
In addition to surface
and groundwater sources from the Green River watershed, Tacoma Water
owns 24 wells located in and around the city.
These wells pump water from aquifers, which are underground layers of
water saturated sand and gravel. This water
comes from local rainfall, which has percolated deep into the soil.
Tacoma Water’s wells have a short-term combined pumping capacity
of about 60 million gallons per day.
Approximately 15 percent of total annual water requirements are met
through the use of the Tacoma Water groundwater sources.
Current plans call for the development of additional well
capacity, consistent with existing water rights, to meet projected
future water requirements.
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Storing Water to
Meet Peak Demands
Tacoma Water has built
a storage system consisting of the 210-million-gallon McMillin Reservoir
located near Puyallup, plus 16 other reservoirs, standpipes and tanks
that can store up to 78 million gallons of additional water.
This system, operated mostly by gravity, assures that water can
be supplied economically to customers throughout the Tacoma Water
service area. Planning is underway to convert
the currently uncovered McMillin Reservoir to a covered facility with
reduced capacity. Design work is to occur in
2008 with the first of three 30 to35-million-gallon tanks to be
constructed in 2009.
Alaska Street Reservoir
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The Future The Second Supply Project
To meet its own future
water supply requirements, as well as to increase regional supply,
Tacoma Water has been developing the Second Supply Project since 1968.
In 1970, a plan was developed for another transmission main, Pipeline
No. 5 (now also known as the Second Supply Project Pipeline) to convey
additional water supply to the City and to blend water from the North
Fork Well field with Green River water during
high turbidity events. Phase I of the project,
development of the well field, connecting pipe
and reservoirs was completed in 1975.
II, design and construction of the transmission main, was hindered by
politics and evolving environmental laws in the early 1980s.
The Second Diversion water right on the Green River was finally
awarded in 1986. In 1995, an agreement with
the Muckleshoot Indian Tribe (MIT) regarding the Green River was
reached. All major permits and permissions for
the construction of the Second Supply Project Pipeline were acquired by
1997. By 2001, a Partnership Agreement between
Tacoma Water, the City of Kent, the Lakehaven Utility District and the
Covington Water District was enacted which covers each participants’
rights and obligations regarding the use of the Second Supply Project.
Although the Second Supply Project was developed as a joint
venture known as the Regional Water Supply System (RWSS) and operation
and maintenance of the RWSS is jointly funded by the Partners, the
operation and maintenance of the RWSS is carried out entirely by Tacoma
Water, in a manner as described in the 2002 Second Supply Project
In total, the Second Supply Project
consists of the following components:
River water as allowed under Tacoma Water Green River Second
Diversion water right;
34-mile-long Second Supply Project Pipeline;
Improvements made at the Tacoma Water Headworks diversion dam and
Second Supply Project fisheries and environmental enhancements,
including a new fish trap-and-haul facility at the Headworks
right to store water as a result of the Howard Hanson Dam Additional
Storage Project; and
Treatment Facilities (disinfection, pH adjustment, fluoridation and
After many years of
preparation, major construction of the Second Supply Project began in
1999. In 2000, the Tacoma to Federal Way
portion of the Second Supply Project Pipeline was completed and
Lakehaven Utility District began receiving water from another portion of
the Tacoma Water system. In 2002, the upper
ten miles of the Second Supply Project Pipeline was completed and placed
in service, delivering water to the City of Kent and to the Covington
Water District. Changes to the Headworks
diversion facilities, including the addition of a new fish trap-and-haul
facility, were completed in 2006. The new Phase I water treatment
facilities (chlorination, fluoridation and pH adjustment) were finished
and placed in service in August 2005. Ozone
treatment and an integrated operations center are anticipated to be
completed by 2007. On October 20, 2005, Second
Supply Project water began flowing through the entire 34-mile-long
Second Supply Project Pipeline. On May 16,
2006 Tacoma Water made use of the Second Diversion water right to meet
demands for the first time.
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Howard Hanson Dam
Additional Storage Project
Howard Hanson Dam spans the Green River
approximately three miles upstream from Tacoma Water’s Headworks
diversion dam, where water from the Green River is diverted by Tacoma
Water. The Howard Hanson Dam was built in
1961. The U.S. Army Corps of Engineers (USACE)
operates the dam, controls water levels in the reservoir, and regulates
flow in the Green River for flood control in the winter and
flow-augmentation during low-flow periods (typically late summer through
fall). The primary authorized use of the
project is to provide flood control for the Green River Valley during
the winter. Secondary authorized uses include
augmentation of low summer flows downstream of the dam, irrigation, and
water supply. The dam impounds the Green
River, forming the Eagle Gorge Reservoir.
Water and the USACE are working in cooperation on the Howard Hanson
Additional Water Storage Project. This project
– a component of the Second Supply Project - will increase the amount of
water stored behind Howard Hanson Dam for use as municipal supply by
increasing the surface elevation from 1147 feet (above sea level) to
1167 feet. This will increase the stored
volume of water by approximately 75 percent. Concurrent with this
increased storage volume, a new downstream Fish Passage Facility is
being constructed to enhance survival and passage of out-migrating
juvenile fish. This facility will
predominantly take water off the top water elevations from the
reservoir, rather than the deep elevations, as is currently the design.
Storage plus downstream migration is expected to be in service by
2009, with some storage capability available in 2007.
Under the Howard Hanson Dam Additional
Storage Project, Tacoma and its Second Supply Project Partners will have
the ability to store up to 20,000 acre-feet (AF) of water behind Howard
Hanson Dam during the spring. Tacoma Water’s
share of the stored water is 15/36, or up to 8,333 AF, which equates to
30 MGD (million gallons per day) if used at a
uniform rate over a 90-day period.
If water is diverted to storage during the
spring, it will not be available for consumption during the spring.
Each year Tacoma Water, the Lakehaven Utility District, the City
of Kent and the Covington Water District will each need to decide if
they want to divert water to storage during the spring and meet spring
demands using other sources of water, or consume Second Supply Project
water during the spring and rely more heavily on other sources during
the summer. In either case, the Additional
Storage Project will provide flexibility in how sources are used and
will allow for the movement of less valuable spring-time water into the
summer where it is more valuable given increased summer demand.
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