Drinking Water Supply

Beaverton's Drinking Water Sources

The primary source of filtered drinking water in Beaverton’s service area is the Joint Water Commission (JWC) Water Treatment Plant located south of Forest Grove. The water treatment plant filters surface water pumped from the nearby upper Tualatin River. The water treatment plant can produce up to 75 million gallons a day (mgd) of finished drinking water. The City owns a 25 percent share in the water treatment plant, allowing the City up to 18.75 mgd of treated water.

The City is a member of the JWC, which is an intergovernmental water supply group whose owner-members include the Cities of Beaverton, Hillsboro, Forest Grove, and Tigard, and the Tualatin Valley Water District. The JWC was established to store, manage, treat, and convey drinking water for the owner- member agencies and supplies water to as many as 400,000 people.

During the summer, when drinking water demand is high and Tualatin River streamflow is low, water is released from Hagg Lake (Scoggins Reservoir) and Barney Reservoir (formed behind a dam on the Trask River in the Coast Range). The water spilled from the two dams is to compensate for the amount removed from the Tualatin River for Beaverton’s summer use. Water released from Barney Reservoir is diverted by pipes from the Trask River basin into the upper Tualatin River.

The City of Beaverton owns yearly water rights of up to 1.3 billion gallons (4,000 acre-feet) in Scoggins Reservoir and 1.4 billion gallons (4,300 acre-feet) in Barney Reservoir. Water originating from Scoggins Reservoir and Barney Reservoir is the source of most of the City’s raw water (before treatment) during the summer. Release of stored raw water from the two dams increases summertime streamflow in the Tualatin River, helping to sustain a healthy river ecosystem. Every winter and spring, the City uses its 16 mgd natural streamflow water right to meet daily water supply demands. Surface water from the Tualatin River is filtered in the JWC Water Treatment Plant before delivery to the City of Beaverton.

Finished drinking water from in the JWC Water Treatment Plant is pumped about one-half mile up to the Fern Hill Reservoirs, two 20-million-gallon MG, aboveground storage reservoirs situated at 520 feet elevation. To transport water from the water treatment plant to Beaverton, the City owns 14 mgd capacity in the JWC South Transmission Line. The City also owns emergency backup capacity in the parallel JWC North Transmission Line. From the two Fern Hill Reservoirs, water travels about 20 miles by gravity through large-diameter transmission lines to Beaverton, where the City’s two terminal water storage reservoirs are located in central Beaverton. The City’s two terminal water storage reservoirs hold a combined total of 20 MG.

Since 1999, the City has used aquifer storage and recovery ASR to temporarily limit the purchase of new water supply facilities. During the winter and spring, Beaverton injects treated drinking water from the JWC Water Treatment Plant into natural underground basalt formations (aquifers), displacing native groundwater. During the summer months, treated water is recovered from ASR wells to supplement JWC surface water to help meet peak season demands (up to 17 mgd).

Acting as a conservation measure, ASR conserves surface water from primary sources (rivers and dams) during environmentally stressful summer seasons. Beaverton has reduced its diversion of limited summer river streamflow and water stored behind dams by substituting stored water recovered from ASR wells (for more on ASR, see Storing Drinking Water Underground — ASR).

Your City Water System at a Glance

Drinking water is one of the most critical services that the City provides on a daily basis to the residents and businesses of Beaverton. In 2008, the City supplied drinking water to 69,000 residents, or about 80 percent of the total 86,205 residents who live within the City limits. The remaining 20 percent of our residents’ water is supplied by the Tualatin Valley Water District, West Slope Water District, and Raleigh Water District.
Following are facts about the City’s water system:

• The distribution system includes five local water storage reservoirs, with a combined total storage volume of 28.25 MG.
• The City owns additional reservoir storage of 10 MG near the JWC Water Treatment Plant.
• The distribution system (separate from the JWC supply system) consists of approximately 263 miles of pipe, ranging from 4 inches to 36 inches in diameter.
• In 2008, the City consumed an average of 7.46 mgd or a total of 2.72 billion gallons of water. On August 16, 2008, the City consumed 13.7 MG of drinking water, the highest demand day.
• The City has a 3- to 4-day supply of stored drinking water in its local reservoirs.
• The distribution system contains four pumping stations that lift water from the largest water service pressure zone on the valley floor to the nine other higher elevation water pressure zones within the City’s water service area.
• The City’s owned capacity in the JWC Water Treatment Plant is 18.75 mgd.
• The City has an additional water supply of 6 mgd available from ASR wells, commonly used only in the summer.
• In addition to the JWC and ASR wells, there is an emergency supply capacity of 8 mgd available from two adjoining public water providers (Tualatin Valley Water District and the City of Portland).

 

Water Source Project for the Future

Water resources agencies in Washington County are working to ensure clean, safe and reliable water supplies for the environment and needs of a growing community. They have formed a water supply partnership to finance and plan for future water supplies from the Tualatin River. The Tualatin Basin Water Supply Project partners include Clean Water Services; Tualatin Valley Water District (TVWD); and the cities of Hillsboro, Forest Grove, Beaverton, Tigard, and Tualatin in partnership with the U.S. Bureau of Reclamation (USBR). The USBR is the builder and owner of the Scoggins Dam/Hagg Lake.

In June 2001, the Beaverton City Council authorized signing of a funding agreement to participate in a Water Supply Feasibility Study of the Tualatin River basin, the first phase in the Tualatin Basin Water Supply Project. Completed in 2004, the study evaluated alternatives for reliable, safe, and sustainable water supply options to meet the long-term Tualatin River streamflow, agricultural irrigation, and municipal and industrial water needs in Washington County to the year 2050. The Tualatin Basin Water Supply Project is being led by Clean Water Services in partnership with other agencies listed above. Beaverton’s current level of participation in the Tualatin Basin Water Supply Project is 1,763 acre-feet (574 million gallons of storage) or 3.33 percent of the total nominal 52,900 acre-feet of new raw water storage that would be created in an expanded Scoggins Dam with a 40-foot dam raise. The Scoggins Reservoir expansion would nearly double the current volume of the reservoir totaling 60,640 acre-feet (usable volume 53,640 acre-feet).

From 2005 to date, an alternatives analysis examined the various supply options and two were presented in an Environmental Impact Statement. The first alternative is a 40-foot dam raise of Scoggins Dam (at Hagg Lake) with a large-diameter raw water pipeline pumpback from the Tualatin River to refill Hagg Lake each year. The second alternative is a multiple source option that includes a 25-foot raise of Scoggins Dam with a large-diameter raw water pipeline pumpback, and expansion of the Willamette River Water Treatment Plant located in Wilsonville.

The City currently owns a right to use up to 4,000 acre-feet in Hagg Lake and 4,300 acre-feet in Barney Reservoir for summertime water supply. During the summer, water in the two reservoirs is released into the Tualatin River as needed to meet the City’s potable water demand. The City of Beaverton acquired rights to its 4,000 acre-feet of water in Scoggins Reservoir (Hagg Lake), referred to as the Tualatin Project, under two separate contracts with the US Department of the Interior, Bureau of Reclamation.

Tualatin Basin Water Supply Project (TBWSP)

As communities in the Tualatin Basin continue to grow, more water is needed for municipal drinking water and industrial uses. In addition, more water is needed to augment flow in the Tualatin River and its tributaries for water quality.
In 2001, water resource agencies in the Tualatin Basin formed a partnership to study and decide how to best serve the water needs of the future. Beaverton has financially participated in the TBWSP feasibility work since signing an agreement in 2001 with the other project partners.

The TBWSP involves raising the height of Scoggins Dam (which forms Hagg Lake); construction of a large pipeline from the dam to the JWC Water Treatment Plant; a large pumping station located below the dam to pump water from the Tualatin River into the lake during the winter; and expansion of the JWC Water Treatment Plant south of Forest Grove. Scoggins Dam and Hagg Lake are owned by the U.S. Bureau of Reclamation (USBR), which built the facility in 1970. The TBWSP will add approximately 53,000 acre-feet of water to Scoggins Reservoir (Hagg Lake) per year (1 acre-foot is the amount of water it takes to fill an acre of area with 1 foot of water). The City of Beaverton is a partner and has a 3.8 percent interest in the project to eventually own an additional 2,000 acre-feet (0.65 billion gallons). The City currently has a contract with the USBR that gives the City a right to use up to 4,000 acre-feet each year (1.3 billion gallons).

The TBWSP is a collaborative effort. Besides providing additional supply for municipal water needs, the project will provide environmental benefits and a stable water supply for agricultural uses. Clean Water Services is the lead agency for the project, providing project management and public involvement. Project partners include:

• Clean Water Services
• Tualatin Valley Water District
• City of Hillsboro
• City of Forest Grove
• City of Beaverton
• Lake Oswego Corporation
• Tualatin Valley Irrigation District
• U.S. Bureau of Reclamation (USBR)
• Washington County

Draft Planning Report/Environmental Impact Statement (PR/EIS)
The tentative schedule for completion of the project’s Draft PR/EIS is fall/winter 2009. The Draft PR/EIS will be published by the USBR and distributed to interested parties. It also will be available for review on the City’s website and at various local libraries.
USBR Title Transfer
TBWSP partners are working with the USBR to transfer ownership of Scoggins Dam, Hagg Lake (and adjoining federal lands), and irrigation facilities from the USBR to the TBWSP partners. The title transfer also would include operation and maintenance responsibilities, legal liability and regulatory requirements to the TBWSP.
Title transfer offers several potential benefits to both local water resource managers and the federal government:

• Flexibility: Local ownership and control of facilities and water rights would reducedecision-making complexity and improve flexibility of water management.
• Efficiency: Local ownership would allow for the more efficient management of water resources in the Tualatin Basin as decisions are made on a local basis.
• Improved Integration: Local ownership would allow regional water mangers to better integrate operations of Scoggins Reservoir (Hagg Lake) and Barney Reservoir to meet water needs of the basin.
• Reduce Federal Obligations: Title transfer would allow the federal government to divest itself of responsibility for ongoing operations, maintenance, replacement, and liability.
• Time/Cost Savings: Local ownership could offer significant time and cost saving for future improvements.

For more information about the TBWSP go to:
http://www.tualatinbasinwatersupply.org/