The Tigard Water Service Area (TWSA) includes the cities of Durham, King City, two-thirds of Tigard and unincorporated areas to the south and west of Tigard. The City of Tigard is the water provider for the TWSA.
Currently Tigard purchases nearly 90 percent of its water from the Portland Water Bureau. The TWSA’s peak water demand can reach 13 million gallons a day, but as the population continues to increase, this number is expected to reach 20 million gallons a day by the year 2040. To meet the growing demand for water, Tigard needs to develop additional water sources.
In August 2008 the City of Tigard entered into a water partnership agreement with the City of Lake Oswego. Under the agreement, Tigard and Lake Oswego will jointly expand Lake Oswego’s water treatment facility and make other infrastructure improvements. These improvements, scheduled to be online in 2016, will allow Tigard and Lake Oswego to produce up to 38 million gallons of water per day. Of this amount, Tigard will receive between 14 and 20 million gallons per day. Depending upon future water demand, this source, along with Tigard's groundwater and aquifer storage and recovery wells, is expected to produce enough water to meet the needs of Tigard water customers to approximately 2035.
Sometime between 2035 and 2040, the TWSA will probably require an additional water source or sources. As a result the City of Tigard continues to investigate water source options, including the Willamette River Treatment & Transmission Improvement Project. In order for Tigard to use the Willamette River as a water source, transmission lines would need to be installed from the Wilsonville treatment plant to the City. Additionally use of this source would require the approval of Tigard voters.
City of Tigard’s web site at www.tigard-or.gov/water
City of Tigard's 2011 Annual Water Report (from 2010 data)
City of Tigard's 2010 Annual Water Report (from 2009 data)
City of Tigard's 2009 Annual Water Report (from 2008 data)