Our Region's Water

People cannot live without water, but we often take it for granted. Are you curious about where your water comes from? The answer is: It depends. 

Map of Water Supplies Portland, Oregon Metro Region

Residents living within the tri-county Portland-metropolitan area get their water from a variety of locations, including watersheds as far west as the Trask River (Coast Range), as far south as the Willamette River (in Wilsonville), and as far east as the Bull Run watershed (in the foothills of Mount Hood). Municipal drinking water supplies come from surface water sources (rivers and lakes), or groundwater (wells), or a mix of the two. 


While some people living in rural areas have their own wells, in urban areas there are public water providers that plan and manage a complex network of facilities that move water from a variety of sources to your home or business. This water supply infrastructure is made up of water treatment plants, pump stations, reservoirs, in-town storage tanks, and thousands of miles of pipes. The various water systems are individually managed by cities, water districts, and public utility districts. The people employed by these agencies work hard to ensure that the public’s water needs are met 24 hours a day, 365 days a year. 

Helping regional water providers manage their water supplies efficiently and safely are primary goals of a group called the Regional Water Providers Consortium, a group of more than 20 members that include water providers and Metro. The Consortium was formed in 1997 after a multi-year effort that resulted in the creation of a regional water supply plan. The group’s responsibilities have grown from planning for the region’s water needs to implementing conservation and emergency preparedness programs. 

Water supplies

Some areas receive all of their water from one source; other areas use a number of sources. You can always check your water bill to find out the name of your water provider, but the following provides general information about water sources by county.

Multnomah County

Water providers include the cities of Portland, Gresham, Fairview*, Troutdale*, and Wood Village*Rockwood Water People's Utility District (PUD); and several other smaller entities.

Water primarily comes from these sources of supply:

  • Bull Run River & Columbia South Shore Well Field - The City of Portland water system, which is made up of the Bull Run River and Reservoirs (located 26 miles east of Downtown Portland), supplemented during emergencies and the summer peak season by the Columbia South Shore Well Field, located between Blue Lake Park and the Portland Airport. 
  • Groundwater - Other sources of supply include groundwater developed by other entities, either as their sole source of supply or to augment water purchased from the Portland supply system. 

Washington County

Water providers include the cities of Tualatin, Tigard, Hillsboro, Forest Grove, Cornelius*, Beaverton, and Sherwood; the Raleigh, West Slope, and Tualatin Valley Water Districts; and several other smaller entities.

Water primarily comes from these sources of supply:

  • Joint Water Commission Water Treatment Plant - Some of the water providers use water from the Joint Water Commission Water Treatment Plant which gets water from Barney Reservoir in the Coast Range on the Trask River system, Hagg Lake on the Tualatin River system, and some water from the Tualatin River. 
  • Wholesale Contracts - In addition, some of these same providers have wholesale contracts to obtain water from the Portland Water Bureau supply system to serve as their primary source or to supplement their other source of supply. 
  • Groundwater - In some jurisdictions groundwater is also used.
  • Aquifer Storage and Recovery (ASR) - ASR is also used to help meet peak demand by taking surface water sources and injecting into the ground in winter (when supplies are more abundant) and pumped out for use in the summer months to augment other supplies.  

Clackamas County

Water providers include the cities of Sandy, Wilsonville, Gladstone, Milwaukie, Lake Oswego, West Linn, and Oregon City; Sunrise Water Authority; Boring, Lake Grove*, and Oak Lodge Water Districts; Clackamas River Water; and several other smaller entities.

Water primarily comes from these sources of supply:

  • Clackamas River - There are four individual “intakes” (sites along the river from where water is drawn) located in the lower three miles of the river before it flows into the Willamette River. There are four individual water treatment plants.
  • Willamette River – The Willamette River at Wilsonville is the site of a large water intake facility connected to a smaller water treatment plant which is the major source of supply in the City of Wilsonville.
  • Groundwater - In some jurisdictions groundwater is also used.
  • Surface Water Sources and ASR - In addition, the City of Sandy has two small surface water sources. ASR is also being explored or is being developed as a supplemental source of supply. 

A case for conservation

We are fortunate to have plentiful water supplies capable of meeting our current need for clean, safe drinking water. However, the amount of water available from each water source may vary from month to month, and the amount of water used by households in the summer months can be two to three times more than what is used in the winter months. It is also important to keep sufficient water in the rivers and streams to meet the needs of fish and aquatic life, as well as for other users.

What can you do? 

Be smart with the water you use so that there is plenty to go around. Get more information about how you can conserve water indoors and outdoors.

Download the entire water supply article and full-page map.

*Note: Fairview, Troutdale, Wood Village, Cornelius, and Lake Grove are not members of the Regional Water Providers Consortium. If you receive your water from these providers, contact them directly for more information.