About our water supply

Almost all water used in Clark County comes from underground aquifers which are tapped by a series of wells. In contrast, Portland gets most of its supply from above-ground sources, such as the Bull Run reservoir.

Most of Clark Public Utilities' wells are located in the Salmon Creek watershed. The average depth of our wells is 250 feet. Four aquifers are the source of water:
1) Recent Alluvial Aquifer
2) Troutdale Aquifer
3) Sand and Gravel Aquifer
4) Fractured basalt formations

Here is a cross-section of the hydro-geologic structures in Clark County. For more information, call 360-992-8023.

No fluoride or other chemicals, other than the required level of chlorination, are added to the water supply. The quality of the water is excellent -- and we test it regularly to make sure it stays that way.

The average annual use per customer is 115,000 gallons.

Clark Public Utilities has 34 wells which have a pumping capacity of 24.5 million gallons of water per day. Water is stored in 25 reservoirs with a combined storage capacity of 11.7 million gallons. We have about 700 miles of distribution lines. The utility also manages 20 independent water systems throughout the county.

Most of the utility's water wells are in the Salmon Creek watershed. The stream flow of Salmon Creek is regularly monitored. Follow this link to find stream flow information about Salmon Creek and other county waterways.

We're presently considering a dramatic change in the source of our future water supplies. We are examining the feasibility of developing a new well field southeast of Vancouver Lake. Called the "South Lake Well Field," it would take an estimated three to five years to fully develop. As envisioned, the project would include eight wells with a pumping capacity of about 36 million gallons a day.