Ground Water Management

We maintain wells where we measure water levels four times a year. Find water level data. The State Water Well Database tracks depths, yield and other data about wells on specific properties.

There are ground water restrictions in some areas with limited resources. See map. Heavy pumping has strained resources in regional ground water sources isolated in volcanic rock. The Water Resources Commission established Ground Water Limited Areas (GLWA) with special restrictions to help stabilize ground water levels.

There are three GLWA’s and one Critical Ground Water Area (CGWA) in Water District 18 boundaries. Contact us for information about tax lots within these areas:

Chehalem Mountain GWLA

Groundwater in this GWLA is allowed for exempt uses, irrigation and rural fire protection systems only.

Exempt uses include:

1. Stock watering
2. Lawn or non-commercial garden watering of not more than a half-acre
3. Single or group domestic purposes of no more than 15,000 gallons per day
4. Single industrial or commercial purposes not exceeding 5,000 gallons per day
5. Down-hole heat exchange uses

Exempt uses may not include irrigation or landscape maintenance of more than a half-acre.

Permits may be issued for up to five years for fire protection and drip or equally efficient irrigation. The Director must decide that the proposed use does not pose a threat to ground water resources or existing water right permit holders. The amount of water used for irrigation is limited to one acre-foot per acre per year.

Within two years of a permit being issued, the applicant must prepare a plan with steps to receiving an alternate long-term water supply for the Water Resources Commission.

Permits may be extended for an additional five years if the Director decides the ground water can support extended use. Applications and extensions may be denied if the aquifer is adversely impacted as defined in OAR 690-08.

Cooper-Bull Mountain CGWA

Ground water from the basalt aquifer within the CGWA is restricted to single family domestic and stock water purposes on tracts bigger than 10 acres.

Ground water for stock must be piped into tanks or troughs equipped with control works and operated to prevent the overflow and waste. If located within the area domestic use may include irrigation of up to a fourth-acre of non-commercial lawn and garden. If water in the well declines 20 feet or more from the original static water level, then the uses will be restricted to domestic and stock water use only. Ground water appropriated for domestic purposes is limited to that which can be beneficially. It cannot exceed one acre-foot (325,850 gallons) per year.

Parrett Mountain GWLA

Exempt uses include:

1. Stock watering
2. Lawn or non-commercial garden watering of not more than a half-acre
3. Single or group domestic purposes of no more than 15,000 gallons per day
4. Single industrial or commercial purposes not exceeding 5,000 gallons per day
5. Down-hole heat exchange uses

Exempt uses may not include irrigation or landscape maintenance of more than a half-acre.

Sherwood, Dammasch-Wilsonville GWLA

Exempt uses include:

1. Stock watering
2. Lawn or non-commercial garden watering of not more than a half-acre
3. Single or group domestic purposes of no more than 15,000 gallons per day
4. Single industrial or commercial purposes not exceeding 5,000 gallons per day
5. Down-hole heat exchange uses

Exempt uses may not include irrigation or landscape maintenance of more than a half-acre.