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The District 18 Watermaster’s Office is a field office of the Oregon Water Resources Department (OWRD) in cooperation with Washington County.

Appointments required at Walnut Street Center.

We are responsible for water supply management in the Tualatin, Lake Oswego and Lower Willamette Drainage Basins. We are a contact for local landowners, elected officials and watershed councils. Our responsibilities include:

  • Collecting streamflow measurements and groundwater level data
  • Maintaining gaging stations
  • Well inspections
  • Routine dam safety inspections
  • Stream recovery efforts
  • Providing information about water rights and Oregon Water Law
  • Mediating disputes between water users
  • Regulating water use during shortages
Look up Water Rights
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Visit the Oregon Water Resources Department to find information and apply for new water rights.

Water rights

Near Real Time Hydrographics Data
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Find current water flow data from gaging stations statewide.

Hydrographic data

Search for Well Report
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Learn about well depths, yield, and other information about wells on specific properties.

Well reports

Dam Safety
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Learn about the Dam Safety Program and see which dams we inspect.

​​​​Program information



1400 SW Walnut Street
Suite 240
Hillsboro, Oregon 97123

Hours and directions

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