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King County unincorporated area property owners could qualify for drainage assistance


The Neighborhood Drainage Assistance Program helps with flooding and drainage problems affecting private property in unincorporated King County.


With the rainy season underway, residents in unincorporated King County who see drainage problems in their neighborhoods can seek assistance in solving those problems through the County’s Neighborhood Drainage Assistance Program (NDAP).

The program helps find solutions for drainage problems that are beyond the control of home and business owners, and aren’t considered routine maintenance or a groundwater problem.

For example, changes in upstream land use, even when done in compliance with King County codes, can have individual and cumulative impacts on downstream drainage systems.

These problems are more apparent during the rainy season. Property owners should take these steps when they find a drainage problem:

• Document drainage problems with photos, videos and notes, including what you have done to fix these problems, and who you have talked to about them. Include the date and time of day with all notes, photos, and videos.
• Document the problem on the ground. Stake the edges of high water in your yard, and mark and record the height of flooding on your buildings, fences, or trees to help investigators later.
• Observe where and how water flows onto and through your property. Pay attention to flooded areas, to areas where the water moves swiftly, and to areas where water flows down steep slopes.

For help, call the Drainage and Water Quality Complaint line at 206-477-4811. An investigator may schedule a visit to get a first-hand look at your drainage issues. An engineer will assess the severity and frequency, and identify possible solutions for most problems. Solutions are ranked for potential funding based on cost and severity.

Because of the large number of eligible neighborhood drainage problems and a limited budget, not all issues can be funded. The NDAP tries to fund as many of the most-urgent problems as possible.

If funds are not available for your project, employees with the King County Water and Land Resources Division can offer information and advice, including:

• Suggestions about potential construction solutions;
• A list of engineering, contractor, and mediation services;
• Permit requirement information; and
• Sketches and details of common drainage facilities.

Your property could also remain on the NDAP potential project list for possible future funding.
Call 206-477-4811 to discuss drainage or water quality problems, or visit and follow the “report a problem” link or “neighborhood drainage assistance” link for more information.