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What is the Neighborhood Drainage Assistance Program?

The Water and Land Resources Division's Neighborhood Drainage Assistance Program (NDAP) addresses flooding, erosion and sedimentation problems affecting private property in unincorporated King County. The NDAP can design and fund capital improvement projects and repair existing drainage systems. Technical assistance is also available for questions about construction, permits, and storm drainage.

What types of problems receive assistance?

The NDAP targets problems beyond the control of private home and business owners. For example, construction, clearing, or filling in the upstream drainage basin may have changed the amount of water flowing to a drainage system. Some drainage systems might not function because the responsible party is not taking care of them. Other problems are caused by drainage code violations like flow diversions or blockages.

What kind of services does NDAP offer?

  • Construction projects
  • System repair and one-time maintenance
  • Technical assistance

What kind of problems won't the NDAP address?

  • Drainage problems involving one neighbor's runoff, unless the neighbor is very clearly violating a regulation
  • Very expensive problems requiring a major Capital Improvement Project
  • Problems caused in part by the affected property owner
  • Problems caused primarily by groundwater
  • Minor problems where little damage occurs, or damage from very large, infrequent storms may not qualify for funding. However, technical assistance may be available for these problems

How can the NDAP help you?

  • Call us at 206-477-4811 to discuss your concerns with Water and Land Resources (WLR) drainage investigators. We can schedule a site visit to determine if the problem qualifies for Neighborhood Drainage Assistance.

How are problems prioritized?

Because of the large number of eligible neighborhood drainage problems and a limited budget, Water and Land Resources (WLR) is not able to fund a solution for every problem investigated. The objective of the program is to correct as many of the most urgent of these problems as possible.

A WLR engineer will identify a possible solution for most problems after assessing their severity and frequency. Solutions are then ranked for funding based on their cost and the severity of the problem. Each project is then assigned to one of three WLR solution groups, and participants are notified.

The types of projects include constructing capital improvements, maintaining existing drainage systems, and enforcing of drainage code requirements.

What if no funds are available for your project?

If funds are not available for your project, WLR can still assist you with information and technical assistance. This may include construction suggestions; lists of engineers or contractors; permit requirement information; and sketches and details of common drainage facilities.

Call 206-477-4811 and ask for NDAP Technical Assistance.

How can you help us help you?

Keep a log of drainage problems. Take pictures or videos and make notes about what you have seen and heard during a problem, what you have done to try and fix it, and who you have talked to about it. 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 the height of flooding on your buildings, fences, or trees to help drainage investigators later. Consider attaching a yardstick to the side of your impacted house, fence, or other structure to record water levels during storms or floods.

Who can I contact if I have questions about this program?

Contact the Stormwater Services Section.

More information

King County's Drainage and Water Quality Complaint Inquiry Program

King County's on-line drainage complaint inquiry form for property owners in unincorporated King County.

For questions about the stormwater website, please contact Lou Beck in King County's Stormwater Services Section.