Private Stormwater Maintenance Program

Private Stormwater Inspection

The City works with property owners to ensure routine inspection and maintenance of all private stormwater systems. Proper maintenance ensures the system continues to function as designed. It also helps keep our creeks and lakes clean, and helps prevent flooding and erosion.

Use this interactive map to find private stormwater systems on your property and information on how to maintain them.

Understanding Your Stormwater System

Typical stormwater systems have many parts to carry runoff from your property. These parts may include:

Roof drains and underground pipes
Catch basins and yard drains
Swales, culverts, and ditches
Oil/water separators
Buried retention, detention, and infiltration vaults and pond

Retention and detention facilities prevent flooding and reduce pollution by storing stormwater in ponds or underground vaults. These facilities slow the rate of runoff and also allow pollution to settle out before the water enters our creeks and lakes.

Stormwater System Inspection Process

Inspection of private stormwater systems occurs at least every other year:

The City notifies property owners by letter when it is time for their next inspection.
The City inspects the drainage system and works with the property owner to familiarize them with their system and how to maintain it.
Staff will notify the property owner if a system does not meet Kirkland’s maintenance standards. Upon notification, the property owner will be responsible for completing the necessary maintenance.
If maintenance is required, you and your contractor will need to fill out and submit a Certificate of Completion(PDF, 13KB) when the work is complete. Please include all maintenance done on your system since the date it was inspected by the City. If you hired a contractor to perform the maintenance, have them sign the form as well. Submit the completed form to the Storm & Surface Water Division, Kirkland Public Works Department.

Maintaining Your Stormwater System

Maintenance requirements for stormwater facilities are in Appendix A of the 2021 King County Surface Water Design Manual. Typical stormwater system maintenance requirements might include:

Cleaning contaminated sediment/liquids from ponds, pipes, catch basins, and manholes
Repairing/replacing control structures

Prevent materials stored outside from leaking, draining, spilling or dumping into the stormwater system. Keeping contaminants out of your system reduces disposal costs for materials cleaned from the system.

The City provides a list of local firms that provide drainage maintenance services: Drainage Maintenance Contractor List(PDF, 135KB).