Stormwater Facility Maintenance

Responsibility for Maintaining Catch Basins on Private Property

The City cleans and maintains catch basins in the public right of way. Any catch basins that are located on private property are to be maintained, and repaired by the property owner. If you have a catch basin in your backyard your homeowners association would be responsible for maintaining that catch basin.

The basic guidelines for maintaining catch basins can be found in the current city adopted Stormwater Management Manual for Western Washington pages 1178-1179. Maintenance Standard cleaning is to have them cleaned when the sediment exceeds 60 percent of the sump depth as measured from the bottom of basin to invert of the lowest pipe. On commercial property the City recommends cleaning catch basins once a year due to the fact that there is more traffic and possibility of pollutants in the solids in the catch basin. If you have questions regarding if your stormwater system needs cleaning, contact the Public Works Department at 425-921-5752.

Responsibility for Maintaining Stormwater Facilities

Stormwater facilities serving residential neighborhoods are generally owned and maintained by the homeowners in that subdivision. When plats are developed there are provisions written on the recorded plat map that will state who owns and is responsible for maintaining the detention facility.

The City of Mill Creek Municipal Code Section (15.14.110) Maintenance, repair and operation of the stormwater system, notes that if a private stormwater facility serves multiple lots and has not been specified on a subdivision plat, shot plat or other legal document, maintenance, operation and repair responsibilities shall rest on the homeowners association. In the cases within that subdivision. Stormwater facilities are typically located in tracts that are owned by the homeowners in the subdivision it is located in.

Stormwater facilities serving commercial property are owned and maintained by the owner of the property that the facility is located. The requirements are the same for maintaining stormwater facilities.

The City currently maintains approximately 38 public stormwater facilities (i.e. ponds, vaults, storm media-filter units, etc.), through a combination of annual inspections and, when needed, cleaning, replacing filters, etc. The City also maintains approximately 5,000 public catch basins, through a combination of inspection every two years and, when needed, cleaning and repair.

Your homeowners association president may receive a letter with items that need to be addressed after stormwater facilities are inspected. The letter will give you a timeline of when the items need to be fixed. If at any point there are questions or you need more time to complete the items listed on the letter feel free to call 425-921-5752.