Our stormwater regulations protect people, property and the environment from damage caused by stormwater runoff. Our stormwater codes also satisfy the City's obligation to comply with our Municipal Stormwater Discharge National Pollutant Discharge Elimination System (NPDES) Permit, issued by the Washington State Department of Ecology.
- Drainage control submittal and review requirements
- Erosion control requirements for your project during construction and grading activities
- Flow control and stormwater treatment requirements
- How we enforce the Stormwater Code
- On-Site Stormwater Management and why it's important
- Where the stormwater from your site needs to go
Managing stormwater runoff is an important responsibility of the City of Aberdeen and its citizens. Stormwater that does not infiltrate into the ground becomes surface runoff that collects pollutants and discharges them to our City’s waterways. The City has adopted the most current version of the Stormwater Management Manual for Western Washington (SWMMWW) as its stormwater design standards and guidance document. All projects shall adhere to the SWMMWW in the design and construction of stormwater improvements.
If your project includes adding new or replaced hard surfaces or plan to remove vegetation on your property, you may be required to obtain a Site Development Permit. Site Development projects require engineering review to assure compliance with Aberdeen Municipal Code - Chapter 13.70 (Storm and Surface Water Management).
All projects - regardless of size - are required to provide a Construction Stormwater Pollution and Prevention Plan (CSWPPP) and manage construction stormwater runoff from project sites, demolition, clearing, and grading projects.
The Project Thresholds are defined below, including the required permit submittals.
If the project results in less than 2,000 square feet of new plus replaced hard surface area, and, involves less than 7,000 square feet of land disturbing activity, then the required submittal is the Standard City CSWPPP Form.
(No further stormwater review is required)
[Site Development Permit isn’t required if project grading (cut plus fill) is under 10 cubic yards]
If the project results in 2,000 to 4,999 square feet of new plus replaced hard surface area, or, involves more than 7,000 square feet of land disturbing activity, then the required submittal is the Condensed Drainage Submittal.
If the project results in 5,000 square feet, or more, of new plus replaced hard surface area, and, if the value of the proposed improvements exceeds 50% of the assessed value of the existing site improvements; or, if the project converts 3/4 acres or more of vegetation to lawn or landscaped area, or, converts 2.5 acres or more of native vegetation to pasture, then the required submittal is the Full Drainage Submittal.