What is a wetland?
As defined in the Mercer Island municipal code, a wetland is: "Areas that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support, and that under normal conditions do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands do not include artificial wetlands, such as irrigation and drainage ditches, grass-lined swales, canals, landscape amenities, and detention facilities or those wetlands that were unintentionally created as a result of the construction of a road or street unless the artificial wetlands were created to mitigate the alteration of a naturally occurring wetland" (MICC 19.16.010).
Are any wetlands exempt from City regulation?
Wetlands of less than 2,500 square feet are exempt from City regulation. However, this exemption does not cover applicable state and/or federal permit requirements. (MICC 19.07.080) Applications with identified probable wetlands should contact the Army Corps of Engineers.
What are the restrictions for wetland projects?
The following conditions are applicable for wetlands of 2,500 square feet or greater (for more detailed information see MICC 19.07.080).
- No building pad is permitted in the wetland area or buffer
- No impervious surfaces are permitted in a wetland area or buffer
- Projects requiring more than 500 cubic yards of fill in a wetland area shall be reviewed under the State Environmental Policy Act.
- Special regulations apply to wetlands associated with Shorelines of the State.
This information is summarized from Title 19 of the Mercer Island City Code, "Unified Land Development Code" and is provided for quick reference only. To determine exact requirements, and for other development regulations affecting a parcel or lot, Title 19 should be consulted.