Standards are specific to each of the watershed overlay zones and vary by watershed. In general the regulations are low impact development standards that are intended to protect a valuable resource, whether it be drinking water or aquatic habitat. For a full list of requirements and standards related to the Birch Bay and Drayton Harbor watersheds please see Whatcom County Code Title 20.
Stormwater Special Districts
As described by WCC 20.80.635, the Birch Bay and Drayton Harbor watersheds are listed as Stormwater Special Districts.
On-Site Stormwater Facilities. On lots less than five acres, single family homes and duplexes are required to install permanent on-site stormwater quantity and quality facilities for:
- New construction or remodels that increase impervious surfaces by more than 500 square feet; or
- Renovation projects where the estimated cost of the work exceeds 50% of the assessed value of the existing structure.
Protected Native Growth Areas. On lots larger than two acres, but less than five acres, 65% of a site must be set aside and dedicated as a Protected Native Growth Area (PNGA) if dispersion stormwater facilities are used (please see Section 221 of Whatcom County Development Standards). A PNGA shall preserve existing forested areas, vegetation, and critical areas.
Water Resource Special Management Areas
As described by WCC 20.80.735, these areas include the Birch Bay and Drayton Harbor watersheds. In these areas, the following actions are required:
Temporary Erosion and Sediment Control measures (e.g., silt fences, check dams, mulching) must be installed and inspected prior to any regulated clearing activity.
Soil Stabilization. All disturbed areas must be stabilized with approved erosion and sediment control measures within two days of disturbance.