Buffers are vegetated lands adjacent to critical areas that are intended to protect the critical areas from activities occurring beyond the buffer. Land use regulations have required buffers around wetlands and streams for a number of years and buffers have been the subject of many scientific studies and reviews. Buffers serve different functions depending on the type of critical area they are intended to protect.
Standard Width Determination
Standard buffer width is based on the following factors:
Wetland Category: Category I wetlands have the largest buffers
Habitat Function Score: High quality habitat is valuable and protected with a larger buffer
Land Use Intensity: Wetlands adjacent to high intensity land use require larger buffers for protection
In some instances buffers prescribed by the regulations cannot be met on a particular site. When this occurs there are a series of options available to landowners to comply with the regulations, such as:
Wetland quality will be based on a rating system that is easy to review and ensures all wetlands are evaluated using the same criteria. It also improves consistency with state regulations. Wetland categories are assigned based on the Western Washington Wetland Rating System (PDF).
Category I wetlands are of exceptional value in terms of protecting water quality, storing flood and storm water, and/or providing habitat for. These are wetland communities of infrequent occurrence that often provide documented habitat for sensitive, threatened or endangered species, and/or have other attributes that are very difficult or impossible to replace if altered. Buffer 50-300 feet.
Category II wetlands have significant value based on their function. They do not meet the criteria for Category I rating but occur infrequently and have qualities that are difficult to replace if altered. Buffer 50-275 feet.
Category III wetlands have important resource value. They occur commonly in Whatcom County. Buffer 50-150 feet.
Category IV wetlands are of limited resource value. They typically have vegetation of similar age and class, lack of special habitat features, and/or are isolated or disconnected from other aquatic systems or high quality upland habitats. Buffer 25-50 feet.
Larger buffers for large streams and rivers with ﬁsh habitat (150-feet)
Buffers for medium sized ﬁsh-bearing streams are smaller (100-feet)
Still smaller buffers for non-ﬁsh bearing streams (50-feet)
Buffers for rivers and streams with channel migration zones
Wildlife habitat buffers specify how development is regulated within sensitive wildlife habitats including allowed encroachments, prohibitions, and when wildlife studies are required. Wildlife and habitat buffers vary by species and type.
Geologically Hazardous Areas
Geologically hazardous area buffers restrict development in alluvial fan hazard areas. Protections now include tsunamis, volcanic hazards, and erosion hazards. Buffers associated with geologically hazardous areas are primarily designed to protect property and human life from hazards associated with certain unstable geological conditions. Buffers adjacent to steep slopes can increase stability and ensure that people and structures are protected in the event of a landslide.