Watershed Regulations

Before starting any home improvement or landscaping project, it's essential to contact the relevant permit center to determine if your project requires a permit. If you live in Bellingham city limits or the urban growth area, please work with the City of Bellingham Permit Center. Otherwise, you will likely be working with Whatcom County Planning and Development Services.  

• City of Bellingham Permit Center: (360) 778-8300 or permits@cob.org 

• Whatcom County Planning and Development Services: (360) 778-5900 or pds@co.whatcom.wa.us 

Both the City of Bellingham and Whatcom County have strict rules to limit pollution from property maintenance, development, and construction. The specific rules and mitigation requirements vary depending on the jurisdiction, the type of surface being altered, and the size of the area being impacted. It is the homeowner's responsibility to contact the relevant permit centers to ensure their work abides by code. 

Your project may require specific mitigation depending on the type of surface you are altering. Examples include: 

• Hard surfaces: These are objects like rooftops, roads, and patios where stormwater cannot soak into the ground. When you alter these on your property, certain codes apply, requiring the homeowner to mitigate a certain amount of their property with projects that benefit runoff. In Whatcom County, for example, a new hard surface of over 200 square feet requires mitigation. Yet, in the City of Bellingham, mitigation is required for any new or replaced hard surface of 120 square feet or more. 

• Partially pervious surfaces: These include areas like lawns, non-native vegetated areas, and non-engineered pervious patios. Altering these surfaces may also trigger mitigation requirements. For example, in the City of Bellingham, these regulations apply to projects like replacing a lawn with mulch, installing a new deck over an existing lawn, or paving an existing gravel driveway. 

Since the regulations are complex and depend on the specifics of your project, always contact the appropriate permit center before beginning any work to ensure your project complies with all codes. 

Resources 

• Bellingham Municipal Code 15.42.060 

• Whatcom County Code 20.51.420 

• City of Bellingham’s Lake Whatcom Stormwater Guidance and Decision Flow Chart 

To protect water quality during the rainy season, both the City of Bellingham and Whatcom County restrict when ground-disturbing work can be done in the Lake Whatcom watershed. Ground-disturbing activities (like clearing vegetation, grading, filling, or exposing soils) can only happen from June 1 to September 30. All exposed soil must be covered by October 1 with mulch, rock, straw, or established vegetation. 

Small exemptions exist for gardening activities under certain conditions. Emergency work may also be approved when necessary to protect public health, safety, or the environment. Contact your local permit center to determine if your project qualifies for an exemption. 

Read More 

• Bellingham Municipal Code 16.80.120 

• Whatcom County Lake Whatcom Provisions 

Excess phosphorus is the primary pollutant harming Lake Whatcom's water quality. It fuels algal growth, which can harm fish and other aquatic life. To reduce excess phosphorus entering the lake, the City and County have rules about phosphorus content in yard products: 

• If you live in Bellingham: It is against the law to apply any fertilizer, mulch, or soil amendment that contains more than zero percent phosphorus on your property. When purchasing fertilizer, look for the '0' in the middle number on the fertilizer bag to ensure compliance. 

• If you live in Whatcom County: Commercial lawn fertilizer containing more than zero percent phosphorus cannot be used on residential lawns and public properties. 

Read your jurisdiction's code for additional details. 

Resources 

• Bellingham Municipal Code 15.42.050  

• Whatcom County Code 16.32.050 

Tree retention helps protect Lake Whatcom by filtering stormwater runoff before it reaches the lake. Both the City and County have specific requirements for retaining native trees and vegetation when developing property: 

• In the City of Bellingham: In addition to the city-wide Landmark Tree Protection ordinance which restricts the removal of trees over 36", City properties within the Lake Whatcom watershed must also retain a portion of native vegetation as part of stormwater management for new development, with different methods requiring different percentages of natural forest cover to be maintained. 

• In Whatcom County: A Tree Removal Permit is required for removing any tree on lots within the Lake Whatcom watershed, unless the removal is part of an approved development project. Trees that pose an immediate threat to person or property may be removed without review. 

Resources 

• Whatcom County tree removal webpage 

• Whatcom County Tree Removal Guide 

• City of Bellingham Landmark Tree Ordinance 

Septic systems that fail can pollute Lake Whatcom. All septic systems in the watershed must be approved and maintained according to Whatcom County Health Department requirements, regardless of whether you live in the City of Bellingham or unincorporated Whatcom County. For complete details on these requirements, visit Whatcom County's Septic System Maintenance page.

• Not sure if you live in the watershed? Check out our map! 

• Guidelines for Gardening Materials and Practices in the Lake Whatcom Watershed 

• Washington State Phosphorus Restrictions 

• Whatcom County Lake Whatcom Provisions 

• City of Bellingham Lake Whatcom Stormwater Guidance flowchart 

• Whatcom County's Septic System Maintenance page