Since 1998, Lake Whatcom has been on Ecology’s 303(d) list of impaired water bodies in the state due to low levels of dissolved oxygen resulting from increases in phosphorus. A Total Maximum Daily Load (TMDL) study for Lake Whatcom conducted by the Department of Ecology recently identified where pollution needs to be reduced and by how much.
Development in the Lake Whatcom Watershed requires a stormwater drainage system to control runoff from impervious surfaces. However, this also has unintended consequences in that runoff carries pollutants like phosphorus into the water bodies of our watersheds. The system also has difficulty handling peak-season stormwater flows during fall and winter, causing erosion where excess soil is deposited into the water, disrupting wetland and stream functions. Roofs, parking lots, and other impervious surfaces contribute significantly to development runoff in both quantity and velocity. Native soils of the Pacific Northwest are capable of completely soaking up normal rainfall. Several stormwater-related problems would be eliminated if developed sites functioned the same way.
The Residential Stormwater Retrofit Program takes an approach that will aid in reducing flows into ditches and creeks by retrofitting homes in the watershed with rain barrels. Catching rainwater can help reduce or eliminate stormwater runoff from rooftops that can contribute to water quality degradation, pollution, and erosion. Retrofitting homes with rain barrels will help detain stormwater flows and slowly release the water from the collection system back into the soil for infiltration. This is especially beneficial during the rainy months from November to May.
Approximately 1,000 single-family residences are within the Residential Stormwater Retrofit project area (320K PDF) and are therefore potentially eligible for a rain barrel retrofit. Funding for the program is available to retrofit approximately 325 homes. The average roof square footage for these homes is approximately 2,000 square feet. With average rainfall in the watershed totaling approximately 43 inches per year, each of these residences potentially generates about 45,000 gallons of roof rainwater runoff annually.
Benefit to eligible homeowners:
The city’s commitment to the project includes:
The homeowner's obligation to the project:
Rain barrels for the first year of the project can hold 95 gallons each, built by Cypress Designs under a contract with the City of Bellingham. Once installed, the rain barrels can be painted and become the property of the homeowner.
Homeowners should consult the Residential Stormwater Retrofit Program map to determine if their home is located in the project area. If so, please contact a Residential Stormwater Retrofit Program representative at (360) 778-7700 or email stormline@cob.org. Please provide preferred contact information and home address to be considered for the program. Participation is on a first come, first serve basis. Some homes may not be suitable for rain barrels, which will be determined during a site evaluation by city staff.
Rainwater collection is not a new concept. For thousands of years, people have been using collected rainwater in areas where water is scarce or unsafe to drink. This simple technology continues to be used today around the world to provide water for drinking and irrigation, and more recently, stormwater control. Rainwater catchment systems (e.g. rain barrels) collect and store rainwater from your roof that would otherwise be lost to runoff that is diverted to storm drains, streams, and lakes. It can be used in residential, commercial or industrial development for new or remodel projects. Catchment systems vary in size from simple 55-gallon rain barrels to more sophisticated 10,000-gallon tanks.
For the first year of the program, the city will be installing 95-gallon, rain barrels from a local manufacturer. Barrels are constructed out of high-density polyethylene, (minimum of 10% recycled content) and can be painted with regular latex house paint and plastic primer. Barrels contain two hose bibs, a screen to prevent debris from entering, and an overflow system. Systems are reinforced for stability and have a space-conserving design, where they fit against the corner of a house.
A hose will be attached to each rain barrel leading to a drip hose placed in landscape beds. This will provide infiltration during winter months. Seasonally the drip hose valve may be turned off to allow rain water storage for irrigation use.
