The Department of Ecology funded a three-year program to assist residents in the Lake Whatcom Watershed with capturing and infiltrating rain water to reduce stormwater runoff. A total of 166 residential homes participated in the RSRP with 330, 95-gallon rain barrels installed.
Approximately 3.9 million gallons of stormwater per year is diverted from direct discharge into the infrastructure and is made available to be infiltrated or dispersed on-site. The average participating Lake Whatcom home was able to capture 42% of roof runoff into and through rain barrels. This project captures rainwater from approximately 8% of all available roof area within the City’s portion of the Lake Whatcom Watershed.
Development requires a stormwater drainage system to control runoff from impervious surfaces. However, the unintended consequences include erosion, pollutants such as phosphorus entering the water bodies of our watersheds and disruption to wetland and stream functions.
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.
Approximately 1,000 single-family residences are within the Residential Stormwater Retrofit project area (320K PDF) and were eligible for a rain barrel retrofit. The Homeowner Incentive Program continues to offer Lake Whatcom Watershed opportunities for stormwater infiltration through December 2014.
In addition to the focus on Lake Whatcom, the RSRP also used rain barrel systems to address city-wide stormwater issues. Some downspouts on homes in older neighborhoods combine stormwater with wastewater in the sewer system. Rain barrels were used to collect and divert the stormwater away from the sewer, helping reduce peak flows and treatment costs at the Post Point Wastewater Treatment Plant. Separating rain water from wastewater also reduces maintenance costs of the entire sewer system.
Benefit to eligible homeowners:
The city’s commitment to the project included:
The homeowner's obligation to the project:
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.