The construction of 36 rain gardens will help filter water pollution in downtown Bellingham and is set to start the beginning of May, said Rose Lathrop, green building and smart growth manager for Sustainable Connections.
Rain gardens sit slightly below street level and use sidewalk curves as gutters to funnel street runoff into planted areas that range in size and shape, said Freeman Anthony, City of Bellingham project engineer.
As the gardens collect water, plants, layers of soil and rock filter absorb storm water to clean and purify, Anthony said.
The City of Bellingham already has a rain garden on North State Street and hopes the new rain gardens will revitalize downtown while reducing the negative affects that urban areas have on storm water.
The accumulation of oil breaks dust and other harmful pollutants, Lathrop said.
Rain gardens can help reduce pollution by mimicking natural processes in an urban environment, Anthony said. Rainwater runoff from downtown streets goes straight into storm drains and then usually back into Whatcom Creek.
There are catch basins at the drain bottoms that capture large particles such as debris and trash before the water re-enters the natural system, Anthony said.
Unfortunately, these catch basins don’t stop any of the soluble or dissolved pollutants from re-entering the stream and eventually the bay, Anthony said.
One of the soluble pollutants is fecal coliform, which is a bacterium that
can come from dog waste, among other things, Anthony said.
This method of runoff management also releases warmer water back into the creek, Anthony said.
All of these problems are factors in the declining health of Whatcom Creek which is listed as an impaired water way for two reasons; it has too much fecal coliform and too high of a temperature, Lathrop said.
“[Rain gardens] clean the water up and cool it down a little, rather than just running it off a hot road right down into the creek,” Anthony said.
The gardens are a potential solution to runoff from roadways and could minimize pollution in the Puget Sound, Stangl said.
“The main reason [the city] is putting them in is for storm runoff but they can also contribute to the aesthetics of the environment and make a nicer streetscape, Stangl said.
Not only will rain gardens help revitalize the creek, but those involved with the project hope the gardens will help energize downtown, Lathrop said.
Lathrop hopes new greenery on the street corners will bring more life and vibrancy to downtown, he said.
The planning team hopes that people see both the environmental and aesthetic purposes of the gardens
them both functional and looking nice, Anthony said.
During construction, Rain gardens will be built on parking strips near crosswalks at street intersections, from North Garden to York.
While the intersections are under construction, the city will work on pedestrian safety improvements at major downtown intersections, Anthony said.
Curbs around the intersections will extend out to reduce traffic exposure for pedestrians, and crosswalk ramps will improve to help the visually impaired and those with wheelchairs or strollers, Anthony said.
Construction is scheduled to start either at the end of April or the beginning of May, Lathrop said.
If things go as planned, the project will be complete by the first week in June, Anthony said.
No set construction timeline exists for each intersection yet, but a similar project on the corner of Cornwall and Maple took about two weeks to complete, Anthony said.
Pedestrians may have to use different sidewalks and may be redirected via detours during construction, Anthony said.