Floating wetlands could boost Charles River restoration
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Artificial wetlands like the one in the Charles River can remove phosphorus from polluted urban waterways, create new habitats for fauna and beautify some of the muckier parts of our rivers.
Why it matters: Urban rivers like the Charles face mounting pressures from nutrient pollution and climate change.
- The Charles River Conservancy wants to expand a pilot program that puts hydroponic islands full of wetland plant life along the river's banks and into the Broad Canal in Cambridge.
What they're saying: "It has so many benefits, not only in being able to help make the water quality healthier by contributing to phosphorus removal, but it also brings back so many plants and animal species, really contributing to the biodiversity of our city," executive director Laura Jasinski told Axios after a recent paddle to the island from Broad Canal.
Yes, but: Expansion requires regulatory recognition and a surge in funding.
- "You could imagine a floating eco-park in the Broad Canal as a huge destination for so many folks, something you could enjoy on your lunch hour, or something you might travel a really long way to see," Jasinski said.
By the numbers:
- One 700-square-foot pilot island is already installed in the Charles River by the Longfellow Bridge.
- 2 grams of phosphorus can be removed per square meter annually by wetlands like the pilot project in the Charles.
- 19 native plant species were successfully planted in the man-made hydroponic island.
The big picture: Researchers in Boston, Chicago and Baltimore found floating wetlands remove phosphorus at a rate comparable to landscaped rain gardens while encouraging new animal habitats and urban green space.
What they found: Researchers report the environment around the floating wetland looked more like the kind of healthy water body conservationists want the Charles to become.
Between the lines: The pilot program island also succeeded as an engagement platform.
- "So many of the young people we work with, even if they've lived in Boston and Cambridge their entire lives, getting out to the Charles as part of a field trip is their first interaction with the river up close."
What's next: The Charles River Conservancy is eyeing Broad Canal in Kendall Square for expansion.
- Early plans call for a 1-acre installation that could offset phosphorus from 7–15 acres of surrounding urban development.
- The confined lagoon at the Broad Canal receives direct stormwater discharge and experiences frequent algal blooms.