Protecting Lake Champlain at Shelburne Community School

Jul 17, 2019
Blog Mmi Shelburne Community School Lake Champlain M 2019

Shelburne Community School, Lewis Creek Association, and the town of Shelburne have partnered to actively improve water quality of stormwater running off the school property and flowing to Lake Champlain.

Following the last day of school, a bioretention area, also known as a raingarden, was constructed outside the school entrance in the center island. This mostly lawn area was transformed into a depression filled with attractive plants that filters pollution out of water before it gets to McCabe’s Brook. Students at the school worked with the Lewis Creek Association, water resource engineers and school staff to help identify areas where stormwater improvements could be made. The entrance area was identified as the most important location that could collect dirty water running off of paved surfaces. Engineers and watershed stewards will be visiting the school classrooms in the fall to teach the students about watershed science and the stormwater improvements.

All of the stormwater runoff from the Shelburne Community School property flows into McCabe’s Brook and Shelburne Bay; Lower McCabe’s Brook is listed as a state impaired surface water for aquatic life support due to nutrient pollution. The brook also has documented erosion problems and elevated turbidity and nutrient concentrations during base flow conditions (South Chittenden River Watch/VT DEC, 2016). Nutrients like these can cause serious algal blooms (including harmful blue-green algae) in the lake, and can lead to fish die-offs. Chloride (which is in road salt, sodium chloride) is also bad for the environment and can kill off plants. Currently, runoff from the Shelburne Community School roof, parking lots, driveways, playgrounds and fields is collected in a series of swales, catch basins and pipes that drain to the west and directly discharge into McCabe’s Brook and Shelburne Bay. At many campus locations, runoff travels directly from an impervious surface to an aging pipe network with no treatment. The town of Shelburne has been listed as stormwater impaired, so action on a large scale is critical to retract impairment status and reduce the large amount of nutrient-rich stormwater directly entering into McCabe’s Brook, then Shelburne Bay.

Lewis Creek Association was awarded a grant in 2017 from the Lake Champlain Basin Program to finish construction design plans and implementation of a rain garden on the Shelburne Community School campus. This bioretention area, in the center of the circle where busses drop off children, was calculated to drain and filter 0.7 acres of land, 36 percent of which is impervious surface (and highly trafficked, and likely to have high chloride concentrations from road and sidewalk salt use). This type of bioretention area would reduce flows and pollutant inputs discharging to McCabe’s Brook (which then enters Shelburne Bay approximately 1 mile downstream).

As part of the project, school visits with fourth graders were completed, and students were taught lessons about the water cycle, watersheds, how stormwater moves and the plan for the rain garden.

An engineering firm (Milone & MacBroom) was selected, the final design for the bioretention area was completed and bids for construction were acquired. All bids were over budget, so the Lewis Creek Association obtained the support of the Shelburne Highway Department to assist with portions of construction to reduce costs. Construction was scheduled to occur in the fall of 2018, but weather events (rain, snow, and extended freezing temperatures) prevented scheduled construction.

Read the original article here.

(c) Shelburne News, 2019