Overlook Elementary School in Abington Township is bounded to the north by the Sandy Run, the single largest tributary to the Wissahickon Creek and one of its most degraded. The area is surrounded by residential neighborhoods and is the most upstream reach of the Sandy Run – the stream begins right in this neighborhood at a stormwater drain off of Corinthian Avenue and is considered the headwaters. The banks of the Sandy Run are eroding and the stream itself is most often dry but floods quickly when it rains, flooding nearby resident’s yards. Because of the large volume of polluted stormwater the stream receives from the area, it struggles to support a healthy aquatic ecosystem. Ideally, small streams like the Sandy Run foster healthy aquatic insects, amphibians, and fish, which have positive ecosystem impacts up the food chain.
To improve the health of the Sandy Run, we are working with Abington School District to install green stormwater infrastructure (GSI) at Overlook Elementary School. Features like rain gardens will slow down and retain stormwater running off of the school’s parking lot and fields. Managing stormwater with natural features such as plants, rocks, and areas for water to pool will reduce erosion of the stream, reduce flooding during storms, reduce pollutants in the stream, and improve groundwater recharge so that the stream flows more consistently throughout the year.
There are four main features planned at Overlook Elementary School:
In the fall of 2021, volunteers from the community planted over 100 native plants and shrubs on the banks of the Sandy Run. Shrubs and vegetation on the stream banks will help hold soils in place to reduce erosion and filter pollution.
A rain garden is a garden with deeply-rooted plants that captures stormwater and filters polluted runoff before stormwater gets to the stream. When it rains, a rain garden will fill with water and the water-loving plants will absorb water and increase infiltration into the ground. Within two days after a storm, the rain garden will be dry again. Slowing down and absorbing water in the rain garden reduces flooding of the nearby stream and recharges groundwater. Water from the school’s parking lot will be captured in a large rain garden on the west side of the athletic fields.
A bioretention basin is planned to the north of the school’s athletic fields. This feature is a long, narrow garden planted with deep-rooted plants that filters polluted runoff, similar to a rain garden. The bioretention basin will run parallel to the stream and will intercept stormwater running down the athletic field, with the goal of catching polluted runoff and slowing down and absorbing stormwater to reduce the flooding and pollution of the creek.
A step pool will be installed at the stormwater inlet at the corner of Silver Avenue and Cleveland Avenue. This stormwater inlet receives a rush of water from the street and residential area during storms that gushes to the stream with high volume and intensity. The step pool will feature large stones that will slow down the water speed and allow some water to infiltrate into the ground.
Wissahickon Trails and Cerulean LLC are managing this project, and Gessler Construction and Abington Township will manage installation. This project is currently projected to begin in early August and will be completed by the time students are returning to school.
Please contact Erin Landis at email@example.com if you have any questions or concerns.