Last year, the United Church of Christ of Seneca Valley received a $10,000 RainScapes rebate to design and construct a series of four rain gardens in a swale at the rear of the church. Guest blogger Bill Renner, Chair of Property Operations at the Church, discusses the process and how the congregation has responded!
The building that is home to the United Church of Christ of Seneca Valley building was constructed about 28 years ago on approximately 5 acres of gently rolling land. Overall, approximately 23 percent of the church property is covered by impervious surfaces such as building, driveways, parking lots and walkways.
In 1990, Montgomery County required the Church to construct a large stone- and sand-filled infiltration trench downhill and adjacent to the parking lot. This trench captures and filters most of the stormwater that flows across the parking lots.
In 2013, the church used a $10,000 RainScapes grant from Montgomery County to design and construct a series of four rain gardens in a swale at the rear of the building. These rain gardens capture runoff from adjacent areas. More importantly, they receive most of the stormwater runoff from the building’s roof via a system of buried PVC pipes connected to downspouts. The rerouting of roof runoff directly into the rain gardens also eliminated a significant problem with water accumulation along the rear of the building’s foundation.
Each rain garden consists of a basin surrounded by a berm with large stones placed at the outlet. Fortunately, the soil perked well (“perked” refers to a percolation test) in the area where the rain gardens were to be constructed, which kept costs down by enabling the contractor to amend the existing soil with mulch to a depth of three feet, on the surface of which were planted a variety of native plants. These plants were selected for their sturdy roots, sun- and drought-tolerance from a lengthy list that was provided by the County RainScapes staff.
Experience has shown that the rain gardens capture and retain all of the stormwater runoff from the roof for “drizzles” and smaller rainfall events. Because the rain gardens are deep and arranged in a series that are separated with grassy paths, only heavier rains produce any outflow, which is discharged across a broad, relatively flat grassy area and away from all structures.
The congregation’s response to the function and beauty of the rain gardens has been very positive. Some members of the congregation have volunteered to help periodically remove weeds from the rain gardens. Maintenance is an ongoing issue with weeding, replacing dying or damaged plants, and adding mulch as needed.
Visit DEP’s website to learn more about the RainScapes program.
Guest blog by Bill Renner, Chair of Property Operations, United Church of Christ of Seneca Valley