Rain gardens beautify local church

October 30, 2014

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!

Dealing with Stormwater

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.


A Rebate from RainScapes

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.


Buried downspouts redirect the flow of water

PVC pipes were connected to the downspout and buried to carry the water away from the building.

Percolation Test

The site of a percolation test, performed prior to construction to test the permeability of the soil.


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.


Rain gardens during construction

The existing soil was improved with the addition of mulch.


The Final Result

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


The final rain gardens

The rain gardens are beautiful additions to the church property!


2 comments on "Rain gardens beautify local church"

  1. john austin says:

    nice project, Green Gardens Inc. was glad to have been a part of it. I am amazed at the effectiveness of these gardens. The rain that fills them does not stay on the surface for more than a day. All is sucked into the soil immediately. we may have some photos t share that show before and after with water in them.

    1. Gwen Bausmith says:

      Thanks for the comment, John! We would love to see any before and after photos you may have. Those are always popular images to post on our social media sites. If you find any that you want to share, feel free to email them to us at AskDEP@montgomerycountymd.gov.

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