Christ Our King Presbyterian Church Cistern

What is polluted runoff?

Parts of the Chesapeake Bay watershed contain a high percentage of impervious cover – paved or other hard surfaces such as roofs and roadways that prevent rain water from being absorbed into the ground.  Instead, water runs along these surfaces, collecting trash and substances such as motor oil, lawn fertilizers, and pesticides.  This polluted stormwater flows into streams and rivers, where it threatens aquatic ecosystems and public health.  

Effective stormwater management, on the other hand, creates safe paths for polluted runoff to be captured and filtered through the ground before it reaches waterways.  This helps keep the environment clean and our communities healthy!

bioretention / rain gardens
before image
A new cistern captures roof runoff. Credit: Julia Poust, Chesapeake Conservation Corps.

after image
Church volunteers planted two rain gardens. Credit: Julia Poust, Chesapeake Conservation Corps.


Project Location: Bel Air, MD

Problem: This 50-year old church and school was plagued by periodic flooding due to high volumes of runoff from the roof and impermeable parking lot.  A small retention pond on site was failing during big rains, causing neighboring residential areas to flood. 

Solution:  By connecting existing gutters to a 1,500-gallon cistern, the church was able to capture roof runoff and mitigate overflow to the retention pond.  Additionally, with the help of 60 church volunteers, two rain gardens were installed, providing a myriad of benefits: beautification of the church property; water uptake and filtration; wildlife habitat; and an opportunity to strengthen the message of environmental stewardship with parishioners.  The garden absorbs 2,300 gallons of water per inch of rainfall, improving water quality in the Bynam Run watershed.  The church is now a certified Bay-Wise property via the Maryland Bay-Wise Program.

Scale: Runoff from 4,000 square foot roof

Funding sources: Chesapeake Bay Foundation; Chesapeake Bay Trust; Christ Our King Presbyterian Church

Partners: Chesapeake Bay Foundation; Chesapeake Conservation Corps; Harford Community College Senior Science Society; University of Maryland Master Gardeners

More information


Contact Information
Adrienne Shevchuk | | 410-268-8816
Key project facts
Project Type
Story Focus
Environmental Benefits
Community Engagement
Stormwater Funds
Problem Addressed
Failing Infrastructure
Flooding / Drainage
Runoff Pollution
Year Installed
State Legislative District
Federal Legislative District