Chris Brooks presented on McCormick Taylor’s Parking Lot E project at the Chesapeake Water Environment Association’s (CWEA) Spring Stormwater Seminar on May 18.


Held at the Maritime Institute of Technology and Graduate Study in Linthicum Heights, MD, this year’s CWEA Spring Stormwater Seminar provided attendees the opportunity for peer-to-peer information exchange with representatives of regulated stormwater programs.


Read the presentation’s abstract below:


Ellicott City’s Historic District is a Main Street community located between steep slopes in Maryland’s Patapsco River Valley. Inspections of the town’s infrastructure following the August 2011 mid-Atlantic-shaking earthquake revealed that Parking Lot E’s retaining wall needed repairs. A month later, Tropical Storm Lee flooded Ellicott City damaging homes, stores, and county infrastructure, including additional damage to the Lot E retaining wall.


Howard County hired McCormick Taylor to design and construct a solution to Lot E’s failing retaining wall with the additional objectives of improving access to parking, increasing pedestrian safety, and beautifying Parking Lot E, all while incorporating the treatment of nearly two acres of previously unmanaged upland impervious surface draining from the Circuit Court complex.


Stormwater is now managed through a series of BMPs. Treatment begins with the majority of water from the courthouse area entering a flume leading to a multi-tiered bioretention treatment train. Water enters into the flume and is conveyed down a step pool feature to a forebay, where it is carried beneath the stairway into the first bioretention cell. When full, the first cell flows over into a second bioretention cell via a weir waterfall that doubles as an aesthetic feature. The second cell also utilizes an aesthetic waterfall feature as an overflow. A tree box filter placed along the edge of the parking lot catches water off of Lot E itself. An additional bioretention located at the north end of the lot catches runoff that bypasses the staircase treatment facilities. Densely planted native species uptake nutrients in the runoff while providing year round aesthetic value and supporting native wildlife.


The Lot E Staircase and Water Quality Project utilizes a unique combination of LID practices in a treatment train, beautifies an adjacent parking lot, and overcomes urban infrastructure challenges while treating stormwater and improving walkability. The design allows pedestrians a safe and well-lit path not only to the vast parking lot located less than 0.2 walking miles from Main Street, but also to resources and infrastructure such as the Howard County Historic Society Museum, the Ellicott City Wellness Center, the Circuit Courthouse, and several small business. This staircase and parking lot improvements that incorporate bioretention in the design not only provides improved human access but also creates an opportunity to educate both visitors and locals that managing stormwater is a fundamental part of urban infrastructure that can be both functional and aesthetic.