SM Retrofit - Roads (P801300)

  • Category: Conservation of Natural Resources

  • Sub Category: Stormwater Management

  • Administering Agency: Environmental Protection (AAGE07)

  • Planning Area: Countywide

  • Date Last Modified: 4/21/14

  • Required Adequate Public Facility: No

  • Relocation Impact: None

  • Status: Ongoing





This project provides for the design and construction of Environmental Site Design (ESD)/Low Impact Development (LID) stormwater management devices along County roads constructed prior to modern stormwater management controls. ESD/LID stormwater devices include bioretention, curb extensions, porous concrete, tree box inlets and other types of devices that promote water filtering and groundwater recharge.

Cost Change

Increase due to an increase in the amount of retrofit projects beginning in FY15 and the addition of FY19 and FY20 to this ongoing project.


This project supports the requirements of the MS4 permit and addresses the goals of the Chesapeake Bay tributary strategy initiative, and the County's adopted water quality goals (Chapter 19, Article IV). The County's MS4 permit requires that the County provide stormwater controls for 20 percent of impervious surfaces not currently treated to the maximum extent practicable, with an emphasis, where possible, on the use of ESD/LID devices. This project will be responsible for controlling stormwater on County roads, largely through ESD/LID practices, as needed to satisfy the permit requirements.


A portion of these potential ESD/LID stormwater retrofits on County roads were previously programmed under the SM Retrofit - Government Facilities project (No. 800900). This new stand alone project includes all the potential ESD/LID projects for County roads and allows for a more efficient implementation of projects of similar scope in partnership with the Department of Transportation (DOT). Planned and inconstruction projects include Amherst Avenue, Breewood Neighborhood Green Street, Dennis Avenue DOT Participation, Donnybrook LID Retrofit, Franklin Knolls DOT Partnership, and Sligo Park Hills Neighborhood Green Street.

Fiscal Note

While the State of Maryland has indicated a desire to provide funding, all indicated State Aid is preliminary and unappropriated in FY15-20. Funding may need to be revised based on the actual State Aid commitments.


Expenditures will continue indefinitely.

The Executive asserts that this project conforms to the requirements of relevant local plans, as required by the Maryland Economic Growth, Resource Protection and Planning Act.


Department of General Services, Department of Transportation, Maryland-National Capital Park and Planning Commission, Department of Permitting Services, Maryland Department of the Environment, United States Army Corps of Engineers, Maryland Department of Natural Resources.