Stormwater Engineering Regulations
Runoff from impervious surfaces affects local streams by increasing erosion along stream banks, silting in stream beds and depositing trash in waterways. The cumulative effect is a reduction in water quality, aquatic resources and the health of streams and the Chesapeake Bay. To improve the effects of storm water runoff, and thereby improve the quality of the Chesapeake Bay, the Maryland legislature passed the Storm Water Management (SWM) Act of 2007. Baltimore County has revised its Code to incorporate these State-mandated changes. This is under Article 33 Title 4 and is available to view on the County's web site or a copy of Title 4 (PDF) can be downloaded here.
This Act significantly affects the design of storm water components for land development projects. Some of the more significant changes are:
- Environmental Site Design (ESD) to the Maximum Extent Practicable (MEP) must be addressed for all projects, including redevelopment.
- Three sequential plan submissions and reviews are now required: Concept SWM Plan; Development SWM Plan; and Final SWM Plan.
- Redevelopment projects will require 50 percent reduction in impervious surface or equivalent water quality management. Currently the requirement is 20 percent.
- No grading or building permits may be issued until sediment control and SWM plans are signed.
To review the COMAR revisions and become familiar with all the changes to the Design Manual, visit the The Maryland Department of the Environment's web site.
Revised June 7, 2011
