The purpose of the current stormwater management ordinance (Chapter 151) is to restore, enhance, and maintain the chemical, physical, and biological integrity of streams; minimize damage to public and private property; and reduce the hydrologic impacts of land development. Stormwater management is accomplished by using environmental site design (ESD) practices to the maximum extent practical (MEP) to maintain runoff characteristics and reduce stream channel erosion, water pollution, groundwater depletion, and local flooding.

In September 2001, Carroll County adopted ordinance 01-12 which required four levels of stormwater management control: water quality, groundwater recharge, channel protection, and ten year peak management. Structural methods, such as ponds, or non-structural methods, such as ESD practices, were used; however, structural methods were only used as a last resort.

In April 2004, the stormwater management ordinance was revised to require the use of non-structural methods to reduce the number and size of ponds deeded to the County for perpetual maintenance. The current ordinance, adopted in April 2010, was written to adopt the State of Maryland revisions to the design manual which mandated the use of non-structural ESD practices statewide to the MEP to mimic totally undeveloped hydrologic conditions.

This chapter applies to all new development projects which cumulatively disturb more than 5,000 square feet of land area. It may also apply to smaller projects if downstream problems exist from runoff created by development.

If additional information is needed, please contact the Bureau of Resource Management at 410-386-2712.