The stormwater management program is a state mandated program delegated to Harford County on September 6, 1984. Historically, runoff from development was only managed during the construction phase of a project through sediment control practices. Stormwater management structures, or best management practices (BMPs) were developed to manage stormwater runoff after the construction phase of the project has been completed. Examples of BMPs are infiltration, flow attenuation, retention, extended detention, and detention.

All new development in Harford County must address stormwater management by obtaining either an exemption or a waiver from stormwater management requirements, or by providing management though environmental site design (ESD) or by the construction of a BMP. Water Resources Engineering is responsible for the review and approval of stormwater management waivers, exemptions, and design plans.

Development that requires stormwater management must utilize ESD to the maximum extent practical to address water quality, groundwater recharge and channel protection. In addition peak discharges must be controlled to a level equal to or less than the existing runoff for the 10 year storm event. Areas within two watersheds in the County must also provide 100 year management. These two areas are the Bynum Run watershed above Business Route 1 and the Wildcat Branch watershed above Reckord Road.

As part of the stormwater management program, an engineer in charge is required to inspect each BMP during construction and determine whether the facility is constructed to specifications. The Bureau of Water Resources is also required to conduct maintenance inspections for each BMP on a tri-ennial basis. Currently, there are approximately 900 BMPs within Harford County.

The Maryland Department of the Environment (MDE) reviews Harford County’s Stormwater Management Program on a tri-ennial basis to determine if the County’s program is in compliance with the mandated requirements.