The Maryland Department of the Environment has provided advance notice of proposed revisions to the state’s stormwater management regulations and stormwater design manual. Written comments on the advance-notice version of the draft regulations and design manual will be accepted through December 19, 2025.
The advance notice comment period is an early opportunity for stakeholders and the public to provide input on potential updates to Maryland’s stormwater management regulations and design manual before they are formally proposed for final adoption. The final draft regulations and design manual will be the subject of another notice and comment period prior to adoption.
The drafts are the result of a multi-year work group and research process known as A-StoRM. (Advancing Stormwater Resiliency in Maryland)
Senate Bill 227 of 2021 directed MDE to review precipitation data every five years and make changes necessary to address the frequency and severity of storm events.
Additional context and background information can be found in MDE’s notice of rulemaking linked below and on MDE’s A-StoRM website linked here.
MDE’s notice of rulemaking is linked here.
The draft regulations are linked here.
The draft design manual is linked here.
NAIOP will submit a unified set of industry comments. Please forward your comments and recommendations to tom.ballentine@naiop-md.org. Comments may also be submitted directly to MDE via email at mde.swmregulations@maryland.gov.
MDE will hold a listening session at 10:00 am on November 13, 2025 in-person at MDE Headquarters (1800 Washington Boulevard, Baltimore, MD).