Calvert County, MD Environmental Rules: Stormwater Management (2026)

Section 123-5 sets the chapter's core mandate: no one may develop land for residential, commercial, industrial or institutional use without providing stormwater management measures consistent with the county's Design Manual, except as the chapter allows. Exemptions cover agricultural land management, additions to existing single-family homes meeting the size test in § 123-6(C), any project disturbing 5,000 square feet or less, and activity the state separately regulates (§ 123-6). Before any grading or building permit issues, the Department of Public Works must approve a stormwater management plan, and, where applicable, the applicant must record easements for the facility and its inspection access, sign a maintenance agreement, and post a performance bond sized to the estimated construction cost (§§ 123-16, 123-20, 123-24).

A nonrefundable review and inspection fee equal to 2% of estimated construction cost, with a $200 minimum, is due when the plan or a waiver application is submitted; waiver review alone costs $50 (§ 123-17). The Director enforces the chapter through written notices of violation, stop-work orders, and injunctive relief (§ 123-35), and any violating condition is separately declared a public nuisance subject to abatement at the violator's expense (§ 123-36). Appeals from a permit denial or notice of violation go to the Board within 30 days, then to the Circuit Court of Calvert County (§ 123-40).