Interior Code Requirements in Maryland

State-mandated protection zone for all land and water areas within 1,000 feet beyond the landward boundaries of tidal wetlands, the Chesapeake Bay and its tributaries. Established by the Chesapeake Bay Critical Area Act of 1984.

FEMA-designated flood zones throughout Maryland. All 24 jurisdictions participate in the National Flood Insurance Program (NFIP). Extensive tidal flooding along Chesapeake Bay, Atlantic coastal flooding in Worcester County, Potomac River flooding, and flash flood risk in urbanized areas. Ellicott City experienced catastrophic flash floods in 2016 and 2018, prompting enhanced local flood mitigation.

Maryland has extensive historic preservation requirements at state, county, and municipal levels. The Maryland Historical Trust (MHT) reviews projects involving state funds or permits. Major districts include: Annapolis (National Historic Landmark District — one of the largest colonial-era districts in the US), Baltimore (Federal Hill, Fell's Point, Mount Vernon, Bolton Hill, and 30+ additional districts under CHAP), Frederick (50+ blocks, 2,000+ properties), Easton, Ellicott City (with flood mitigation overlay), St. Mary's City (1634 colonial capital), Chestertown, Havre de Grace, and Cumberland.

Most of Maryland is Seismic Design Category A or B. The state has low seismic risk but is not immune to earthquake effects — the 2011 M5.8 Mineral, Virginia earthquake was widely felt across Maryland and caused minor damage. Eastern Shore counties on soft coastal plain soils may have amplified ground motions. Standard IRC seismic detailing is generally adequate, but site-specific analysis recommended for Site Class E or F soils.

State floodplain management requirements for riverine (non-coastal) flood zones. Local jurisdictions may have stricter requirements.