Allegheny County, PA Environmental Rules: Coastal Development (2026)

Allegheny County has no Atlantic, Gulf, or Great Lakes shoreline, so federal Coastal Zone Management Act (16 U.S.C. 1451) and Pennsylvania Coastal Resources Management Program (PA DEP, administered for Lake Erie and Delaware Estuary only) do not apply here. The functional equivalent is floodplain regulation for the Allegheny, Monongahela, and Ohio Rivers and their tributaries. The Pennsylvania Floodplain Management Act (Act 166 of 1978, 32 P.S. 679.101 through 679.601) and 12 Pa. Code Chapter 113 require every municipality with identified flood-prone areas to adopt and enforce a floodplain ordinance meeting National Flood Insurance Program standards. The FEMA County-Wide Flood Insurance Study for Allegheny County (effective September 26, 2014) maps the 1-percent-annual-chance (100-year) floodplain and floodways for the three rivers and the main draining streams. Etna Borough, the City of Clairton, the City of Duquesne, and Shaler Township have levee or floodwall systems within their jurisdictions. The City of Pittsburgh implements its FP-O Floodplain Overlay District under Title 9 Zoning Code Section 906.02, requiring the lowest floor of new construction or substantial improvement in AE Zones to be at or above the regulatory flood elevation (Section 906.02.J), and applying ASCE 24 design standards. The Allegheny County Act 167 Stormwater Management Plan (adopted May 31, 2018) catalogs each municipality's floodplain, stormwater, and SALDO ordinances in Table 10.6. The Southwestern Pennsylvania Commission Water Resource Center provides regional flood mapping support.