Portland, ME Environmental Rules: Erosion Control (2026)

4 of the Land Use Code's Shoreland Overlay Zone article governs grading, filling, excavation and similar soil-disturbing activity within 250 feet of the normal high-water line. Any such activity that requires a permit and produces unstabilized soil conditions must be covered by a written soil erosion and sedimentation control plan, prepared to the standards of the Maine Erosion and Sediment Control Handbook for Construction: Best Management Practices, published jointly by the Cumberland County Soil and Water Conservation District and the Maine DEP, and to the City of Portland Technical Manual.

The plan goes to the review authority for approval and must address mulching and revegetation, temporary runoff controls such as hay bales or silt fencing, and permanent stabilization structures such as retaining walls or riprap. Development must be designed to fit the site's topography, avoiding steep slopes requiring high cuts and fills wherever possible. Any exposed ground must be stabilized, temporarily or permanently, within one week of last being actively worked, using riprap, sod, seed or mulch, with mulch applied at a minimum of one bale per 500 square feet; permanent stabilization is required within nine months of initial exposure.

Where an excavation contractor's work causes more than one cubic yard of soil disturbance, a Maine DEP-certified erosion-control practitioner must be present on site every day earth-moving occurs, with that person's name and certification number listed on the permit application; agricultural and timber-harvesting activities using best management practices, and government employees on public projects, are exempted.