Seminole County Erosion & Stormwater Regulations: A Quick-Reference Guide

Construction sites disturbing one or more acres in Seminole County are generally subject to FDEP's NPDES Construction Generic Permit, which requires an approved SWPPP identifying the BMPs that will keep sediment on site. On top of that state permit, the county's MS4 (Municipal Separate Storm Sewer System) program and local stormwater plan review can add jurisdiction-specific requirements, and projects inside incorporated cities — Sanford, Lake Mary, Oviedo, Winter Springs, Casselberry, and Altamonte Springs — may face additional city-level review.

Because the applicable review path depends on where a parcel sits and what's been approved for it, the right move on any given site is to confirm the specific permit and plan requirements before work begins rather than assuming a 'standard' process applies.

The western part of Seminole County falls within the Wekiva River basin, a designated Outstanding Florida Water with heightened protection standards — sites draining toward it can expect closer scrutiny on sediment control. Much of the rest of the county drains toward Lake Jesup, Lake Monroe, and the St. Johns River. Sandy soils dominate, but flatwoods and wetland-adjacent parcels are common, which raises the stakes on correctly sized inlet protection and sediment basins.

Sites near the Wekiva basin, Lake Jesup, or Lake Monroe should budget extra lead time for permit review and plan on tighter BMP performance margins. For everything else, the main risk is treating county and state requirements as interchangeable — confirming the local jurisdiction's specific review process up front avoids rework later.