Nassau County, FL Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing law
- Roadway and Drainage Standards Ordinance, Appendix D Article 10
- Permit trigger
- Alters drainage, land use, structures, or new subdivision
- Reviewing agency
- Engineering Services / Development Review Process
- Single-family exemption
- Only if not part of larger development plan
- Minor-project retention
- First 1 inch of rainfall retained or detained onsite
- Engineer requirement
- Plans sealed by a Florida-registered engineer
Summary
In unincorporated Nassau County, any project that alters natural or man-made drainage collection, storage or conveyance systems, changes land use, adds or resizes structures, or creates a new subdivision must get prior approval through the county's Development Review Process under the Roadway and Drainage Standards Ordinance. Engineering Services reviews plans against Article 10's flood-control and water-quality objectives before work begins.
Article 10 of this ordinance shall govern the design and construction or alteration of all drainage systems, natural or man-made, within the unincorporated areas of Nassau County. The following objectives are hereby established in order to protect, maintain and enhance both the immediate and the long-term health, safety, and welfare of the citizens of Nassau County, while allowing landowners reasonable use of their property: a.To reduce the risk of loss of life and property due to flooding;b.To reduce the capital expenditures associated with flood control and the installation and maintenance of storm drainage systems;c.To minimize the adverse impact of land development and related construction activities on property, environmentally sensitive areas, water and other natural resources. ... Unless exempted under Section 10.3 below, the following activities will require prior approval through the Nassau County Development Review Process: a.Alteration, restriction, or removal of existing natural drainage collection, storage and conveyance systems ...
Full Breakdown
Article 10 of the Roadway and Drainage Standards Ordinance governs the design, construction and alteration of every drainage system, natural or man-made, in the unincorporated county. 1 sets three objectives: reduce the risk of loss of life and property from flooding, reduce the public cost of flood control and storm drainage maintenance, and minimize the impact of land development and construction on property, environmentally sensitive areas and water resources. 2 requires prior approval through the county's Development Review Process before anyone alters, restricts or removes an existing natural or manmade drainage system, disrupts natural stormwater flow patterns, changes the use of land, adds or resizes a structure, or creates or replats a subdivision. 2. 8. 3. 5.
Violations & Fines
Nassau County's Engineering Services department enforces Article 10 through the permitting process itself: a project built without an approved Lot Grading Form or Grading Permit, or that departs from the approved drainage plan, will not receive its as-built certification or Certificate of Occupancy. Persistent noncompliance is referred to the county's special magistrate code enforcement process, which can impose administrative fines and place a lien on the property until the drainage work is corrected.
Frequently Asked Questions
Do I need a stormwater permit to build a house in unincorporated Nassau County?
Are single-family lots exempt from Nassau County's stormwater rules?
Who reviews drainage plans in unincorporated Nassau County?
What happens on small expansion projects with an existing drainage system?
Sources & Official References
Other rules in Nassau County
Florida rules heatmap·Compare Nassau County to another location·View the Florida environmental rules overview
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