Lee County, AL Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing section
- Art. IV § 4-2(2)
- Plan preparer
- Licensed engineer required
- Drawing scale
- 1 inch = 100 feet minimum
- Runoff method
- Rational method (C, I, A, Q)
- Flood cross-reference
- 100-year flood zone must be flagged
- Approval authority
- County Engineer and Planning Commission
Summary
Any new subdivision in unincorporated Lee County must include an engineer-designed Storm Drainage Plan before the County Engineer will approve Construction Plans. The plan has to map every drainage way, size each drainage structure, calculate runoff, and show how the site ties into existing drainage before a plat can move forward.
(2) Storm Drainage Plan containing all of the following information:
a. Location of proposed drainage ways, streams, and ponds in the subdivision;
b. Topography at suitable contour intervals, as approved by the County Engineer, to show proposed drainage;
c. Location, size, and invert elevations of proposed drainage structures including culverts, bridges, pipes, drop inlets, and top elevations of head walls, etc., showing details on Drainage Plan, including conduit schedule;
d. Construction details of typical manholes, connections, and other drainage structures proposed;
e. Area of land contributing run-off to each drainage structure along with run-off calculations and applicable coefficients depending on method used [i.e. Rational method: runoff coefficient (C), rainfall intensity (I), catchment area (A), and the discharge at the structure (Q)].
f. Location of easements and rights-of-way for drainage ways and maintenance access thereof;
g. Typical cross-sections of each drainage way;
h. Direction of water flow throughout subdivision and compatibility with existing drainage.
Official source re-checked September 7, 2026: the cited page had not changed since it was quoted.
Full Breakdown
Section 4-2 of the Lee County Subdivision and Land Development Regulations requires every developer filing a Proposed Plat for land in unincorporated Lee County to submit Construction Plans, including a Storm Drainage Plan, alongside the plat application under Section 3-3. The plans must be drawn to a scale of no less than one inch equals one hundred feet and prepared by a licensed engineer, the same standard applied to the required street, sanitary sewer and water plans filed with it.
The Storm Drainage Plan itself, spelled out in eight lettered items under Section 4-2(2), must locate every drainage way, stream and pond in the subdivision; show topography at contour intervals the County Engineer approves; give the location, size and invert elevations of every culvert, bridge, pipe, drop inlet and headwall, with a conduit schedule; detail manhole and connection construction; calculate the runoff reaching each drainage structure, naming the Rational method's runoff coefficient (C), rainfall intensity (I), catchment area (A) and discharge (Q) where that method is used; map easements and rights-of-way for drainage ways and their maintenance access; cross-section each drainage way; and show the direction of water flow and its compatibility with existing drainage.
The same Article IV application also requires the plat to flag any land within the 100-year flood projection under the County Flood Damage Prevention Ordinance and, where a lot extends into an approximate A Zone, AE Zone or the 100-year flood zone, to attach a Special Flood Hazard Area Development Permit before the Lee County Commission will certify the plat. The County Engineer reviews and signs off on the drainage design before construction proceeds.
Violations & Fines
The County Engineer withholds Construction Plan approval, and the Lee County Planning Commission and County Commission withhold their Certificates of Approval on the plat, until the Storm Drainage Plan satisfies every Section 4-2(2) item. A plat covering a lot touching an A Zone, AE Zone or the 100-year flood zone cannot be certified or recorded without the required Special Flood Hazard Area Development Permit.
Frequently Asked Questions
Does Lee County require a stormwater plan for new subdivisions?
What must the Storm Drainage Plan show?
Does this rule apply inside Auburn or Opelika?
What happens if a lot sits in a flood zone?
Sources & Official References
Other rules in Lee County
Compare Lee County to another location·View the Alabama environmental rules overview
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