Iredell County, NC Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing section
- Code of Ordinances § 10.12.1
- Design standard
- NCDOT Highway Surface Drainage Handbook
- Min. drainage course slope
- 1 ft fall per 200 ft
- Curb/gutter trigger
- Subdivisions over 30 lots
- Protected waters
- Lake Norman, Lookout Shoals Lake, Catawba River
Summary
Any new subdivision in unincorporated Iredell County must include a stormwater drainage plan built to NCDOT drainage standards before the preliminary plat is approved. The rule bars discharge into sanitary sewers and sets minimum grades and side slopes for drainage courses, with a flat ban on run-off flowing directly into Lake Norman, Lookout Shoals Lake or the Catawba River.
The stormwater drainage plan shall be designed to meet the following objectives:1.The subdivider shall provide a stormwater drainage system constructed to the standards of the NCDOT... 5.Surface drainage courses shall have side slopes of at least three (3) feet of horizontal distance for each one (1) foot of vertical distance... 6.The minimum grade along the bottom of a surface drainage course shall be a vertical fall of at least one (1) foot in each two hundred (200) feet of horizontal distance... C.Curb and gutter development shall only be permitted when fifty (50) percent or more of the stormwater run-off is discharged into an on-site perennial or annual stream as determined by the most recent version of the U.S.G.S. topographic maps. No run-off may directly discharge into Lake Norman, Lookout Shoals Lake, or the Catawba River.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 32).
Full Breakdown
1 requires the developer or agent to submit a stormwater drainage plan, prepared by a design professional and showing existing topography and natural drainage, along with the preliminary subdivision plat. S. 12, Ch. 113A, Art. C. Dam Safety Law with proof filed before final plat approval; and special flood hazard areas must have adequate drainage to reduce flood exposure. 1(B) lets the Subdivision Administrator, on the Technical Review Committee's recommendation, require curb and gutter when a subdivision exceeds thirty lots, when steep topography creates a public-benefit need, or when an adjoining subdivision already has curb and gutter.
1(C) restricts curb-and-gutter development to sites where at least half the run-off discharges into an on-site perennial or annual stream (per current USGS topographic maps) and expressly forbids any direct discharge into Lake Norman, Lookout Shoals Lake, or the Catawba River, protecting the county's two reservoirs and the river that feeds them. 13.
Violations & Fines
Failure to submit an approved stormwater drainage plan blocks preliminary plat approval, and the Subdivision Administrator can withhold final plat approval until the drainage system, curb-and-gutter conditions, and the Lake Norman/Lookout Shoals/Catawba discharge ban are met. Non-compliant developers must redesign at their own cost before recording, and the county's general Code penalty under Sec. 1-7 (fine up to $50 or up to 30 days, or a $100 civil penalty) applies to violations of the underlying subdivision ordinance.
Frequently Asked Questions
Does Iredell County require a stormwater plan for new subdivisions?
Can stormwater run-off go straight into Lake Norman?
When can the county require curb and gutter in a subdivision?
Sources & Official References
Other rules in Iredell County
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