Hall County, GA Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing section
- § 10.5.8, Stormwater Management Standards
- Water quality target
- Remove 80% of TSS from 1.2-in. storm
- Runoff reduction target
- Retain first 1 inch of rainfall on-site
- Overbank control
- Match pre-development peak, 25-yr storm
- Design reference
- Georgia Stormwater Management Manual (GSMM)
- Enforcement
- Tied to § 10.1 / § 11.2 permit penalties
Summary
New development in unincorporated Hall County must treat stormwater before it leaves the site: Sec. 10.5.8.D requires the system to remove at least 80 percent of the average annual sediment load from a 1.2-inch rainfall event once on-site runoff reduction is used to the maximum extent practicable. The Georgia Stormwater Management Manual sets the underlying design detail.
2.For development with a stormwater management plan submitted on or after December 1, 2020, the applicant shall choose (a) runoff reduction and additional water quality shall not be required. To the extent a. runoff reduction has been determined to be infeasible for all or a portion of the site using the practicability policy, then b. water quality shall apply for the remaining runoff from a 1.2 inch rainfall event and must be treated to remove at least 80 percent of the calculated average annual post-development total suspended solids (TSS) load or equivalent as defined in the GSMM.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 80).
Full Breakdown
Sec. 5, Post-Construction Stormwater Management, applies to development meeting the applicability criteria of Sec. 6, subject to the exemptions in Sec. 7, and Sec. 8 lists the numeric standards, expressly incorporating the Georgia Stormwater Management Manual (GSMM) for additional design detail. Sec. 2-inch storm to remove at least 80 percent of the calculated average annual post-development total suspended solids load. Sec. E adds stream channel protection on top of that, requiring 24-hour extended detention of the one-year, 24-hour storm, erosion prevention measures such as energy dissipation, and preservation of the natural channel.
Sec. F requires overbank flood protection, controlling the post-development peak discharge rate down to the pre-development rate for the 25-year, 24-hour storm, with attenuation required across the two- through 25-year range if the one-year control is exempted. If a site qualifies as a pollutant 'hotspot' under Sec. 6, the county can require additional stormwater system components targeted at that site's specific pollutants under Sec. 3. Every plan needs a pre-submittal meeting and an application fee under Secs. 10, and the completed system must pass a final inspection and as-built drawing review under Sec. 14 before the county signs off.
Violations & Fines
Sec. 10.5.12 requires the built system to match the approved stormwater management plan, and Sec. 10.5.17 folds any violation, whether during construction, a missed as-built submission, a missing final landscaping plan, or a failed final inspection, into the enforcement track for the underlying land-disturbance permit under Sec. 10.1 or building permit under Sec. 11.2, giving the county the same stop-work orders, notices, and penalties available for those permits.
Frequently Asked Questions
What stormwater standard applies to new development in Hall County?
Does Hall County require detention ponds to control flooding downstream?
What happens if a completed stormwater system doesn't match the approved plan?
Sources & Official References
Other rules in Hall County
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