Chatham County, GA Stormwater Regulations

Chatham County operates under a Phase I Medium MS4 NPDES permit, making it the largest and most regulated coastal MS4 in Georgia. The City of Savannah drives most stormwater activity in the county. Tidal ranges exceeding 9 feet create severe drainage challenges. GA EPD penalties reach $50,000 per day for violations.

Primary source: Georgia Environmental Protection Division (EPD) Watershed Protection Branch

Permit Requirements

Chatham County's Phase I MS4 status imposes the most detailed stormwater permit requirements of any coastal Georgia county. The state NPDES Construction General Permit (GAR100002) applies to land disturbance of one acre or more. The City of Savannah and Chatham County may have local thresholds that require stormwater review for smaller projects.

Georgia's GSWCC certification requirements are strictly enforced in the Savannah metro area. Level II Certified Personnel must be present on permitted sites, and Level IB Certified Inspectors must conduct regular inspections. The volume of development in Pooler, west Chatham, and the I-16/I-95 corridor generates high demand for certified personnel.

The GA DNR Coastal Management Program Area covers all of Chatham County. Coastal Marshlands Permits are required for work affecting tidal marshes, which are extensive throughout the county. The Savannah River, its tributaries, and the interconnected tidal creek system that threads through Chatham County all fall under coastal jurisdiction.

Inspection Obligations

Construction site inspections follow the standard Georgia schedule: every seven days and within 24 hours of 0.5-inch rain events. Given Chatham County's Phase I MS4 status, both city and county inspectors actively monitor construction sites in addition to the required self-inspections.

The Phase I MS4 permit requires outfall monitoring, water quality sampling, and detailed record-keeping that Phase II communities don't face. The City of Savannah's stormwater management department conducts systematic monitoring of the storm sewer system, including dry-weather screening for illicit discharges.

Post-construction BMPs must be inspected annually by the responsible party. The City of Savannah maintains an extensive inventory of permitted stormwater facilities and conducts compliance inspections. HOAs, commercial property owners, and institutional facilities are all subject to BMP maintenance inspections.

Penalty Structure

GA EPD can impose civil penalties up to $50,000 per day per violation under the Georgia Water Quality Control Act. The higher enforcement activity in Chatham County, driven by the Phase I MS4 permit and development volume, means violations receive more attention than in rural coastal counties.

The City of Savannah enforces its stormwater ordinance aggressively, with dedicated enforcement staff who issue notices of violation, stop-work orders, and fines. The city can revoke land disturbance permits, withhold certificates of occupancy, and require corrective action plans for non-compliant sites.

Chatham County's unincorporated areas fall under county enforcement. The county engineering department reviews development plans and inspects construction sites. GA DNR's Coastal Resources Division handles violations of the Marshlands Protection Act and Shore Protection Act within the coastal zone.

Key BMPs

Chatham County's extreme tidal range, flat topography, and high water table make BMP design particularly challenging:

• Wet detention ponds with tide gates - Standard for larger developments. Must account for 7-9 foot tidal range at outfall structures. Tide gates prevent tidal backflow from flooding pond systems.
• Pump station-assisted drainage - Required in low-lying areas where gravity drainage isn't feasible during high tide. Common in historic Savannah and barrier island communities.
• Bioretention with underdrains - Necessary due to high water tables. Standard infiltration designs fail in Chatham County's saturated soils.
• Constructed wetlands - Complement the natural tidal marsh environment. Provide excellent water quality treatment when designed for coastal conditions.
• Permeable pavement - Used in commercial areas and parking lots, particularly in Pooler and west Chatham. Must account for high groundwater conditions.

Local Ordinances

The City of Savannah's stormwater management ordinance is the most detailed in coastal Georgia, reflecting the requirements of the Phase I MS4 permit. The ordinance covers all aspects of stormwater management, from construction-phase erosion control to post-construction BMP maintenance, illicit discharge prohibition, and industrial facility inspection.

The City of Savannah operates a stormwater utility funded by fees assessed on developed properties. Revenue supports drainage infrastructure maintenance, flood control projects, water quality monitoring, and regulatory compliance activities. The utility has invested heavily in pump stations, tide gates, and drainage system improvements to combat chronic tidal flooding.

Pooler has emerged as one of the fastest-growing cities in Georgia, generating significant stormwater permitting activity. The city's development standards require stormwater management for new commercial and residential projects, coordinated with Chatham County's MS4 program.