Changing weather patterns are forcing new precautions at Atlanta-area job sites. Intense rainfall, shifting floodplain boundaries and sudden flash floods require that architects, engineers, construction managers and crews all rethink certain aspects of the job—from site preparation to building design to material selection to onsite storage of supplies.
Evolving Risk: Not Just Flood Zones
Traditionally, flood planning has been based on FEMA-designated flood zones. In these areas, buildings must comply with elevation requirements and flood insurance is mandatory, according to Chris Greene, a Georgia flood insurance consultant.
Locally, Atlanta enforces this through stringent regulations; any construction in a floodplain needs permits and must meet minimum opening and elevation standards.
But recent trends show that Atlanta is experiencing not just regular flooding, but also a higher frequency of unpredictable flash flooding. Based on weather data from the National Oceanic and Atmospheric Administration (NOAA), the Fifth National Climate Assessment from Climate Central indicates that the heaviest rainfall events drop 37% more water across the Southeast than they did 60 years ago. Between 1970 and 2024, Atlanta experienced a 13.2% rise in hourly rainfall intensity – significantly increasing the risk of flash flooding, according to reporting by Axios.
The bottom line is that construction projects must now consider not only the added regulations of building in mapped flood zones but also the threat of flash floods throughout Metro Atlanta.
Design and engineering: Atlanta mandates that new developments manage the first inch of rainfall using green infrastructure like bioswales and permeable pavement. These techniques slow storm runoff and reduce peak flows—a critical part of preventing flash floods.
Further, roads, slopes and site patterns must be engineered based on updated rainfall models. Understanding watershed behavior—or using geotechnical data for slope stability—is essential in a region where hydrological patterns are shifting.
Materials Selection: Extreme heat and heavy rains affect curing and structural integrity of concrete and masonry. Concrete joints can crack under thermal stress, while intense moisture can disrupt curing. The blog of Atlanta-based Rainwater Construction Co. notes the need for admixtures, controlled curing techniques and weather-resistant mixes to prevent these issues.
For other materials, it suggests opting for higher-end marine-grade plywood, galvanized steel components and high-impact roofing systems—all of which are designed to outperform standard materials when exposed to high winds and flooding.
Finally, in the 178-page publication Protecting Building Utility Systems from Flood Damage, the Federal Emergency Management Agency (FEMA) provides extensive recommendations for elevating or flood‐proofing HVAC, electrical, plumbing and fuel systems.
On-site material storage: Sand, lumber, aggregates and fasteners should be stored on pallets, racks or gravel beds that are raised at least 12 inches to reduce flood damage and erosion. Tarps and plastic sheeting offer temporary protection during storms.
Storage areas should be located in zones that have sturdy retention berms and nearby catch basins to not only protect materials but also to prevent loose debris from washing into storm drains.
When wet weather is predicted, jobsite protocols should include advance sandbagging and securing or relocating equipment.
Scheduling and safety: Atlanta summers bring both intense heat and brief deluges. These conditions demand flexible work schedules, frequent rest breaks, shaded recovery zones and hydration protocols. (See related post: Safety and Heat-Related Illness: Strategies for Contractors.)
In case of flash flooding, emergency kits with waterproof containers, radios and flashlights should be located on-site. All personnel should be able to access these supplies quickly, and receive training on evacuation routes and what to do in the case of a flash flood.
Best Supply’s experts can help you select the right materials for Atlanta’s warm humid climate, and the gear you need to protect those materials and the workers who use them. Request a quote here.
