Sustaining Atlanta: City of Atlanta Watershed Management Project by Willmer Engineering

The City of Atlanta Department of Watershed Management will increase their emergency water supply by converting the former 450 feet deep construction materials rock quarry to a 3 billion gallon raw water conveyance and storage reservoir, which will increase emergency water supply from several days to 30 days.

A complete pumping facility will be developed at the quarry rim with a deep shaft to the quarry bottom. A mile long tunnel will be extend from the quarry floor to the existing Hemphill Treatment Plant where a new pumping station will pump the water from the tunnel to surface treatment facilities.

Existing raw water lines extending from the Chattahoochee River to the Hemphill Plant will be replaced by another deep tunnel, with water pumped to the surface through a shaft to the treatment facility.

Willmer Engineering performed a deep rock boring exploration program with extensive packer testing, rock classification, weathering index and strength testing to characterize the massive rock within and surrounding the quarry. Data was evaluated for input into a MODFLOW™ model to assess the potential water exfiltration out of the reservoir and the potential impacts to the surrounding areas.

Willmer also performed extensive field mapping and analyses of the rock for computer modeling and evaluation of potential quarry wall slope instability and provided recommendations for creating adequate stability during construction and operations.

During construction, Willmer provided the contractor with concrete and grout sampling and strength testing for shafts and the tunnel lining and rock bolting. Willmer was also contracted for construction materials testing for site grading and inspections for soil nail retaining walls, as well as Special Inspections for building foundations, reinforced concrete and structural steel.


Atlanta, Georgia


Dams & Reservoirs
Environmental Risk Assessment
Water / Wastewater Facilities


Geotechnical Engineering
Special Inspections
Construction Materials Testing



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