DeKalb County Department of Watershed Management


DeKalb County, GA


Water Engineering, Environmental Engineering, Structural Engineering, MEP Engineering

On May 1st and 2nd, 2010, Nashville experienced a storm event of epic proportions, classified as a 1,000-year flood by the National Weather Service. The storm caused significant damage and destruction of both private and public facilities, including K.R. Harrington Water Treatment Plant (KRH WTP), one of Nashville’s two water treatment plants. The facility was rendered inoperable due to floodwaters from the nearby Cumberland River. Gresham Smith’s engineers played a crucial role in a collaborative effort to restore the plant to functionality within a remarkable 30-day timeframe—a challenging task that involved repairing and replacing almost all of the plant’s equipment.

inches of rainfall in a 48-hour period
million gallons per day
days until up and running
K.R. Harrington Water Treatment Plant overcome by floodwaters.

The Flood’s Aftermath

Without the plant in service, water storage capacity fell to a dangerously low 37% percent, and the entire metro area was dependent on Nashville’s second plant—Omohundro Water Treatment Plant—for potable drinking and fire protection water. K.R. Harrington had sustained significant damage to major equipment such as the electrical switchgear, electrical motor control centers, breaker panels, high service pumps, backwash water pumps, numerous electrically actuated valves, instrumentation and controls, chemical feed systems and the clearwells.

Workers with hard hats prepare to test equipment at K.R. Harrington Water Treatment Plant.

Compliant Recovery

Gresham Smith and teaming partner CH2M tracked daily progress of the on-site contractors, developed start up plans, and established protocols for testing of each piece of the treatment process to remain in full compliance with all state and federal regulations. Thanks to the around-the-clock efforts of Metro Water Services and City employees, our engineering team and partners, all water restrictions were lifted less than 30 days after the historic flood and before the city’s water supply was exhausted.

Side view of new electrical building at K.R. Harrington Water Treatment Plant.

Defining a Path Forward

Shortly before the flood occurred, we were chosen to design the replacement of the plant’s existing switchgear, which had outlived its anticipated life cycle. However, the flood significantly altered the project’s initial purpose and scope to include recovery. In addition to switchgear replacement, Gresham Smith was also tasked with upgrading the chemical feed system to replace outdated equipment as well as provide consistency between the two treatment plants.