On the 1st and 2nd of May 2010, the City of Nashville experienced a storm event of epic proportions, defined by the National Weather Service as a 1,000-year flood. The storm caused significant damage and destruction of private and public facilities, including K.R. Harrington Water Treatment Plant (KRH WTP), one of Nashville’s two water treatment plants, which was knocked completely out of service by floodwaters from the nearby Cumberland River.
Gresham Smith’s engineers were part of a team that got KRH WTP back in operation within 30 days, a task that meant repairing and replacing nearly all of the plant’s equipment.
13.57
inches of rainfall in a 48-hour period
90
million gallons per day (mgd)
30
days until up-and-running
The Flood's Aftermath
Without KRH WTP 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. KRH WTP 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.
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 Service 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.
Defining a Path Forward
Just prior to the flood, we had been selected to design the replacement of the plant’s existing switchgear, which had outlived its anticipated life cycle. Before we could get started on the project, the flood event dramatically changed the project’s original 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In addition to switchgear replacement, Gresham Smith was also tasked with upgrading the chemical feed system to replace outdated equipment as well as provide consistency between the two treatment plants.Gallery
