New Jersey American Water Response to Tropical Depression Ida: Raritan-Millstone Flood Protection Project Passes Test

Sep 23, 2021

In the aftermath of Topical Depression Ida, New Jersey American Water, the state’s largest water and wastewater utility company, reports that all its operating areas successfully withstood widespread flooding and drinking water quality was not impacted in any of its service areas.

New Jersey American Water successfully implemented flood protection plans at all its treatment plants and other facilities, adjusted treatment processes as needed to continue to meet water quality standards despite challenging source water conditions, and maintained operations of all plants under regular or alternative power sources throughout the storm.

This includes the Raritan-Millstone Water Treatment Plant, which was fortified with a $37 million flood protection project in 2018 to withstand floods that are categorized to occur on a 500-year frequency. Situated in Bridgewater, Somerset County, N.J., the Raritan-Millstone plant is New Jersey American Water’s largest water production facility and a regional source of potable water supply for approximately 1 million people in parts of seven counties in central New Jersey. The plant is located near the confluence of the Raritan and Millstone Rivers – an area of Somerset County that experiences severe flooding during significant storm events due to the relative low ground surface elevations in the floodways adjacent to the two rivers.

“If this storm had happened prior to 2018, we would be telling a different story today. The investments we made into protecting this critical facility has proven to be invaluable by holding up against this historic flood and enabling us to continue to provide water service to the 1 million customers who get their drinking water from this plant,” said Mark McDonough, President, New Jersey American Water.

Prior to the $37 million flood protection investment project, the earthen berms and north side reinforced concrete flood wall surrounding the plant were previously designed to provide flood protection for a 100-year flood event, which is marked by an elevation of 44 feet. This level was tested several times, particularly during Hurricane Irene, during which the flood waters came within one inch of the top of the wall.

With the completion of the 2018 project, the entire floodwall system at the plant was raised by four feet to an elevation of 48 feet, which is the level of flood resiliency supported by the U.S. Environmental Protection Agency and the Army Corp of Engineers, which provides flood protection from storm events up to 500-year recurring frequency. During Tropical Depression Ida, the Raritan River crested at a record 44.87 feet at its peak on Sept. 2.

McDonough continued, “Along with the needed infrastructure to maintain operations in an emergency, it is essential to have a dedicated team of experts and we are very fortunate to have that as well. As we executed our emergency response plans, which included closing and sealing our flood gates, our licensed operators, plant managers and other critical staff remained at the plant for more than 48 hours until the flood water receded, and we could safely open the gates and replace them with another shift of qualified experts. Their courage and tireless dedication are to be commended.”

In the days preceding the storm, the company executed its emergency response plans, which included stocking up on supplies, fuel, food and other provisions to enable critical workers to remain at its water and wastewater treatment facilities for several days if needed. At the Raritan-Millstone facility, workers planning to stay once the flood gates came down were not able to get back to the plant in time, as the water rose much faster than anticipated and the gates needed to be shut early, leaving the current shift of workers in place unexpectedly for 48 hours.

But due to sound preparation and guidance from experienced staff both within and outside of the plant, the team prevailed until the flood waters receded and the gates could be opened to allow for them to leave and another shift of staff to enter the facility.

New Jersey American Water invests more than $350 million annually to upgrade and renew water and wastewater treatment plants, pipes, pumping stations and other essential facilities, including an increased focus on incorporating climate variability into the company’s asset investment strategy. New Jersey American Water works to protect the viability, integrity and resiliency of water supplies and water and wastewater infrastructure in its service areas that are vulnerable to droughts, floods and extreme weather events.

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New Jersey American Water

Denise Venuti Free

Director of Communications

1 Water Street

NJ 08102 Camden

United States


+1 856 449 7357



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