Dam at Shenango River Lake keeps heads above water

Apr. 3—The dam at Shenango River Lake is literally keeping heads above water.

Rainfall in the region dumped 2 inches and even more in some spots which without the dam could have drowned communities and businesses downstream.

"Right now, Shenango is using only 10% of its flood storage capacity so we have plenty of room in reserve," Megan Gottlieb, water management lead engineer for the Army Corps of Engineer's Pittsburgh District, said.

Between midnight Tuesday and 5 p.m. Wednesday, 1.97 inches of rain fell at the Youngstown-Warren Regional Airport's weather station.

The National Weather Service in Moon Township, Allegheny County, recorded 2.68 inches of rain Tuesday, an April single-day record in Pittsburgh history.

Just to show how bad it is, for the fountain at Pittsburgh's famous Point State Park to be completely submerged the water has to hit 27.6 feet, Gottlieb said. The crest forecast over the next couple of days is an even 27 feet.

"We're experiencing high water in the Pittsburgh District," she said.

But Pittsburgh won't hit levels seen during the infamous downpours of Hurricane Agnes in 1972, when water at the park crested at 35.8 feet, Gottlieb said.

Dams and locks along major waterways like the Shenango, Monongahela, Allegheny and Ohio rivers prevent catastrophes in communities along the way.

Still, slews of locks on the Monongahela, Allegheny and Ohio rivers in the Pittsburgh region were closed Wednesday halting barge traffic in those area, Gottlieb said.

It's not just rainfall over the past two days that has caused problems. Heavy rain over previous days has left the ground unable to absorb more moisture, which means every drop that falls flows directly into the waterways and over the banks.

"The ground was already saturated," Gottlieb said. "We haven't had this much in our watershed since 2019."

Completed in 1965, Shenango Dam was built to control the Shenango River, which empties into the Beaver River, then the Ohio.

Before the dam's construction, office-based businesses and merchants in downtown Sharon habitually stored vital supplies on the second floor in springtime in expectation of annual flooding. Other communities, including New Castle, along the way had the same experiences.

"Can you imagine what it would be like without the dam," Bill Spring, resource manager at Shenango River Lake, said.

Like other years, water at Shenango Lake was drawn down over this past winter in preparation of spring rains.

"Then we start holding water around mid-March," Spring said.

The lake's water table now is 896.95 feet, about 2 feet above the normal pool for this time of the year. Army Corps expectations are that the water will crest around 902 feet in the upcoming days — well below its all-time record high of 909 feet set in 1989.

Currently, four of the dam's seven gates are open but to only 1 foot — out of a maximum of 7 feet — each.

This feat of engineering will earn its keep in the coming days. The AccuWeather forecasting agency is calling for another inch or two of precipitation locally on both Thursday and Friday.

To ease pressure on the lake on Thursday or Friday the Army Corps expects to keep all seven of the dam's gates open 1 foot.

"But that can change," Spring said. "It's all based on downstream conditions."