After a 29-month drought, why are York Water reservoirs almost full? An in-depth look

• Despite a 29-month drought, York Water Company reservoirs are almost full due to a carefully managed strategy of diverting and storing surface runoff.
• The company prioritizes pulling water from the South Branch of the Codorus Creek, supplementing it with stored water from reservoirs.
• While current water sources are sufficient for the next 20 years, the company can utilize the Susquehanna River as an alternative source if reservoir levels drop below 60%.
• York Water emphasizes its system is in good shape and encourages customers to be mindful of water usage despite the ample supply.

After 29 months of drought in York County, a time span that included emptying Lake Williams for a 100-year dam replacement, the York Water Company’s reservoirs are almost full. A carefully managed strategy of diverting surface runoff from multiple sources and storing it keeps the taps flowing for 80,000 connections during dry conditions. 

“Despite that we are in a historic drought, Lake Williams, Redman supply is over 92 percent. … Redman is full and Lake Williams is 2.6 feet below the spillway (on March 20),” JT Hand, president and CEO of the York Water Company, said, adding that one foot of height was added to the new dam so the current water level is actually closer to the lake’s historical spillover point.

Since January 2023, York Water has recorded a 26.5-inch precipitation deficit below the area’s average, Hand said. They have been keeping records since the 1880s. 

January 2025 “was not a good way to start the year,” Hand said, with only .87 of an inch recorded, “lowest month on record.” February added 1.44 inches and March 1.11 inches so far, adding that “if we get no more rain before the end of March it would be just about six inches below average already (for the year).”

It’s deceptive to look at the water level of the two York Water reservoirs as the entire capacity of their collection system. Their first choice is to pull water from the South Branch of the Codorus Creek at the Brillhart Pumping Station and use that in combination with the East Branch that supplies the reservoirs. 

More: Drought conditions persist in York County. Here’s what it will take to alleviate it

Recently in this drought, there has been more water available from the South Branch than the East Branch, as more precipitation has fallen on the west side of Interstate 83 in York County.

The York Water system users consume an average of 20 million gallons per day, according to Hand. On March 20, there was 22.5 million gallons flowing past the Brillhart Pumping Station each day and 10.6 million gallons flowing into the reservoirs, Hand said. 

The goal is to use as much water as possible coming down the South Branch and then supplement that with the stored water in the lakes. And that is why the level in Lake Williams is going up when the flow into it is less than the demand of York Water customers. “As long as we can pull from the South Branch, we allow the East Branch to fill up our reservoirs,” Hand said.

Both water intakes must allow a certain amount of water to keep flowing downstream as a dry stream bed would kill wildlife, so York Water can never take the full amount available flowing down either creek. Water is always bypassing a dam at each location, exiting a pipe below the dams. 

“Not a drop of water over the dam at Brillhart Station, no water goes over the dam, we capture, we pump everything,” Hand said referring to pumping everything permissible arriving from the South Branch. On the East Branch, minus the stream conservation flowing out of a pipe through the Williams dam, only when the reservoirs are full does the surplus spill over the new Lake Williams dam. 

Current water sources will satisfy growth planning 20 years in the future, Hand said, adding that they are always looking ahead to provide an adequate supply. On top of that, the system can easily accommodate a new industrial user requiring one to two million gallons per day, Hand added.

An alternative third source of water for York Water can come from the Susquehanna River through pipes that feed into Lake Redman. That was only used once, when construction of the new Lake Williams Dam required that lake to be drained and that project coincided with the current drought. The river water pumps are only put in service when the level of the reservoirs drop below 60 percent, Hand said, adding, and “we are a long, long way from that.”

Going forward, if the overall drought continues to worsen, the Department of Environmental Protection could elevate overall water restrictions regardless of the levels of York Water Company storage pools

In walking the balance between drought conditions, state mandates and water use, Hand wants customers to know that “York Water Company System is in really, really good shape. We don’t want people to see we are full reservoirs and start dumping water frivolously, (however) we want our customers to know that we have invested wisely…”