After years of wrangling, four states along the Delaware River won an agreement this spring with New York City officials aimed to reduce damage from flooding along the river.
Under the agreement, water levels in three city-owned reservoirs in the Catskills would be lowered during peak rain seasons to try to prevent reservoir overflows and mitigate damage in towns like Trenton, N.J. and Easton, Pa.
The one-two punch of heavy rains associated with Hurricane Irene and Tropical Storm Lee provided the first major test of the arrangement. As promised, in the days leading up to Irene, New York City officials ordered water to be let out of the reservoirs so they stood an average of 11 percent shy of full capacity.
Larry Ragonese, a spokesman for the New Jersey Department of Environmental Protection, said at first look, it seems like the measure helped. “The first hit we took from hurricane Irene and that incredible storm that came through, we did not have any real major flood issues on the Delaware,” Ragonese said.
Clarke Rupert, with the Delaware River Basin Commission, was less sure about the impact the precaution had on flooding.
“It’s too early to say,” Rupert said. “A lot more analysis would need to occur before you can make that kind of a statement.”
Two of the three New York reservoirs overflowed after Irene anyway, and there was not enough time to get levels back down before tropical storm Lee hit. With swollen rivers and an already-saturated ground, flooding has been worse the second time around. “You need to look at a lot more factors than just, ‘Well did reservoirs spill or didn’t they spill?,” Rupert said. “You have to look at soil saturation, you have to look at stream flows, and you have to look at rain and where it fell and over how long and what duration.” Rupert said with the kind of rain that has hit the Delaware Basin in the past month, it may be impossible to eliminate all flooding.