The top leaders in the Senate and Assembly want more details on the impact of the proposed closure of the Indian Point nuclear power plant by April 2021.

As backed by Gov. Andrew Cuomo, the facility in Westchester County would wind down operations over the next several years, with renewable energy as a replacement for the 2,000 megawatts generated by the plant, which is the predominate supplier for New York City and the surrounding area.

“The fact that it supplies about 25 percent of the power to the city of New York amongst other places, it shows us there’s going to have to be a real plan on how you’re going to have make up that kind of generation,” said Assembly Speaker Carl Heastie.

“We’ll see what the details are, but it’s a tremendous supply of energy for downstate New York. We’ll have to see what the substitute is for that.”

Senate Majority Leader John Flanagan was more critical, questioning why the Cuomo administration sought no input from local elected officials, who fret about the impact closure will have on jobs and the tax base in Buchanan, where the plant is located.

“I have to look at in more detail, but the notion this thing was negotiated without the input of a lot of different people, including local elected officials and Westchester County people is problematic,” Flanagan said. “We need to have good, reliable energy sources.”

It’s unclear if the closure would require a vote of the Legislature, but Flanagan indicated more discussion is needed before the plan is to take effect.

“Just on a visceral reaction it strikes me there should be more input from some of the people that are affected,” he said. “It’s going to have major ramifications.”