PLACER COUNTY (CBS13) — A controversial dam project has environmental activists up in arms and furious with the Nevada Irrigation District.

The district says building Centennial Dam will preserve water, but opponents say it’ll destroy the Bear River ecosystem.

“The plants, the animals, this beautiful living river is going to be gone,” said Shelly Covert, secretary for the Nevada City Rancheria Nisenan Tribe.

The Bear River runs throughout Placer and Nevada counties for 73 miles. The proposed Centennial Dam would go in about two miles from the Bear River Campgrounds and create a new reservoir.

“We face the possibility of losing 100,000 to 120,000 acre feet of water storage,” said Nick Wilcox, NID board president. “It’s like losing our main reservoir. To the extent that we are losing snowpack, we are losing the ability to provide water in the future to our customers.”

Building a dam would give the district a reservoir of water for their customers and additional recreation opportunities, according to Wilcox.

But Covert, a Nisenan tribe member, believes the dam has no place on the Bear River.

“Do you want to come recreate on top of somebody’s family graves?” she said. “If you look around, you can’t really see Nisenan culture. We don’t have big coliseums and structures that show the past. Our past is invisible. If you don’t know what you’re looking for, you can’t see it.”

She’s worried that tribal burial and burning sites will be swallowed up by the reservoir. She told CBS13 the issue is close to her heart because several of the sites have already been covered up by previously created reservoirs.

Covert has been working with Melinda Booth, Executive Director of the South Yuba River Citizen’s League.

“It’s a 19th-century solution to a 21st-century problem, building a dam!” Booth said.

In her opinion, the dam would cause major tree loss and permanent damage to fish and wildlife habitats. And she told CBS13 it’s not worth the estimated $300 million to 500 million price tag.

“This dam is not needed,” Booth said. “NID’s own studies are showing that there’s plenty of water within the current system, even with increases in population. We need innovative solutions in the face of climate change.”

Instead, she wants NID to consider alternatives like rain capture and fixing leaking ditches.

“If the alternatives do not generate real water, they’re not truly alternatives,” Wilcox said.

He believes opposition to the dam is premature and that people should wait for the environmental impact report to come out next year.

But for Covert, regardless of the findings, she would be devastated to see part of her heritage disappear.

“We believe that this river has a spirit and a life and that it deserves to flow freely,” Covert said.

On Wednesday, the NID will present their plan to the California Water Commission, hoping to receive $12 million in grant money for the dam. But SYRCL plans to continue to fight against the project and hopes to receive enough support to file their opposition with the water commission.