Bill could threaten San Acacia Dam

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U. S. Senators Tom Udall and Martin Heinrich's final version of their New Mexico Drought Relief Act of 2014 surprised many regional water stakeholders when it was introduced in Congress last Thursday.

The bill will provide funding for a scientific study as well as programs addressing problems caused by the state's deepening drought.

A new provision directs the Secretary of Interior to institute "planning, permitting and modification or possible removal of the San Acacia Diversion Dam" to ensure the endangered silvery minnow can migrate up and down the river to find water in times of low flow.

"They sent it (a draft) to everybody (at the District) 30 days ahead of time without the language about removing the dam," said Socorro's Middle Rio Grande Conservancy District Director Chris Sichler. "Nobody even had a chance to comment on it. They added that two days before introducing the bill. They snuck it in at the last minute."

Environmental activist Beth Bardwell of Audubon New Mexico did not deny knowing about the provision ahead of time, but stressed the bill's goal of reaching consensus.

"Like other stakeholders, Audubon was talking with the Senator's office about language in the bill," she said. "I don't think we were treated any differently from any other stakeholder. There was language in this bill that we didn't have notice of either. I hope that people can look at this bill in the light the way it was written, to provide support for a balanced solution in the Middle Rio Grande."

According to Senator Udall's spokesperson Jennifer Talhelm, last-minute modifications to the bill were made ''primarily to address State Engineer and MRGCD concerns." Even though the provision opens the possibility of the dam's removal, she said it won't happen unless "water supplies to irrigators are not impacted." Talhelm said irrigators should voice their concerns at the public input meetings the bill requires.

District hydrologist David Gensler supports the bill's stated goal of funding projects balancing irrigators' needs with those of the minnow, but he said he thinks removing the dam will certainly harm farmers without helping the fish in any meaningful way.

The dam is really a weir, he said, a low structure that diverts water without necessarily stopping all of it. Most of the time, Socorro's irrigation supply is diverted from the river at Isleta 40 miles upstream, and channeled through the Belen Division before reaching Socorro via the Unit 7 Drain canal.

The District uses the dam at San Acacia to divert storm run off or when the northern canal system malfunctions, Gensler said.

Sichler, a farmer, relies on the dam to provide water when supply is low.

"We can't remove it," Sichler said. "That's how we get water when the upstream arroyos run. They're all below Isleta, and the only place to divert it is at San Acacia. If they took San Acacia out, we'd be up a creek."

Effects of sediment drop from upstream arroyos and flow changes caused by Elephant Butte reservoir have created flow problems that removing the dam won't solve.

"If it weren't for the gradient problem in the river, fish could pass," Gensler said.

He also disputes the notion that the dam is an impassable barrier.

"When the gates are flipped up, it ceases to exist as a dam." he said. "There's an obvious drop right below the dam, but with the rip-rap and rocks and woody debris from the last few floods, there are water paths up through the river."

Even so, he and other members of the Middle Rio Grande Endangered Species Collaborative Program have been working to figure out a better fish passage at the dam for more than a decade. They've considered fish ladders, a Archimedes screw fish pump and even a fish elevator.

"We've always said we're quite willing to entertain the idea of infrastructure (at San Acacia) as long it maintains a stable and predictable water supply for farmers down there. We can't accept anything that potentially leaves farmers hanging out to dry," he said. "I just think it's more of a political thing, not a realistic solution, because there are so many other issues going on down there."

Beth Bardwell of New Mexico Audubon Society said the San Acacia location is critical for the minnow's survival.

The San Acacia reach is prime minnow habitat because the lack of levees on the eastern shore and the distance from major dams allow the river to act more naturally, providing shelter and pools the fish need to survive the drought. She said the dam interrupts this process.

"One thing the fish does need is water. That's why looking at the diversion dam is part of the solution," she said. "The river below San Acacia is the part that dries first, and the fish are trying to move upstream, and then they hit that diversion dam."

Bardwell points out the bill calls for a plan that addresses the goals of both biologists and farmers.

"It's not dictating any outcome; it's talking about developing a plan that balances those goals, in particular when we get to San Acacia Diversion Dam — balancing the needs of irrigators with that physical impediment to Rio Grande fish habitat," she said.

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