High flows coming to Owens Gorge – what about fish and their habitat?

By Deb Murphy

The 500 cubic feet per second flows scheduled for the Owens River Gorge in late June have been postponed until later this month. But the impact of flows 10-times greater than what has been released hasn’t been postponed. What about the fish and their habitat?

According to California Fish and Wildlife biologist Steve Parmenter, the penstock between the Middle and Lower Gorge Power Plants has to be dried up for safety reasons as Los Angeles Department of Water and Power fix a mechanical problem. All this precedes the construction of a flume, scheduled for September, to begin restoring flows in the length of the gorge.

Parmenter is the go-to guy for trout in the Gorge; he’s been around since the litigation in 1991 that resulted, 24 years later, in putting water back in the once bone-dry Gorge.

“Brown trout need three things,” he said in a phone interview. “Cool, clean water, deep pools, more than three feet and gravel riffles,” providing a smorgasbord of aquatic insects. All of the above could improve with the planned flows.

That assumption isn’t theoretically. According to Parmenter, back in 2003, LADWP ramped up flows to 700 cfs in the Gorge over a period of a few days.

Once deep pools had filled in with sand, the riffles had become sand clogged. All that changed with the high flows. “The pools were scoured out,” said Parmenter. “The flows turned over the gravel and flushed out the sand.” He called the comparison between the 2003 flows and the proposed July flows as good, but not perfect.

The duration of this year’s flows is far longer, roughly two months compared to a few days. But, the mathematics of stream power indicates the proposed 500 cfs flows don’t have near the power of those in 2003, according to Parmenter.

“Big flows for months down a channel are good for habitat,” he said. “That’s not scientific, that’s anecdotal.”

So much for trout habitat, what about the trout?

“Fish do a pretty good job taking care of themselves,” Parmenter said. “The flows are high, but not out of the natural range. Fish hunker down and weather the storm.”

“With stabilized flows, the river loses its structural diversity,” he said, “holes fill in, flows across gravel riffles are slower.”

Parmenter noted the gorge has been either dry or subject to low flows for decades. There’s an obvious comparison to the Lower Owens River where efforts to restore an actual river have been stymied by controls.

Again, anecdotal evidence says the fishing experience could improve after the high flows. A few years after the 2003 release, Parmenter got a calls from anglers asking “what did you do, the fishing is great” in the Gorge.

Not everybody is convinced, however. Phillip Anaya’s concern has to do with the trout’s food source. “A big release will disrupt the hatch,” he stated in an e-mail, “washing out the hatch, limiting the food the trout eat.” Anaya and others want to see an environmental analysis done before the Gorge ramps up to 500 cfs.

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Brett
Brett
3 years ago

If Mr. Anaya wants to study the effects, why not look at the East Walker River? Every year flows drop to virtually nothing. When irrigation season starts, flows routinely climb to 500 cfs or more. Still, some of the best tailwater fishing in the country.

Philip Anaya
Philip Anaya
3 years ago
Reply to  Brett

The East Walker is a very different river than the Gorge. It is wider it has less gradient and the flows have been year to year fairly consistent and I do not know the last time there was a 500cfs flown in the Gorge. The high flows for a limited… Read more »

M Anderson
M Anderson
3 years ago

The 500 CFS flows “have been postponed until later this month” So when will the high flows actually start?

Trout Junky
Trout Junky
3 years ago
Reply to  M Anderson

when LA says they need the water..They have a ton of new homes with New Water Meters.
Let it Flow

Rick O'Brien
Rick O'Brien
3 years ago
Reply to  Trout Junky

If the City of Los Angeles would spend the money on a de-salinization plant, the Owens Valley could be green again, all the way to Ridgecrest (and beyond!)

Bob
Bob
3 years ago
Reply to  Rick O'Brien

They take the cheap water first. Please get this through your head before posting about desalination. I suggest making Eastern Sierra water more expensive if you want to see change

Rick O'Brien
Rick O'Brien
3 years ago
Reply to  Bob

And exactly HOW do you make Eastern Sierra water more expensive when the city of Angels OWNS the water already ? There will be a time in the not too far off future that the entire west coast will be covered with de-sal plants . What do you suggest we… Read more »