Take out every dam??

As I mentioned a while ago, there a presentation at a Fisheries Meeting (AFS) about why removal of a specific dam on the Carmel River in CA might not be the best idea.

The particular dam, high in the watershed, is the last dam left in the system and blocks some habitat. So, apparently, NOAA is pushing for removal.

Fortunately, the system is data rich for flow info. IF the dam comes out, the fish will have access to blocked area. The cost will be the loss of 25 miles of mainstem habitat as the river will go dry most summers in the middle and lower reaches. You'll have 7 miles of headwaters instead of 25 miles of mainstem. You'll also release the brown trout from above the dam into the whole lower watershed as they are not there now.

He also described how the area is going to a desalinization plant that will make domestic water the most expensive in the world by a factor of two. Once that plant goes online, many of the current residents will be priced out of water.

Was in interesting presentation.

Dam removal should be based on a case by case review. Kinda' the way dam development should have been done, instead of assuming that every dam was a good dam.

That's what I would have thought. There is actually a proposal for this dam to dredge it out (increasing storage), raising it some (increasing storage) and finish the fish passage (in place some). The increased storage capacity would either insure that current flows could be maintained or possibly increased some.

It will be interesting to see how it plays out.

With some of the rim dams around the CA Central Valley, access to headwaters is critical and essential. Water temps in the middle and lower rivers become to warm to sustain good productivity, so salmon and steelhead evolved to use those reaches only seasonally. Much depends on the water quality (T) of those dam releases as to whether the fish would be better off with or without it. Storage of cool water is likely to become even more important if CA is to sustain native salmon and steelhead into the future.

Sg

I'm kind of a minimalist for human intervention or a nature knows best kind of guy.

Lots of coastal CA streams and rivers go dry in their lower stretches during the summer while the upper sections retain some cool water flows. Fish are adapted to this flow regimen. The Eel river is a good example of a pretty large river that is inhospitable to fish in the summer in its lower reach, but still produces a good number of winter steel.

Resident rainbows can survive in these headwater refugia while steelhead come and go with the rains, but they all intermingle at a genetic level to produce the runs we see.

Interesting things to ponder for sure & thanks for the meeting update, Carcassman.

The devil, as they say, is in the details of each situation. The presenter made the point that CA rain regimes are not 6 wet, 6 dry ( or, like western WA, 11.5 wet, .5 dry ). They are maybe 3 or 4 months wet. Especially as one goes south.

As eugene1 notes, the coastal CA mykiss are well adapted to the drought cycle. Some streams, apparently, were resident for 40 or 50 years until the flows returned. Maybe even longer.

This particular watershed, and dam, might be removable if t was depopulated of humans. This is because there are 500 "riparian" water rights there. Those rights are close to untouchable. They don't require and HCP, ESA has not been able to touch them, and they dry up streams.

Final thought, if the analysis of lost flowing stream is accurate, is that taking the dam out would be a "take" under ESA as it would eliminate habitat occupied by a listed species.

As I thought about it more, always a risky venture, I think taking out that dam might be a good thing. I believe that we should protect and restore the ecosystem. Let nature decide what lives there. In this case, especially since mykiss are optionally migratory, let them be resident until the rains return or we control all the water use humans now take.

Like up here in WA, we pass anadromous fish above a waterfall because 1) Salmon are much more important than resident fish, 2) development of the lowland area habitat is more important than the salmon, 3) we like to play with the world.

O. mykiss are without a doubt the most opportunistic and adaptable species of the Pacific salmon. They are happy maturing to 4" residents in a small stream (but they hedge their reproductive bet by kicking out some number of smolts), or they can be a mostly anadromous population if conditions permit. They live in a freshwater stream for less than a year and go to the salt, in a river or pond seemingly forever, or some combination.

People are for sure against their survival in many places, but still they endure.

Long live O. mykiss!

Mykiss are neat but clarki are better.

I will be chasing some (formerly) Oregon redbands down in Costa Rica in a couple of weeks. Top of the line pretty fish.