Damned Dams - Harps FP - Good or Bad?

[mattklara]

So, American Rivers has dubbed 2011 as the year of the river. Big dam removals on the Elwha and White Salmon.

http://www.sexyloops.com/2011.shtml?1027

A dam is gone on the Hood River, OR and another on the Sandy.

With the exception of the Elwha, all of these are within 1.5 hours drive of my home.

So, I have a vested interest.

Without question, removing a dam will have a positive impact in the long term on a rivers geomorphology, allowing natural processes to reestablish themselves.

But are the removals good for the fish?

Migration barries are gone. EXCELLENT!!!

Right?

Maybe.

For example, Marmot Dam o nthe sandy had a fish ladder and it was used to block all hatchery raised fish (bad genetics) from spawning in he upper watershed. With the barrier gone, and the hatchery programs still going strong on the river, hatchery strays are showing up on the redds in alarming numbers.

The word from my friend Mia, feet in the river, is bleak.

http://oregonsteelhead.blogspot.com/2011....on.html

The situation is such that the Native Fish Society and others have "filed a 60-Day Notice Pursuant with the intent to file suit against ODFW (Oregon Department of Fish and Wildlife) and NMFS (National Marine Fisheries Service) for the violations of the Endangered Species Act and National Environmental Policy Act in funding and operation of the Sandy River Hatchery in Sandy Oregon".

Right on, I say.

Dam removal is the first step, but proper fisheries management needs to go hand in hand.

On the Elwha, a debate is raging about whether to use hatcheries to repopulate the upper river which once hosted mega chinooks over 100 pounds. An alternative is to let nature repopulate.

On the Hood and White Salmon, the same opportunities present themselves. Hatchery clones, or natural repopulation. Wild fish stray as well and may be able to reestablish runs on their own.

What do you guys think?

[Eric]

On the Elwha, do you know if 'stray' wild fish were still entering the river mouth on occasion even with the dams in place? If so, I's say at least give them a shot at finding their way upriver before dropping in the truck fish.

Are there alternate planting methods? Something like capturing parr or wild spawned eggs that would be transported to the Elwha?

[mattklara]

There are native wild fish in the lower Elwha as far as I know. Not strays.

I think there are alternatives. The real hope is that there are resident rainbow populations up in the headwaters that still retain the steelhead urge to head downriver. It's alltogether likely.

Unfortunately, i fear that the 100 pound Chinook genetics have been lost.

[Eric]

Hey Matt,
Really nice bit about the Elwha here from Jim Kerr. Pretty clear call, don't turn it into another fish factory. Let those trapped upstream come on down and let nature have a shot. A hatchery can be added 10 years from now if it's failure, but a natural repopulation won't get another shot if we don't try it now.

[mattklara]

Good one.

Man, the White salmon is puking out the nastiest silt since the breaching of Condit Dam. The river looks like Hershey's Syrup. Alot of us are starting to wonder if they expected it to be so nasty for this long. There is a really strong chance that this could effect salmon that spawn in the mainstem Columbia River downstream of Bonneville Dam in the free flowing reach. And there is so much more sediment still in the old reservoir.

This video shows what has eroded so far and how much more there still is. What will be the lasting effect on the White Salmon and the Columbia? How long will it take to stabilize?

http://www.youtube.com/watch?v....o_title

[Harps]

(Eric's FP)

I am amazed that the dam was blown like that. Even though there was a chance that the sediment could go d/s in a big flush, the chance that it could dump toxic built up crap all season just seems too high... but I don't know the details.

I would hope that folks are stabilizing the sediments with willow cutting and wattle fences, as well as rock armour on the new meander corners where necessary. Fall rains and a spring flood could be devastating!

In terms of stocking... I say the smart thing would be to wait and see what naturalized fish do before thinking about a hatchery (bad idea). I wish we could manage people better... we think we need to manage the fish and we suck at it!

[mattklara]

I would hope that folks are stabilizing the sediments with willow cutting and wattle fences, as well as rock armour on the new meander corners where necessary. Fall rains and a spring flood could be devastating!

Paul, the sediment was basically filling the historic gorge - a bedrock canyon, meander corners and that stuff were never really an option. The geomorphoolgy was and will be dictated by bedrock and massive bounders. At this point, there is no way to stabilize that silt in many areas. The plan was to let it go out on its own. It needs to get out of the canyon somehow. We could use those flows to wash it out asap, hopefully with alot of clean water in the big river downstream to dilute it. The good thing is that there are only about 3.5 miles of river downstream of the dam, and 4 miles of reservoir site. The bad thing is that the Columbia River is accepting all that muck.

[Eric]

Hopefully it gets through in a similar manner to some natural event like a landslide, though the silt sounds finer than your standard shovel of dirt.

I thought I read something about the Sandy recovery along the line that the silt wash had some positive scouring and cleaning effects on the previously controlled flow section. Will try to find it.

[mattklara]

The Sandy has a hugely different sediment regime than the White Salmon. I dont want to talk beyond my knowledge here, but comparing the two removals is like apples and salmon.