I have heard that the removal of dams would result in years and years of serious silt problems and it doesn't sound so far fetched to me. I would be especially interested in what Salmo knows about this as he seems to keep abreast of such knowledge. Personally I think it certainly has the potential to be an unintended consequence.

Yes Wit there is silt in the backwaters of dams. There is also gravel and even larger forms of debris that one normaly associates with river valleys.
Undoubtdly the fines from these deposits will migrate at a faster rate than the largest and a great deal will depend on the frequency and size of the natural occuring floods that will cause this migration of gravel that has been stopped in the rivers that have dams.
Part of the cost in removal estimates deals with control of or planning for dealing with the possibility of containment of excessive siltation
Maybe you should look at it akin to a surgical procedeure when thy cut into you they cut up a bit of good stuff and get rid of the bad and leave you in pretty poor condition for awhile. But the end result is (usually) the patient is saved to resume a healthy life once again.
In the case of the Elwha it is so gravel poor that the only place you will find spawning fish is in little braids that recently opened and the gravel that is available has not been carried away the main river bed established for years is virtually void of gravel and needs some recruitment from behind those walls.

The Elwha's four miles below the dam is akin to the head of a pin when it comes to the spawning habitat above the illegally built dam. Removal will increase the production of that river beyond our wildest fears for the lower tidbit we call the lower Elwha.

I only wish there was so much concern for the welfare of the river and it's species when these Damns were built in the first place! Too late now, but to stay on topic our pacific northwest rivers systain cycles of catastrophic siltation from the young volcanic geography (ie: St.Helens). Certainly where there is sufficient habitat above the dams (the reason to remove them in the first place) then the resilient salmonids will survive siltation below, and without much doubt they will thrive in the extended habitat that is much more suited to reproduction of the species naturally.

The matter is just far more important the the interests of the few landowners who are concerned that the dock on their lake is going to be high and dry, and the walk to the river that replaces the still water will be too far from the cottage. The treasure of 100 pound wild chinook in the Elwha, now extint, is no man's private wealth but it is a treasure for the northwest, the world, the cosmos.

.02

Juro
http://www.flyfishingforum.com

Ok, I have one thing to say/add to this subject. Lake Aldwell, above the lower dam, there is so much silt backed up behind that dam, that when a family friend, in charge of surveying the depth of the lake, was able to do most of it in CHEST WADERS outside of the boat. Due to the way all of the silt, sand and gravel swings around to the side, even all the way to Ediz hook, the lower elwha tribe has LOTS to gain from the removal... Like, an estimated 3/4 acre out beachfront property increase, on top of being able to still net the river, while it is totally punched out for a few years, and having opportunity of catching 100% of all returning fish?! Sure the tribe's gonna support it...

Tom

So Tom maybe its none of my bussiness but I was wondering if you think that its a bad idea to remove both the dams simultaneously so as to reduce the time frame on the silt trapping and runout phase.

There was a fairly substantial engineering study done on the lower dam by the USGS concerning how to manage the breaching to avoid damage to the lower river from sediment. It would be lowered in stages, if I remember correctly. There was also a biological study of the current fish distribution above both dams, so there will be "before" and "after" data on the fish community. Pretty obvious there will be anadramous fish then that there are not now, but the effect on resident fish, e.g. bull trout, is an issue as well. If I remember, Gorton's original position was to take out the lower dam first and see what that does to spawning; trouble is, there is little or no quality spawning habitat in the reach between the dams--an approach fated to show failure. Both need to come out.

Wit,

Yes, there's a lot of fine sediment behind the Elwha dams. The NPS will attempt to stabilize some of it. I read that the vast majority is estimated to be carried to the Strait in the first two years following dam removal. That's if they remove both at the same time. Figure longer if they do it Gorton's way.

And mind you, the sediment issue only applies to the lower Elwha. It's the upper river that will be producing most of the fish just as soon as they have access to it.

Heavy sediment loads are normal to northwest rivers. The best illustration I know of is the South Fork Toutle after St. Helens blew in 1980, depositing a larger sediment load than any dam. The river was closed to fishing for a while after that. By 1986, the South Fork had its largest steelhead returns in recent history. I'm not recommending dams or volcanos as being good for fish, but the sediment issue is vastly less serious to fish restoration than leaving the dams in place, which precludes restoration.

Ya' got to break eggs to make an omelette.

Sincerely,

Salmo g.

The upper Elwha will produce zero fish after the dam(s) removel and will only produce fish if and when they build a hatchery and getting the funding to build the hatchery could be very hard to do. The lower Elwha has been void of native fish for many many years.

juro, I don't think there are any private docks on either lake. It's been a while since I fished them, but i don't remember any. I think there is just a couple of people with lake views that don't want river views. Some may think that the dried up lake bed may be ugly, but when they lowered lake Mills for the geological survey, it only took one summer to have too much vegitation to walk through.
Last cast, I think you could bring fish in from other hatcheries, and I guess I must release several unmarked hatchery steelhead every year. There also must be a few salmon that missed the hatchery last weekend when I was up at the dam.
Native son is correct, a large part of the cost of removing the dams is trucking the silt away. I know my employer is looking forward to leasing any available trucks, and said anyone with a dump and pup could get quite a bit of work from it.

There are still native fish in the Elwha but they are very few in number.
Checking on river flows this evening I clicked on Elwha and came across a press release dealing with this topic by the USGS. So if you want a little more info on silt behind the Elwha dams look up http://wa.water.usgs.gov/reports/news/news.wrir99-4215.html
The report is brief so be brave and indulge.

Native Son,

I have to say, In many ways I am for taking the dams out, and others I'm not.. Things need to be worked out on both state, and tribal agreements.. I'm not for taking the dams out, IF the tribal administration is not willing to put somewhat an end to the gillnetting on the river. Whats the point in trying to restore something, if sacrifices are not made on both sides? And Yes, I'm implying shut it down for sport fishing as well! It's just like the chinook run, I have no problem with it being closed off to sport fishing, simply because a vast majority of the tribe seems to leave them alone. At least net wise... I know that there are still the few that go down and snag a few, but then, I also know that there are quite a few sportsmen (so called) that do the exact same thing... If they are both pulled out, I'm not too educated on the whole removal of both vs. one at a time, but it would seem better to me, for both to be gradually lowered at the same time.. And distribute the silt evenly...

Tom