dampainter
Yes, I have been in lots of dams! If you question my reply, just ask Salmon G. He's been with me on numerous visits during the entire construction fazes of the Cowlitz Falls Dam. I was the FOC legal representative for that organization when Bonneville Power made a settlement agreement with the FOC which assured that Fish Collection Facilities would be installed at the new Cowlitz Falls Dam. The original project did not require any fish collection facilities to be installed on the project.
Our settlement changed that forever and assured that the Cowlitz would once again have an opportunity for recovery of its natural spawning fish.
I was very involved in the technical meeting that defined the designed of and the implementation of the new fish collection facilities. Because of my lack of engineering background, I didn't have much to give other then my knowledge of the Cowlitz and its fish. I did learn a tremendous amount about "dams" and how they function.
I also helped put special anchors in the reservoir for our fish rearing net pen projects and walked the terrain prior to the filling of the Cowlitz Falls reservoir. That was sometime back in the mid nineties. That also gave me the opportunity to see a reservoir both before and after it had been filled.
Most people never get such an opportunity to see how silt can build up after a dam has been operating for years. The droughts of recent years afforded me the opportunity to see first hand how silt can accumulate. You wouldn't believe just how much silt has already build up in just 6 years! Even though the Cowlitz Falls reservoir is a relatively small one, it surely reflects how silt can fill in the reservoirs carrying capacity.
Once a reservoir starts filling up with silt, they begin to loose some of their head pressure and the turbines become less and less effective. It's the head pressure that makes the turbines turn, not just the amount of water that stored behind them.
A thousand miles of stored water that is only ten feet deep at the dam turbines intakes makes it just about worthless for tuning large turbines. At some point, be it 60 or 125 more years, most dams will loose their head pressure, which will make them totally inefficient to run or operate for power generation.
It's pretty well known and accepted by most of the biologists on this board, that all dams are domed at some point in time. The biggest problem is; they just don't know exactly when that time may be! Lots of different natural events control that factor, and it would almost be imposable to predict those events and their regularity.
When one considers that the average amount of sediment transported into Riffe Lake is to be 1,000,000 cubic yards a year (on the average), how much sediment has been dumped into it in the pass 35 years? Now you take a massive river system such as the Columbia, and you can do your own math! Sooner or later, they will be filled in with sediment!
You asked me "where's this silted in study of yours?" It pretty simple to find; just look at the FERC/FEIS-133 (Cowlitz River Hydroelectric Project; FERC 2016). Any dam that is currently going though a relicensing process, or is about to do one has to do a "Sediment Accumulation Study". So pick any dam you chose, and read what there own studies or EIS says. Then do the math again and add them all up and see what the pictures looks like; it's just a mater of time!
Finally, I agree with you that dams will be here for a long time; but not all of them are worth having! Some dams may be in need of being decommissioned, while others may be worth keeping! It really doesn't have be one of those "all or none choices" when it comes to removing dams.
Cowlitzfisherman
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Cowlitzfisherman
Is the taste of the bait worth the sting of the hook????