Mossyrock Dam, and some goats

October, 2021

A few blog posts ago, I visited Mayfield Dam that holds back the flow of water on one portion of the Cowlitz River and so creates Mayfield Lake, and produces electricity via turbines in a powerhouse below the dam. Today I visted Mossyrock Dam, also on the Cowlitz River, that creates Riffe Lake.

The two dams are only about 8 miles apart, as the crow flies, but because the terrain here is steep that means the lakes are deep, so there’s lots of water available for producing electricity even though the dams are relatively close to each other. Each dam is used to create a lake such that some water from each lake is diverted around/under/through the dam, using in-dam or inground/underground passages, and then to a building below the dam that houses turbines that are powered by the falling/running water from above, and so electricity is produced … and the electricity is then sent along wires to homes and businesses in towns and cities.

So, let me show you the Mossyrock Dam. There are dams that are more famous in Washington (like Grand Coulee Dam on the Columbia River), but the Mossyrock Dam is the tallest dam in the State of Washington at 606 feet tall. The electricity produced by this one dam will light one million light bulbs for one full year. How many light bulbs do you have on right now?

Obviously, the photo above was taken of a sign in the area where I parked. The photo below is of a photo on the same sign. All dams in Washington are curved on the down-water side, so the foot of the dam is wider than the top of the dam. You can see that in any photo of any dam (like the photo above). But only some dams are curved outward on the upper lake side of the dam … the middle belt of the dam curves outward. In the photo below, the upper lake will be on the left side when the water fills in. See how that mid belt of the dam curves out into the future lake? Not all dams do that.

Here’s where I parked. Not another soul in sight. It was beautiful and very well maintained.

 

My first view of the dam … notice those four black rectangular holes.

I walked around to the right, past the dam a bit so I could see the lake side of the dam.

 

Thanks to reader Vernon Hauser, we now know that the huge extension out into the lake is the spill-way for high water situations. The top of the extension is just a few feet lower than the top of the dam. So if/when the lake water rises so high that it almost spills over the entire dam, it will actually spill over/into the extension and be a controlled spill of water. Thanks Vernon. 🙂

And then I walked back to get a look at (and a photo of) the top of the dam. Notice those four rectangular holes again. They are huge. They are about 30 feet high and 30 feet wide, each of them. I based that estimate on the fact that the roadway across the top of the dam was a two-way roadway allowing vehicles to cross in both directions at the same time.

 

 

Photo below, I walked out onto the top of the dam as far as I could go. You can see the gate that stopped me on the right in the photo below. At the bottom of the dam is the building (the powerhouse) that houses the turbines that create electricity … and the two conduits that bring raging, racing water down to turn those turbines.

But also notice up near the top of the dam there’s a small line of something … pipe? I couldn’t really tell since it was so far away. But it couldn’t have been much of anything since it seemed so small.

Well, I zoomed in with my camera … here (below) is that “small pipe”! It’s a large walkway, with a relatively large doorway for humans right in the middle. I assume that’s there so people can check the high power electrical cables that come up from the powerhouse (the ones with the small black dots on them) and then the cables that, in turn, run out to deliver electricity (the ones with the large black things on them). Ah me, so much of life I don’t know about.

In some of the photos above, you may have noticed black streaks on the dam. The dam leaks. The black streaks are the result of water from Riffe Lake, the lake behind the dam, leaking through onto the face of the dam. Or maybe the leaks are from the water pouring down through the inside of the dam to the powerhouse.

 

 

Look at the walkways on those two conduits above. I can’t begin to guess how much water pours through those conduits!

And here below is a look up Riffe Lake, the lake behind the dam. The dam is on the left but out of the picture. Riffe Lake is so beautiful.

There are 18 hydroelectric dams in the State of Washington (dams that produce electricity). Until I looked that up online, I figured there were maybe 6 or 7 such dams. I’m impressed! Especially since I read online that there are only 71 dams that produce hydroelectricity in all of the USA. The Grand Coulee dam on the Columbia River in Washington State produces the most electricity of any hydroelectric dam in the USA … producing more than double what it’s nearest competitor produces (a dam in the State of Virginia). Of the 15 highest-producing hydroelectric dams in the USA, the State of Washington has 7 of those dams.

There are problems/complaints about dams, all of them, whether they are used to produce electricity, or used to regulate water downstream, or other uses. One of the sad things about dams is that they have flooded millions of acres of land, flooding wildlife homes, and have eliminated access to native nations’ sacred land and the history and homes of native nations, many times without permission from or compensation to those people. And many dams have affected or eliminated fish habitat in what was a free-flowing river prior to the construction of the dam. In Washington, there’s a concerted, mostly successful effort to truck fish around dams so the fish continue on “up river”.

Some dams have been taken down in recent years. The largest dam ever removed in the USA was on the Elwha River here in Washington State. As solar and wind and ocean wave and radio wave production of electricity increases, dams are slowly being removed. I think that’s a good thing. And yet, dams are fascinating.

And, hey, other things are fascinating too, yes? 🙂

Like ducks! I was driving around the countryside after visiting the Mossyrock Dam. I came around a bend in one country road to find a large, beautiful, peaceful lake on my right. I slowed and meandered around the lake. Almost at the far end of the lake, I spotted this raft of ducks … all congregated out there in the middle.

I’d never seen anything like it. So I stopped and got out of the truck and walked as close as I could to the edge of the lake and zoomed in the camera for the photo below.

Ah me. Fooled again. It’s a bunch of wooden duck decoys all tied together. Ok, fine, fine, joke’s on me. 🙂

But around another corner I found real live goats and some wonderfully goofy storage buildings.

 

Ba-a-a-ah!