May 7, 2006
NOTE BENE: I have added a new sub-section to this report which address penstocks such as we will show you here, how they are made, and why they leak. It is entitled, “A look at those leaking penstocks.” (031514)
We visited the Grandfather Falls Recreation Area and hydroelectric facilities north of Merrill in Lincoln County and found them fascinating. This was a typical "Wisconsin Central Get-Lost-Ride," which means we were not sure what we were seeing but it was most interesting, so we kept driving around until we obtained some sense of what the area was all about. Hwy 107 North out of Merrill is a good way to see it.
The first thing to do is to get an overview of the whole area so you can understand the individual photos and put them into some kind of context.
This is a north-south aerial photo of the Grandfather Falls area, courtesy of the US Geological Survey and presented by TerraServer USA. We are interested in the area bounded by the two red arrows, both sides of the water, the water showing up black in this photography. The Wisconsin River is flowing from the top (north) of the photo to the bottom (south). The top arrow points to the Grandfather Falls dam, referred to in some documents as the Upper Grandfather Falls dam. Most of the time, most of the river's water is diverted to the canal to the right, while the flow of water is carefully regulated that goes through the dam and into the riverbed on the left. You can see even with this photo that the canal is very full and placid, while the riverbed is not so full and appears to have some rapids caused by rocks on the riverbed. We'll show you all this closer in a bit.
Note that the canal terminates to the south. You can barely see what is a very large set of tubes known as penstocks that carry that water overland and through a hydroelectric plant located at the terminus of those tubes, where they meet the river again. You can make out that water is flowing into the river from that area at the point of the bottom arrow.
We are going to walk you north-to-south, from the top of that map to the bottom with our photography of the land and buildings. Let's get started.
We'll first show you a series of photos taken within the area marked by the red box, which we call the Dam Area.
This is the Wisconsin River above the dam, looking northward. Next, we will take you straight downstream to the dam, off to the left on this image, followed by the river flowing into the canal, off to the right in this image.
This is the backside of the dam.
This is the beginning of the canal. As a norm, most of the water from the river is diverted through this canal and put through two large penstocks that carry it into the hydroelectric plant and then back out and returned to the river. This plant is located about one mile downstream the river from the dam.
Let's now look at the dam side and the throughput of the river heading downstream. After that, we'll show you the canal and how the water there gets into and out of the hydro plant, and back into the Wisconsin River below.
This is the front side of the Grandfather Falls Dam. It looks like it has seven gates. This dam was built in 1938. The entire complex we're showing you is run by the Wisconsin Public Service Corporation.
On this day, only one gate was open letting river water through. Let's zoom in to see the water coming through the gate more closely.
The truth is that on this day not much water was coming through the dam; first, only one gate was open; second, we do not think the gate was open all the way. Nonetheless, we want to show you two more shots to give you a sense for the power of even this, a single "slow flow."
The point we wish to leave is that even with a slow flow, this water is powerful, which is why it is harnessed to produce electricity. Wisconsin has by far the most hydro plants (116) of the five Upper Mississippi River Basin, which includes Illinois, Iowa, Minnesota, and Missouri. That said, Missouri, with only eight plants, produces 56 per cent of the electricity produced by the five; Wisconsin is second, producing 25 percent.
In any event, you can imagine what it would be like if all the gates were open. We'd like you to visit the web site "Midwest River Inventory" to see what it looks like when the water is humming through. We understand that the gates are opened only once per year, usually in the spring. There are warning signs all over saying that when the siren sounds, it means the gates are going to open and the depth of the river and the speed of the current are going to rise rapidly and significantly.
Our photography will show you what it's like with the water at a very low level through this one mile stretch.
This is the riverbed area just a bit downstream the dam.
This is a shot downstream the Wisconsin River shot from the area of the dam. When the gates are opened, this is a heavy-duty white water area that can be very dangerous.
Let's now move back to the beginning of the canal and walk our way to the hydroelectric plant and then marry up again with the river.
This piece of land on the right side of the photo lies between the canal and the river, the river being to the right (west).
We've now moved to the other side from where we took the previous photo, to the eastern side, and are looking west. This is the canal. You can see the rock dike buildup on the other side. The Wisconsin River is beyond the tree line.
We've now moved to the southern end of the canal.
This is an interesting spot. It serves a few purposes. First, in the lower right you can see an outlet. That takes water, should it reach high levels and be too much for the plant to handle, back to the river. We will let you see that closer in a moment. Then just right of center, there is a another gate that moves the water from the canal through the two long penstocks and into the hydroelectric plant. It also serves as a floodgate, and a siren will sound should they open it fully. That would signify that quite a bit of water is going to be allowed through, which will impact its egress at the other end.
Let's now take a closer look at the outlet back to the river.
You are now looking down the outlet shown in the previous photo and if you look closely, you can see the river below in the upper left quadrant of the photo. You can also see that not much water is flowing down to the river, which means they have achieved a nice balance between what is in the canal and what they are using. Should the canal rise, then this outlet can get pretty busy with water and it would be quite a sight to see the water hit those rocks below.
These are the two large penstocks, carrying the water from the canal to the hydro plant. This is an amazing sight, largely because there is quite a lot of water leaking from them. You can see the leaks fairly well here, but let's zoom in on a few.
NOTE BENE: I have added a new sub-section to this report which address these penstocks, how they are made, and why they leak. It is entitled, “A look at those leaking penstocks.” (030314)
So, the question is, should these leaks be there or is this poor maintenance or a poor design? When the water is humming through here, it most certainly would put a lot of pressure on the penstocks' walls, so leaks are understandable, and perhaps, desirable to avoid a major explosion through the walls of the tubes. We do not know; a good item to explore further. We did take a look at the penstocks at the Niagara Falls hydroelectric plant in New York. It is obviously handling a far greater throughput of water. The penstocks there are metal and we saw no signs of leakage. Our gut says these leaks reflect inadequate maintenence-design.
The penstocks are now entering the backside of the hydroelectric plant. You can see how they are on a more steep downward grade to get the water inside moving along at a nice clip. If you look carefully, you can see another leak right about at the center of the photo.
This is the front side of the plant. The water has run out of the penstocks through a generator, creating electricity which then is wired out. The water, done with its work, then flows back into the Wisconsin River. It looks like there are four gates at the base of the plant letting the water out. The worker on duty this day told us he had one of two generators operating, producing the desired amount of electricity. Should both generators be operating at full capacity, the sirens would have sounded, the water flow out would be far greater, and the place where I was standing to take this picture would be fully submerged. When they let this thing kick into full gear, the water will rise rapidly and significantly here and the white water created would be something to see. What's amazing is that, on average, it takes only one person part-time to operate the entire plant.
This is a closer look at the outlets. The sign on the left reads: "Warning. When siren sounds water level will rise rapidly." The sign to the right says, "Water levels change rapidly due to hydro plant operations." You can see the siren on the left side of the building. So, you get the idea. On this day, he had only one of two generators operating, and it was not at full capacity, so the outflow was not significant. That said, it was coming out fast enough to create some turbulence.
You will recall from earlier discussions that this is where the canal water meets the river, the latter of which has flowed for about a mile since passing through the dam.
This is a look upstream the Wisconsin River where it meets the canal water. In the lower right, you can see some of the foam of the water coming out of the hydroelectric plant.
The water here from the hydro plant is now merging with the river and the Mighty Wisconsin flows until it hits its next dam downstream at Wausau.
American Whitewater says that the stretch of river between the dam and the hydro plant, when it has adequate water (which it did not during our visit), is a:
"Full mile of big, wide river with an amazing jumble of rocks and a few good ledges. This is a wild stretch of river which should allow many options of routes and plenty of play possibilities. There is one main ledge about 2/3 of the way down which may rate the (IV) in the description. At low-to-moderate flows, this reach may be more in the II-III range, but the continuous nature of the rapids, and pushiness (as it heads to higher water levels) should not be taken lightly."
They say average and maximum gradient is 60 ft. per mile.
The Wisconsin Public Service says the plant can produce 17.2 MW of electric power. It is classified as a generating station, as opposed to a substation or switching station. We believe she delivers her juice to the Pine Substation in Merrill.
We'd like to alert you to Mr. Schotz's web sites about Grandfather Falls. He's taken a lot of photography and done a lot of research.
Grandfather Falls and the story behind why the town of Champagne has vanished.
Grandfather Falls photos