Watch My Dam Money

Reading the QHW 12/7 article on "Going Hydro" finally prompted me to dig into this for more than several reasons There is a lot of talk but very little proof that this will work. I hear and read lots of "I Think".

Let me tell you of what "I Think". Some of this is going to be cut and paste for two reasons: One, no since re-typing it, and Two, I'm lazy.

First to explain how hydro power works:

Flow and Head
The first step in assessing the feasibility of any hydroelectric system is to determine the amount of power that you can obtain from the stream at the site. The power available at any instant is primarily a product of the flow volume and "head." Flow volume is typically measured in cubic feet per second (cfs) or gallons per minute (gpm). Higher flow means more available power.

Head is a measure of the pressure of falling water, and is a function of the vertical distance that water drops and the characteristics of the channel, or pipe, through which it flows. Higher head means more available power. The higher the head the better, because less water is needed to produce a given amount of power. If less water is needed, then smaller, more efficient, and less costly turbines and piping can be used.

Hydroelectric sites are broadly categorized as low or high head sites. "Low head" typically refers to a change in elevation of less than 10 feet (3 meters). A vertical drop of less than 2 feet (0.61 meters) will probably make a hydroelectric system unfeasible. A high flow rate can compensate for low head, but a larger and more costly turbine will be necessary. It may be difficult to find a turbine that will operate efficiently under very low head and low flow.

In simpler terms, it converts the gravity of water falling into power.

Now a little research on Lock and Dam 21 tells us that:

Lock dimensions are 110-feet wide by 600-feet long with additional provisions for

an auxiliary lock. Normal upper pool elevation is 470.0, approximately 16 feet

above the tail waters of the dam at low water. When both pools are at their

normal depths, the difference in elevation is reduced to 11 feet or less

The maximum lift is 10.5 feet with an average lift of 6.55 feet.

The movable dam has 10 submersible, elliptical Tainter gates (20-feet high and

64-feet long) and three submersible roller gates (20-feet high and 100-feet long).

The dam system also includes two earth and sand-filled transitional dikes, and a

submersible earth dike.

What’s this mean? The maximum fall of water on a good day with the wind out of the south, normal rainfall, no spring runoff will be at best -10 feet.

Footnote on the Lock and Dam. For those of you that have seen the Missouri side of the “dam” it’s quite a disappointment. It’s nothing more that a concrete dike there and if the water reaches the top, it just runs over it. Kinda looks like the COE ran out of money and just filled in the rest of the dam with rock. Looks impressive from the Illinois side.

Now some more:

A series of 29 locks and dams on the upper Mississippi, most of which were built in the 1930s, is designed primarily to maintain a 9 ft (2.7 m) deep channel for commercial barge traffic. The lakes formed are also used for recreational boating and fishing. The dams make the river deeper and wider but do not stop it. No flood control is intended. During periods of high flow, the gates, some of which are submersible, are completely opened and the dams simply cease to function.

So. When the dams cease to function, so does our $200 million dollar hydroelectric plant. How often does this happen?

Since I wanted to see just what the fall was on a yearly basis, I copied some info from the COE web site on 2007 Lock and Dam Pool 21 and tailwater levels and imported them into a Excel.

Spreadsheet 2007 Levels

First tab/page is 2007 Pool, Second tab/page is Tailwater, Third tab/page is the “fall”/difference/head between the pool and tailwater. Falls less than 2 foot are colored in red. Falls between 2 and 5 feet are in Yellow, Falls greater than 7 are in Green.

I think that there has to be a better way to spend millions of taxpayer money on something that is more dependable that this.

I’m not a licensed engineer but this technology looks a little better for the Mighty Mississippi.

Free Flow

They currently have preliminary permits from the Federal Energy Regulatory Commission to study 59 sites on the river. Read it here.

It generates power with the flow of the river, not the fall. In times of flood when the flow increases, it would produce more power. The lock and dams on the Mississippi would be the perfect place for these. The river traffic is diverted to either end of the current dams and would not affect the barge traffic. The entire flow of the river could be channeled before the dam and go through the turbines before going through the gates.

If you could somehow incorporate these into the existing dams on the river.

Ching. Ching.

(I think)