Saturday, January 13, 2018

MWRD: Reducing Chicagolands' Great Lakes Water Usage

(3D Satellite of Chicago River's control lock)
MWRD Posted
Construction of the Chicago River Controlling Works and Lock on November 16, 1936.
Lake Michigan is typically 2-5 feet above the Chicago River. [USACE] (Another source specifies 1-4 feet.) The lock gates have been designed to handle situations when the river is higher than the lake. This can happen during a heavy rainstorm. (Although MWRD has been spending billions of dollars for decades on their TARP plan to reduce these events.) Another reason the river can be higher than the lake is a drought in the Great Lakes watershed. One happened in 2013. [ChicagoTonight] (I was shocked that Henderson said: "It’s 70 percent sewage. A large part of it is untreated. A lot of human sewage is in that, and what would be happening is the Great Lakes would start to be filling up with human sewage from the Chicago region. That’s a problem." That was true a century ago. But it is not true now. Even in the 1800s, "filling up" would be hyperbole. But it could reach the Water Cribs. Then, when I went back in the article and saw that Henderson is speaking for the Natural Resources Defense Council (NRDC), I was angry. He is either very ignorant or lying, neither one is good for a spokesperson. Now I can't trust anything that the NRDC says!)

There are now studies being made to separate the Great Lakes and Mississippi River Basins (i.e reverse the reversing), but it is because of Asian Carp, not because of the 2013 fear that the Great Lakes were running out of water. In fact, in 2017 Lake Ontario was experiencing record high water levels causing erosion problems and threatening to close down the St. Lawrence Seaway during the shipping season.

The MWRD installed a control lock for two reasons --- water rights and the 1930's 9-foot navigation channel project.

Water Rights

Water rights is a big deal out West. The water of the Colorado River watershed is used by so many different political entities that now it is barely a trickle when it reaches Mexico. For example Denver helped pay for the Moffat Tunnel because it not only has a hole under the Continental Divide for a railroad, it has a hole for water.
And Denver has other tunnels under the Continental Divide and dams on the west side of the divide to remove water from the Colorado River. (When I married my wife in the 1970s, who was from Denver, I was shocked to learn that the households did not have water meters. Her Mom, for one, rather generously poured that Colorado River water onto her lawn.) Southern California has built dams and aqueducts so that it can use rain and snow water from Northern California. The farmers in the Central Valley also want that water. Water usage fights in the desert west are not a big surprise. But I was surprised to learn there were, and still are, water usage fights concerning the Great Lakes.

In 1909, a Boundary Waters Treaty between the United States and Canada was written to form a commission to regulate water use with this sequence of priorities; domestic & sanitary, navigation, and power & irrigation. Since, at that time, Canada was a providence of England, the treaty was ratified by William Taft and King Edward VII. There were several rivers in dispute, but the Chicago Diversion lowering the lake level by 6 inches was one of the motivators for a commission to consider the "big picture." [Wikipedia1] Compacts were written in 1985, 2001, and 2005-2015 to detail how the states and Providences use the Great Lakes water supply. (The 2005-2015 range is an example of why I tend to ignore legal aspects of industrial history. An "agreement" was signed in 2005. A "compact" was written in 2007 to document details of usage. It became law in the US in 2008. But changes were needed to satisfy Canada before "coming fully into force" in 2015. [Wikipedia2, Wikipedia3]

As part of digging the Chicago Sanitary and Ship Canal (CS&SC), MWRD also widened and deepened the Chicago River to increase the amount of water that would flow from the lake.

Because Wisconsin sued Illinois to quit draining Lake Michigan to flush its sewage down the river, MWRD started building Wastewater Treatment Plants (WTP) after the Supreme Court agreed with Wisconsin in 1929. [Wikipedia4]

9-Foot Navigation Channel

When they built the CS&SC, it terminated at a control structure where it was about the same level as the nearby Des Plaines River. The high flow in the river did not bother the steamboats that navigated the Illinois River because they were used to going upstream against rapidly flowing water over the rapids in the river. But in the 1930s, several dams and locks were built between Lake Michigan and the Mississippi River to create a 9-foot navigation channel. One of the projects was the MWRD building a canal with embankments on both sides along the 38-foot drop of the Des Plaines River with a powerhouse and lock at the end. The chain of dams on the Illinois and Des Plaines River formed a series of pools that were at least 9 feet deep. Barge operators do not want to go upstream against a strong flow of water. They want those pools of water to be as still as possible. In fact, during high flows caused by floods, they will shut down operations.

Since the WTPs removed the need for a strong flow and since the 9-foot navigation channel project made a strong flow undesirable, the control lock was built to stop the water flow into the river.

Years later, people learned that MWRD's usage had a small impact on the water level of Lake Michigan and Lake Huron. (They are one body of water as far as elevation is concerned.) Climate has a much greater impact. I have already described that we saw record lows in 2013 and record highs in 2017, just four years later.

Chicago Tonight, 2013
Street View, 2017
I remember a few decades ago when the water levels were approaching a record high that Chicago was asked to open both sets of gates on the lock and let the water flow at the original high rate. They said no. If the lake was around record levels, that means about a five foot difference. Imagine what, say, the site seeing boats would do with five feet less clearance below the bridges and trying to dock in a fast flowing river. The bear trap dam has been removed from the water control structure, so the canal would probably now flood with the higher flow. And barge operators do not want to see a fast flowing CS&SC and Des Plaines River.

Furthermore, the EPA now understands how many toxins are in the river sediment. The Chicago Tribune built its new printing plant along the Chicago River because it planned on receiving newsprint from boats as it had at its old plant. But the EPA would not allow them to dredge the river to make room for the boats because they determined the river sediment was full of toxic material. Dredging would allow the toxins to escape into the water. Opening the lock gates to allow a strong river current might also stir up the river sediments.

Chicago no longer needs, nor wants, water to flush its river. But its water filtration plants do draw a lot of water from the lake. I leave Water Commission issues concerning water supply usage for another post.

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