May 31 is National Dam Safety Awareness Day. The Wisconsin Department of Natural Resources notes that this day was established to commemorate the 2,200 people who died in the 1889 South Fork Dam failure near Johnston, Pennsylvania. In the new era of extreme weather events, water retention dams are at high risk of failure.
Over two days in August 2018, four western Wisconsin counties were hammered by heavy rains that caused two dam failures and damaged five more dams. Vernon County got 10 inches of rain, destroying buildings, roads and bridges.
In neighboring Michigan, the city of Midland received 4.7 inches of rain in a 48-hour period in May 2020. Upstream, the Edenville dam failed and Midland was soon under nine feet of water, pushing homes off their foundations. The resulting floods forced 10,000 residents to evacuate and caused over $200 million in property damage.
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The U.S. Army Corps of Engineers estimates that the average age of the country’s more than 91,000 dams is approaching 60 years old. Dams are generally built to safely last about 50 years. The inherent risks of aging infrastructure and underinvestment in maintenance, combined with climate change, greatly increase the risk of dam failures.
Wisconsin has approximately 4,7000 dams; 920 are large dams made of concrete and steel. Large dams are regulated by the state or federal regulatory authority. Small dams are inspected by their owners. Many of Wisconsin’s smaller dams are made of crushed rock, clay or soil. These are called earthen dams.
The state’s budget of $752,000, including only 11 dam inspectors, is not enough to provide adequate safety for aging dams exposed to extreme weather events.
Dams holding mine waste tailings are constructed of crushed waste rock and sandy soil. These dams are 10 times more likely to fail than dams holding water. A tragic example is the January 2019 breach of the Brazilian earthen tailings dam that killed 270 people and contaminated local water supplies. Worldwide, there have been 46 tailings dam failures in the past 20 years.
The same design for storing mine waste, known as the upstream dam construction method, is being proposed for the Back Forty Project, a large metallic sulfide mine and tailings dam on the Wisconsin-Michigan border. This earthen tailings dam and mine would be just 150 feet from the Menominee River. Despite the fact that the Menominee River is an interstate waterway, the state of Michigan has assumed permitting authority because the proposed mine is located in Stephenson, Michigan. The Wisconsin DNR, under former Gov. Scott Walker, allowed Michigan to assume exclusive jurisdiction over the permitting process.
If this dam were breached it could send toxic wastes into Lake Michigan and threaten drinking water for millions in the upper Midwest. The Coalition to SAVE the Menominee River and the Menominee Indian Tribe of Wisconsin are determined to prevent this from happening. To send a letter urging Michigan’s Department of Environment, Great Lakes and Energy (EGLE) to deny the dam safety permit for the Back Forty Project, go to the coalition’s webpage: www.jointherivercoalition.org. To view a 5 minute video where I call for greater dam safety and inspections, go to: https://www.youtube.com/watch?v=M089bmle35o