Michigan: Risks & Trends

Same standard as every other page on this site: every figure below is independently sourced, and figures that vary across sources, or measure genuinely different things, are flagged as such rather than collapsed into one number that looks more precise than the underlying data actually supports.

The Flint water crisis (2014-2015): a municipal water system as the hazard

Metric	Figure
Water source switched to Flint River	April 25, 2014
Switched back to Detroit water	October 16, 2015
Total residents exposed to elevated lead	~100,000
Children exposed to high lead levels	6,000-12,000
Legionnaires' disease cases, Genesee County	87, June 2014-November 2015
Legionnaires' disease deaths	12 confirmed (some later counts include 2 additional deaths, for 14 total)
State of emergency declared	December 15, 2015 (city); January 5, 2016 (state); January 16, 2016 (federal)

Why the death-toll figure varies slightly, and why that's not a red flag

The 12-death figure is the most commonly cited confirmed Legionnaires’ toll tied directly to the water switch; some later accounts include 2 additional deaths bringing the total to 14. This is the same kind of death-count evolution this site has flagged for other disasters (Winter Storm Uri, the 2021 Oregon heat dome), not a sign of unreliable reporting, just how mortality investigations for a slow-developing public health crisis typically resolve over time.

The crisis wasn’t caused by a natural event at all: switching the water source to save money, without adding required corrosion-control treatment, let the more corrosive river water leach lead directly from aging pipes into tens of thousands of homes for a year and a half before the switch was reversed.

The Edenville and Sanford dam failures (2020): aging infrastructure, sudden failure

Metric	Figure
Date	May 19, 2020
Rainfall, Midland County (3 days prior)	4.7 in
Rainfall, Gladwin County (3 days prior)	up to 8 in
People evacuated	~11,000
Warning time before evacuation	~18 hours
Homes/buildings damaged	2,500+
Damage estimate	~$200 million
Deaths	0
Estimated lives saved by early evacuation	10-20

The Edenville Dam’s earthen embankment failed first, washing away a 900-foot section, and the resulting surge overwhelmed the downstream Sanford Dam within hours, a cascading failure of two separate structures on the same evening. Both dams were privately owned and had a documented history of safety concerns before the failure.

What these two have in common

Neither of Michigan’s defining modern disasters was a hurricane, earthquake, or wildfire, both were failures of built infrastructure that Michigan residents had every reason to assume was safe: a water system and a set of aging dams. That’s a genuinely different risk character from most other states covered on this site, and it’s a direct argument for why household-level water storage, filtration, and evacuation planning matter even when the immediate cause of a disaster isn’t the weather.

Sources

Flint water crisis timeline, exposure figures, and Legionnaires’ disease death toll: Wikipedia, sourced to CDC and Michigan state records; NRDC
Edenville and Sanford dam failure data: USGS; Mackinac Center