How a spring rainstorm turned into a 500-year flood in mid-Michigan
MIDLAND, MI – Thunderstorms are a typical part of spring in Michigan. The rainstorm that hit mid-Michigan from Sunday, May 17, however, turned out to be one for the history books.
Flooding that resulted from up to 7 inches of rain in Midland, Saginaw and surrounding counties damaged homes and property, forced more than 10,000 people to evacuate and dramatically destroyed an electric dam and severely damaged another.
This is called a 500-year flood event, which means it is only likely to occur once every 500 years.
How did it go?
The story begins with the storm itself. A key ingredient fueled the downpour. MLive meteorologist Marc Torregrossa say it the heaviest rains were produced by tropical humidity, as Tropical Storm Arthur raged off the mid-Atlantic coast.
In what he called a conveyor belt effect, a mass of moisture moved from the east coast westward into Michigan, allowing the ongoing storm to tap into that tropical moisture and cause a substantial increase in total precipitation.
Mid-Michigan received a large amount of moisture from the storm, with Midland, Bay and Saginaw counties floating around 3 to 4 inches of rain. The heaviest precipitation totals were found in the north, with Au Gres receiving 8.10 inches, East Tawas receiving 7.97 and Sterling pointing at 7.20 inches.
The precipitation itself has caused headaches in various municipalities, with Bay City Wastewater Treatment Plant requiring the use of an auxiliary pump to cope with the sudden deluge of water on the evening of Monday, May 18.
“Many roads have been washed away. What may appear to be standing water may be much deeper than you might think. As it gets darker, you won’t be able to see the flooded areas. Unnecessary trips use up resources if you find yourself stranded. Please stay home if you don’t absolutely need to travel, ”an alert from the Arenac County Sheriff’s Department said that night.
The Arenac County Sheriff’s Department said US 23 was closed at the time between M-65 and Standish due to possible bridge and water damage on the road and at Omer. The Sheriff’s Department evacuated the areas around Townline, Pinnacle, Franklin Trail and Miller Roads today due to same-day flooding.
As floodwaters began to flow through the watershed, areas downstream of the Tittabawassee River were also made aware of potential serious flooding on Monday evening, as all the gates at the Sanford Dam were open due to the high water. This action served as a warning as the next phase of the disaster began to take shape.
A catastrophic chain of events
Midland County Central Expedition issued an alert at 12:22 am on Tuesday, May 19, stating that residents of the Township of Edenville were to vacate their homes due to an “impending dam failure” at the Edenville Dam and that those living along Sanford and Wixom lakes had to leave their homes and immediately head to the shelters.
Residents were referred to emergency shelters which were set up at Meridian Junior High School in Sanford and Coleman Community High School in Coleman.
At 6:50 a.m. Tuesday, Midland County Emergency Management determined that structures such as the Edenville and Sanford Dams were structurally sound, but that the dams could not control or contain water no longer flowing through the relief valves.
Later in the day, things got worse. A section of the dike at the Edenville Dam collapsed just after 6 p.m. after it could no longer hold back the swollen river.
The collapse prompted flash flood warnings from the National Weather Service which read: “Flash floods threatening life in areas downstream of the Edenville Dam along the Tittabawassee River,” the warning reads. “The nearest downstream town is the Sanford Dam … located about 7 miles from the Edenville Dam. Areas downstream of the Edenville Dam along the Tittabawassee River need to be prepared for additional flooding. “
Midland County Emergency Management later confirmed on Tuesday May 19 that water was flowing over the earthen fill at the Sanford Dam after the Edenville failure sent a torrent of water into the lake Sanford. After submerging the Sanford Dam, water poured south along the Tittabawassee River towards downtown Midland.
Flooding from the event closed roads such as the US-10 eastbound and westbound between River Road and M-30 on Tuesday, according to the Michigan Bay Region Department of Transportation Twitter page. The M-30 Bridge was destroyed near Stryker Marina.
“Please go to a safe place now,” she told a press conference at 10 p.m. on Tuesday, May 19.
About 10,000 people were evacuated, to Midland along with the village of Sanford, Edenville and Dow Chemical. Authorities were also trying to evacuate areas of Tittabawassee Township, Thomas Township and Saginaw Township at the time, Whitmer said.
The Tittabwasee River is said to have peaked at about 35 feet on Wednesday evening. The ridge surpassed the river’s all-time record in 1986, but does not hit the awful 38 foot bar that was intended.
As the Edenville Dam fell into flood water, the Sanford managed to hold on but did not come out of the situation unscathed. A hole formed at the edge of the dam Thursday, May 21, which makes water flow freely from the lake.
Midland City manager Brad Kaye confirmed on Thursday that from 10 a.m. that the structure was still standing. He said there was water above the part of the earth berm with substantial washout, but the concrete structure of the dam itself remains standing
More than just a structural failure
The flooding resulting from the Edenville Dam collapse displaced an estimated 10,000 people and prompted federal energy regulators to order Boyce Hydro to conduct a third-party investigation.
It was reported in 2018 that federal energy regulators ripped off the license of the operator of the Edenville dam for fear that the spillway could not allow enough water to pass to avoid a failure during a historic flood. Federal Energy Regulatory Commission (FERC) records showed that capacity issues at the Edenville Dam spillway have been cited as a problem since the late 1990s.
Michigan Governor Gretchen Whitmer promised the state would pursue all legal remedies and suggested that such critical infrastructure should not be in private hands.
“We can discuss the benefits of whether or not private companies should have critical infrastructure – I don’t think they should – but that’s what we’re dealing with here,” she said.
The governor also conducted an aerial tour of the floodplain along the Tittabawassee River by helicopter on Wednesday and gave a press conference at Midland High School, which serves as a shelter for residents displaced by the flooding.
President Trump also weighed in with a tweet thanking first responders for helping evacuate people in the danger zone under the checkpoints.
On Friday, the owners slowly began to return home, as best they could and as the flood conditions allowed. Families returned home to find muddy and water damaged homes while they work to pick up the pieces together.
President Trump approved Thursday, May 21 an emergency declaration for water-affected areas. Federal aid will begin to supplement state and local responses from Saturday, May 16.
The City of Midland to begin cleanup efforts soon, also. The city will make announcements regarding access to landfills and the collection of debris to help residents with clean-up efforts, said Selina Tisdale, the city’s public information officer. Residents can now report damage to their property online here.
The American Red Cross has compiled a list of locations in Midland and Saginaw counties where displaced residents can seek shelter, food or other assistance and offers an online service to help friends and relatives try to contact missing loved ones.
Downstream flooding occurred in Saginaw County, where the community of Shields was inundated and residents of part of Spaulding Township were asked to evacuate after a dike burst.
Memorial Day weekend in 2020 will be a busy time of cleanup, repair and reflection for those affected by the flooding. While there are no reports of serious injuries or fatalities attributed to the event, damage to homes, businesses and property will take time to repair.
A family living in Sanford was busy picking up muddy debris from their destroyed home, hoping to recover family photos.
“Thirty-one years and our whole life is gone,” Pat Perry said early evening Thursday, May 21. “What bothers me the most are things like pictures that you can’t replace. These are the most important. The other stuff is just stuff.