Flash Flood — Midland, Michigan

2020-05-19 to 2020-05-20 · near Sanford, Midland, Michigan

Event narrative

The Sanford Dam failed due to the failure of the Edenville Dam upstream in response to widespread heavy rain. This lead to historic flooding along the Tittabawassee River as the river stage at Midland reached 35.05 feet on May 20th. Approximately 1000 buildings or homes were severely damaged or destroyed, with about 1500 homes or buildings being affected or suffering minor flood damage in total across Midland County.

Wider weather episode

A stalled low pressure system and frontal boundary across the southern Great Lakes region brought record rainfall to southeast Michigan beginning the morning of May 17, 2020 and continuing into the afternoon hours of May 19, 2020. Total rainfall reached 1 to 6 inches across southeast Michigan, with the 4 to 6 inches focused across the Tri-Cities region. As a result, several rivers across the region flooded including significant flooding occurring along the Saginaw River and historic flooding along the Tittabawassee River in Midland county. The heavy rain in the Tri-Cities region resulted in the catastrophic failures of the Edenville and Sanford dams northwest of the city of Midland, which lead to extensive damage to structures and roads. The evacuation of 10,000 residents in the city of Midland before the dams gave way prevented any loss of life. The heavy rain also resulted in hundreds of road closures across the region.

In addition to the heavy rainfall, a tight pressure gradient resulting from the area of low pressure further exacerbated already high Great Lakes water levels and enabled strong east to northeast winds to produce significant lakeshore flooding along the shorelines of Lake Huron (particularly Saginaw Bay), Lake St. Clair, and western Lake Erie. Significant river flooding once again occurred along the St. Clair River as well along Anchor Bay in portions of Macomb and St. Clair counties. While a stalled low pressure system bringing soaking rainfall often occurs at least once or twice during the spring months in the vicinity of southeast Michigan, the combination of heavy rainfall, significant lakeshore and river flooding, and the resultant dam failures in Midland county make this event historically significant.

View location on OpenStreetMap → (43.6800, -84.3600)

Source: NOAA Storm Events Database, event_id 886588. Narrative written by the NWS forecast office that issued the report.