Flash Flood — Gladwin, Michigan

2020-05-18 to 2020-05-19 · near Dale, Gladwin, Michigan

Event narrative

Multiple dams on the Tittabawassee River system were in danger during and after the heavy rain event. Significant releases of water from Secord and Smallwood Dams caused periods of rapid, flash flooding downstream of those dams on parts of the 18th and 19th. Tremendous erosion of the river banks occurred, and some roads and properties were damaged. Those releases did manage to save those two dams. However, downstream, Edenville Dam was unable to be saved. That dam failed catastrophically on the evening of the 19th, releasing the contents of Wixom Lake to downstream portions of the Tittabawassee River.

Note that Edenville Dam was located just north of the Gladwin/Midland County line. The Tittabawassee River enters Midland County immediately after leaving the dam. Thus, the vast majority of the downstream flooding caused by the failure of Edenville Dam will be found in Midland County and other downstream counties. Also note that the indirect damages of the Edenville Dam failure in Gladwin County are considerable, but difficult to quantify. To just touch on one topic, there were hundreds of lakefront properties on Wixom Lake, behind the dam. That lake no longer exists, and those properties have seen loss of property value, and residents and vacationers see a lesser quality of life.

Wider weather episode

A very slow moving low pressure system advanced east from the central Plains. Unusually deep moisture was pushed northward into the Great Lakes region, ahead of this low. Multiple rounds of heavy rain fell in parts of northern lower Michigan on the 17th and 18th. This heavy rain targeted east central and northeast lower Michigan in particular. Rainfall amounts of 2 to 4 inches were common by the morning of the 18th in places like Tawas City, Houghton Lake, Omer, and West Branch. Further heavy rain continued, and by the morning of the 19th rainfall amounts were 8.10 in Au Gres, 7.43 in East Tawas, 7.20 in Sterling, and 7.60 near National City. Generalized flooding was widespread and considerable in that part of lower Michigan. In some spots, flooding impacts lasted for days. Runoff from this very heavy rain resulted in the catastrophic failure of Edenville Dam on the Tittabawassee River.

View location on OpenStreetMap → (43.8113, -84.3697)

Source: NOAA Storm Events Database, event_id 897170. Narrative written by the NWS forecast office that issued the report.