Mecosta County is under a flood watch until Sunday evening - Muskegon River levels are rising upstream of Rogers Pond, possibly due to an ice jam. The river levels have risen so much that the yards of the houses along Riverside Dr. are flooded.
So let's tackle the major questions regarding ice jams- According to the National Oceanic and Atmospheric Association, it's a stationary accumulation that blocks or restricts streamflow. Ice covers the rivers and lakes in the northern U.S. every year, and normally there is a freeze, ice break-up, and the ice pieces flow downstream without issue. However, at times those pieces can become lodged in place, creating a back-up.
The rates of water level rise during an ice jam completely vary - from inches to feet per hour. River level trends become very uncertain in ice jam situations - hence a flood watch being issues for Mecosta county.
Ice jams have occured in forty-three states in the U.S., most frequently reported in Montana and New York, with Pennsylvania and Minnesota not far behind. And it's not limited to the north - the mountains of Arizona and New Mexico have reported ice jams too.
Not only can ice jams affect major water passageways, but they can also cause major flooding, death, habitat damage, and damage to stream beds.