The amount of water pouring into Lake Michigan and Lake Huron is amazing. Record amounts of water are being delivered by some Michigan rivers.

Let’s look at exactly how much water has been shipped into Lake Michigan and Lake Huron by some of the bigger rivers in Lower Michigan.

Before we get started, here’s a reminder on what constitutes a water year. A water year runs from October 1 to September 31.

One of the most astonishing bits of info is the Grand River at Grand Rapids has already poured more water into Lake Michigan than an average complete year of water. The 2020 water amount below sits right at the average for a year.

National Weather Service - Grand Rapids, MI

You also can see one of the reasons why Lakes Michigan and Huron have now reached record water levels. The last three years of river flow are highlighted in blue. The river flows over the last three years have been on the very upper end of a data set.

River flow of Grand River at Grand Rapids

To put it in perspective, the Grand River at Grand Rapids has had 102 billion cubic feet of water flow by on the way to Lake Michigan. There is a little over seven gallons in a cubic foot of water. This means over 700 billion gallons of water have poured into Lake Michigan from the Grand River since October 1, 2019. Remember- one inch of water on Lakes Michigan and Huron has 800 billion gallons. So essentially the Grand River is responsible for almost one inch of new water on Lake Michigan and Lake Huron.

The Saginaw River at Saginaw is a big river and has some staggering numbers.

River flow on Saginaw River at Saginaw shows very high river flow.

The Saginaw River has seen 310 billion cubic feet of water pass by since October. That’s over 2 trillion gallons of water flowing into Lake Huron out of the Saginaw River.

These major rivers aren’t the only rivers with above average flow.

River flow compared to average flow for Michigan river gauges.

Most of Michigan’s rivers have water flowing by at a much above normal rate (blue dots). The black dots represent high water flow.

In other words, most all of Michigan’s rivers have much above normal to high water amounts pouring into the Great Lakes.

This high amount of water flow has brought Lake Michigan and Lake Huron to record high water levels.