This week marks the 10-year anniversary of the Grand River Flood of April 2013. The flood was caused by heavy April rain, falling on saturated ground.
In 2013, the second half of winter was cold and snowy. From January 31 – February 28, Grand Rapids had over three feet of snowfall. The map above shows significant snow cover over the entire Grand River basin on February 8, 2013.
It was cool in March. From March 12-25, the temperature didn’t get warmer than 40°. So the the snow melted slowly and the ground remained saturated.
Then the heavy rain hit. We had measurable rain in West Michigan on 14 consecutive days from April 6-19. Total rainfall for that period was 9.84″. The Grand River rose rapidly, reaching 17.8 feet in Comstock Park. That was 5.8 feet higher than flood stage. Roads in the area (Abrigador Trail, Konkle Drive, Willow Drive, Riverbend) were flooded for days.
The river gauge in downtown Grand Rapids (just south of the Public Museum) reached a level of 21.85 feet. That’s 3.85 feet higher than flood stage. You can see that the highest crests have come in recent years. That can be a little deceiving.
Over the years, a river gauge may be moved from one spot to another. The bottom of the river may change a little as well. A big factor is building flood walls, which Grand Rapids has done. When you build flood walls and the river is constricted – prevented from expanding outward, two things can happen. To accommodate the same volume of water, the river has to either speed up or it has to get higher. Usually, a combination of both happens. Open you’re mouth wide and exhale – now close your mouth (like when you whistle) and exhale – the air will come out of your mouth faster. If you’re interested in exploring this topic, check out how a spray bottle works or how a heavy airplane going at a high speed can fly up into the air. Physics is fascinating.
Volume of water may be a better way to compare floods. Here’s the estimated volume of water for the 5 biggest floods on the Grand Rapids. First, note that the four biggest floods on the Grand River came in pairs…1904 and 1905…and 1947 and 1948. Weather patterns sometimes stay the same for 2 years or more.
We had a lot of snow on the ground and saturated ground in the spring of 2014 and I was worried that we’d have a repeat of 2013, but we had only 2.1″ of rain from Feb. 28 – April 11 in 2014. The snow melted gradually and we didn’t get a major flood.
By volume, the 1904 and 1905 floods top the list. Floodwaters reached across the west side of Grand Rapids all the way to John Ball Park. The flood of 2013 was a 25-year flood – not a 500-year flood or a 100-year flood. It’s only a matter of time until we see another flood of that magnitude.
FINAL NOTE: In 1919, a young Army Officer was assigned to join a convoy of Army vehicles traveling by road from Washington D.C. to San Francisco. Get this…the trip took 62 days to complete! They had horrible, mainly dirt roads…inadequate bridges, etc. This young officer vowed that if he ever got to be in charge, he’s vastly improve the roads and bridges.
That young man (Dwight Eisenhower) became President of the U.S. in 1953. He pushed his dream of an Interstate Highway System into reality. He wanted a median – where a helicopter could land and bring supplies and first responders after a natural disaster like a tornado or earthquake. He also asked for bridges to be well above the highest flood possible.
In Grand Rapids, a record flood could make many of our Grand River bridges unusable – either due to high water or due to debris dams. The two Interstate bridges – I-196 in downtown Grand Rapids and I-96 in North Park/Walker are both high above the Grand River and would likely remain open and safe.