WEST MICHIGAN — (Mar. 22, 2014) Snow melt and additional precipitation this week have allowed rivers around West Michigan to continue to rise. Earlier this week an ice jam caused the Grand River to jump almost a foot in less than 2 hours prompting flood warnings along the Grand River in Kent and Ottawa Counties. The ice however moved downstream without any further problems and flood warnings were cancelled. Ice jams can cause rapid increases and decreases along area rivers but its the slow and gradual increase that sometimes goes unnoticed that is causing the greatest concern this spring.
Spring snow melt and additional precipitation cause rivers and streams to become inundated this time of the year. What compounds the problem this year is the record-breaking snow and cold. Although the snow pack around West Michigan is slowly but surely melting the problem then becomes where does all the melting go? With temperatures still well below average and snow covering a majority of the ground, the soil and sub-soil remain fairly frozen not allowing for soil absorption. Infiltration of snow melt into the ground is a large part of what makes up a balanced water cycle. Snow melt then becomes run off and travels directly into stream and rivers. This process is usually somewhat slow but adding additional snow and rain increase the time and effect significantly. As we saw last year during the historic flooding, the problem became more about the amount of rain we received than the amount of snow melt. Thankfully, precipitation has been fairly light in the last few weeks allowing for most rivers to be fairly normal but there are still a few rivers that are already causing for some slight concern and extra monitoring.
The Kalamazoo River at Marshall in Calhoun County is the newest Flood Advisory to be posted. The river has risen around a foot in the last few days bringing the river to bank-full level. This means very minor flooding will occur in low-lying areas surrounding the river. In this case, low-lying pastures and farm fields which border the Kalamazoo River in this area will likely see some minor flooding. The river is forecast to slowly fall after it peaks this weekend.
The Grand River at Grand Rapids where only 11 months ago a historic flood occurred will likely see some very minor flooding in the next few days as well. River levels remain well below flood stage and will not come anywhere near the levels we saw last year at least at this point. River levels however will increase above 12 feet to 13.6 feet. This brings the Grand River above bank-full stage creating very minor flooding along low-lying areas and walk-ways along the river. The river will remain somewhat elevated through next week but will the effect will likely be very minor with hardly any impacts.
The Thornapple River is another river in the watershed that has seen elevated levels in the last few days. River levels have slightly increased above bank-full and creep towards flood stage. At this point the river in Hastings should peak slightly below flood stage Monday morning. At bank-full the elevated river will cause minor flooding in Tyden Park. The river is forecast to fall slightly by mid-week but will remain fairly full.
Ionia is no stranger to flooding and once again it is an area that we will continue to monitor. Flood advisories were issued because the river has risen almost 2 feet in just a few days. With a great deal of ice cover still present in and along the Grand in Ionia, this area becomes one that will be very closely watched. The river is expected to rise to 19 feet by Monday morning and although that is below flood stage it still has minor effects on areas around the Grand River. The Ionia County Fairgrounds are notorious for flooding every year due to their elevation and proximity to the river. When the river reaches above bank-full like it has this week we start to see some of the fairground buildings impacted. When the river rises above 18 feet the Automobile building becomes surrounded by water. River levels will remain above bank-full but below flood stage in Ionia through mid-week.
The good news is that the week ahead looks fairly quiet with the exception of Tuesday and temperatures will remain below average allowing for a slow and gradual melt. We will continue to keep you updated on the flood risk as we enter into the spring melt here on fox17online.com.