The State of the Lake

Lake Macatawa is classified as “hypereutrophic” by the Michigan Department of Environmental Quality (MDEQ). Eutrophication is a natural process in freshwater systems in which a lake gradually builds up sediment, becoming shallower and filled up with plants. In the process the dissolved oxygen (DO) content of the lake decreases, making the lake less able to support diverse fish populations. The hypereutrophic classification means that Lake Macatawa is eutrophying at a much faster rate than is considered normal. A 2005 MDEQ study rated the diversity of aquatic organisms in Lake Macatawa as “poor” in most of the available categories, supporting the hypereutrophic classification.

Straightening of natural and engineered water courses over the years, a lack of adequate bank protection, a decreasing area of wetlands to absorb runoff, and an ever increasing area of impermeable surfaces in the Watershed; these forces combine to reduce the time it takes water from any part of the watershed to reach Lake Macatawa. This decrease in “concentration time” means that the speed of water in water courses during flood “events” is greater than would naturally occur, and the peak volumes entering Lake Macatawa during an event are greater than they would have been for similar events 150 years ago. The increasing speed of the water leads to more erosion – and more silt carried in these flood waters.