Since 2016, the Lake Manitou Association Board of Directors has contracted with Clarke Aquatic Systems to monitor the plant life in our lake. So far, they have seen a consistent healthy comeback of native plant life following the eradication of hydrilla, which was completed in 2017.
Regular samplings are taken each year and Clarke provides us with a mapping of the findings. You can view the results below.
Accumulated sediment in Lake Manitou impacts recreational capacity, diminishes habitat and can degrade water quality.
The Lake Manitou Association has taken several steps over the past few years to preserve the water quality of our lake. Lake Manitou is comprised of a watershed of nearly 28,000 acres southeast of Rochester and into Miami County, a very large area of runoff for our 775-acre lake. (see the watershed map HERE).
The two main inlets to Lake Manitou are Graham Ditch (east of Bessmore Park Rd bridge/White Creek) and Rain Creek (south end of the lake past the DNR wetlands).
Graham Ditch is one of our lake’s filtering systems designed to control sediment and nutrient flow into Lake Manitou. Graham Ditch consists of a series of basins, earthen berms and a small dam. Every few years, these basins need to be cleaned out as they fill up with silt quickly. Several of our Members periodically measure the depth of the sediment levels and the system’s effectiveness.
In November of 2016, the Association spent $5,000 to excavate two ponds and added a new, large, 24 x 527’ trench basin to further capture solid material. The downside of the current Graham Ditch system is it begins nearly 1/2 mile upstream; past this collection system, runoff and sediment enter the lake at the White Creek bridge. The Graham Ditch is also located on three separate parcels of privately owned property - not on county or state owned land.
What you can do
A few ways to take personal responsibility on Lake Manitou:
Pick up your pet’s waste
Use phosphorous free fertilizer
Dispose of yard waste (leaves, grass clippings) properly - NEVER blow them into the lake
Install glacial stone along your concrete seawall - this will reduce wave activity which helps to prevent erosion
Avoid feeding the ducks, geese and swans
Remove invasive plant species from your property
Don’t use the lake as a bath - soaps, detergents and shampoos are harmful to aquatic life
When operating your boat at high speeds, distance yourself from the shoreline, islands and shallow areas to avoid stirring up the lake bottom and causing harmful erosion