The Paw Paw Lake Foundation is dedicated to the improvement of Paw Paw Lake,
Berrien County Michigan
The Townships of Coloma and Watervliet approved the creation of a Special Assessment District (SAD) for Paw Paw Lake that provides funding for important water quality improvements. SONAR is applied to rid the lake of Eurasian Milfoil. The SAD funded projects were implemented starting in 2012 and have recently been extended to continue for another five years.
The Problem with Nutrients
The problem with Eurasian Milfoil in Paw Lake wasn’t caused by high level of nutrients in the lake, The Milfoil was just well fed by the nutrients. The Eurasian Milfoil, which is not indigenous to inland lakes in Michigan, was transported to Paw Paw Paw Lake from the props and the bottoms of boats. Once it entered the lake it continued to thrive and spread because it was so well fed by the abundance of nutrients in the lake.
The nutrients also feed the algae in the lake. Algae is the green mucky slim that appears in the lake periodically over the summer. Algae effects the water clarity and causes skin and eye irritation.
The high level of nutrients in the lake have two basic causes, bottom sediment and high level inputs from the County drains. The County drain known as the Branch & Derby is the largest contributor. A new sediment basin in this drain has reduced the sediment load in the drain water. This has been confirmed by testing the sediment level in the drain water before it enters the sediment basin and after it leaves the sediment basin.
Everyone wants the water quality of Paw Paw Lake to be crystal clear and healthy. Eliminating the Eurasian Milfoil is a major improvement. Reducing the nutrient level in the lake would also be a major improvement. The high nutrient level in the lake, however, cannot be reduced easily. Large amounts of nutrients are released from the bottom sediments in the lake. Removing the bottom sediments would help solve the problem, but the cost is prohibitive.
An Aeration trial had the potential to reduce nutrients in the lake, but it was not successful. Options are being considered by the SAD committee.
Nutrients and sediment also enter the lake throughout the year from the county drains. Two projects have recently been completed: a new sediment basin in one of the Berrien County drains and a new sediment barrier on a large upstream farm property.
The impact of these PPLF initiatives are confirmed. The sediment load in the drain water has been reduced due to the effectiveness of the sediment basin. The sediment barrier also was successful in reducing the sediment dump from the farm property.