Office of Drain Commissioner

Storm Water Education: Watershed Management

Lots of different factors are at play when it comes to managing a watershed and keeping it healthy, productive, and free of invasive species. Here’s a look into some aspects and common threats to watersheds and what we can do to mitigate them.

Eutrophication

What? Excessive nutrients in a water system (typically phosphorus) that lead to harmful algal blooms.

How? Most commonly, excess nutrients are released into these systems via fertilizer use, sediment from farms and construction sites, failing septic tanks, and animal waste/manure getting washed away by rain or irrigation. This surface run-off may then enter county drains, lakes, and streams.

Impact? Systems that are receiving too many nutrients end up having massive amounts of plant growth. Plankton, algae and other small plants called microphytes all create massive blooms on the surface of the water. These blooms take over and end up outcompeting natural and more complex plants. The algal blooms block sunlight from getting through and more plants die, which adds even more nutrients to those cycles. Lastly, as all of the dead plants are decaying at the bottoms of the lake the decomposition process dramatically decreases the amount of dissolved oxygen (DO) in the water. The decrease in DO impacts all other aquatic species like fish and mussels.

Solution? The best solution to this problem would be prevention- limiting non-point sources of nutrients such as run off of fertilizer, manure, and sediment from farms and agricultural areas or yards. Secondarily, herbicides and shading have been used in some instances to try to reduce the amount of algae in a body of water. Control methods such as herbicides and dyes which provide shading are short term fixes, while nutrient reduction methods are long term solutions. Use of compost fertilizer instead of synthetic nitrate and phosphate fertilizers also helps reduce excess nutrients entering the systems. Lastly, as a land management tactic, repair and restore riparian zones to help absorb those extra nutrients before they reach the water.

Invasive Species

What? Any species that is non-native to an area and has harmful or damaging impacts on the ecosystem and the aquatic or terrestrial quality around it.

How? Invasives outcompete local plants and animals for resources and space. They often grow quickly, can survive in harsher conditions and don’t have natural predators in the area. Because of these factors, they often crowd out native species and cause them to die back in areas that they would have naturally been thriving!

Impact? When invasives like Eurasian Watermilfoil or Zebra mussels infiltrate a lake habitat, they severely alter the water quality and ecosystem functions of the lake. This negatively impacts recreators, native plants and animals, as well as property owners.

Solution? The most successful and effective form of a solution with invasives is prevention. If boats and watercrafts are cleaned off and emptied correctly, then they would not accidentally transfer invasives from one lake to another. Depending on the invasive and where it is located, there are methods of biological, chemical, and mechanical removal of plants as well.

USDA National Invasive Species Information Center
MDNR, EGLE, MDARD Invasive Species Collaborative Network
Stop Aquatic Hitchhikers
Integrated Pest Management for Lake Watersheds - A look into Michigan Aquatic Invasives and how to mitigate and manage them

Surrounding Terrestrial Ecosystems

The water quality and quantity of our County relies on the land and plants around it. Land is a natural absorber and filter for surface water.

Green spaces surrounding lakes, river, streams and drains are important as they provide shade, habitat and nutrients to those ecosystems, allowing them to remain productive and healthy.

In big cities, most of the land is covered in impervious materials like pavement and asphalt. These materials don’t absorb water, but instead quickly usher water off and into streams, lakes, and low areas. This common problem makes riparian buffers and infiltration areas such as rain gardens even more important.

Waterfront Owners

Native shorelines are important as they reduce pollutants, slow water down and prevent erosion at the water’s edge.
Quick Tips:
- Try using native deep-rooted plants and shrubs instead of retention walls.
- Turn to natural fertilizers or compost when possible. Remember that it is against state law to use phosphorus-containing fertilizer unless a soil test proves the need for phosphorus.
- Never dump yard waste or compost on a stream or riverbank
- Don’t plant short grasses like Kentucky Blue Grass near a bank or shore. Try to choose longer rooted grasses that give the shore more structure.
- Water your lawn in the morning or evening to ensure maximum absorption and retention.
- Make sure to replant or re-seed areas that plants have died or washed away. Try to only use plants native to the mid-west.
  - Find the right mix of native plants for your property.