Iowa DNR - Silver Lake Watershed Project

Watersheds and nonpoint pollution

The major water quality problem in Iowa is nonpoint source pollution, and it has landed a number of streams and lakes on Iowa's impaired waters list. Nonpoint source pollution happens when rainfall, snowmelt or irrigation water runs over land or through the ground and picks up pollutants and deposits them into streams, lakes or groundwater. Those pollutants include excess soil, bacteria and nutrients (from farm fertilizers and manure). Keeping these pollutants out of our water is important for many reasons. Humans depend on clean water for drinking water and recreation like swimming, boating and fishing. Aquatic life, such as fish, depend on clean water to survive.

Nonpoint source pollution can come from practically any outdoor area that comes into contact with running water, unlike point source pollution, which can be traced back to a specific location or "point," such as an industrial facility, wastewater treatment plant, etc.

The area that nonpoint source pollution comes from is called a "watershed," which is an area of land that drains into a lake or stream. To truly improve Iowa's water quality, we need to clean up watersheds to keep sediment, nutrients and bacteria from washing into streams and lakes.

Follow these links for information on Silver Lake from the Iowa DNR: 

http://watershed.iowadnr.gov/projects/wis_silverlake.pdf

http://www.iowadnr.gov/wildlife/wmamaps/maps/silver_lake_paloalto.pdf