Carter Lake, NE

Carter Lake is a 315 acre oxbow lake along the Missouri River between Nebraska and Iowa. Elevated phosphorus levels resulted in cyanobacteria ( algae) blooms and subsequent microcystin algae toxin production. From 2005-2008, beach warnings were posted for 21 of the 80 weeks of peak summer recreation. A whole lake alum treatment was completed in May 2010, a success story jointly published by Nebraska and Iowa officials can be downloaded below.

The alum treatment resulted in the following changes:

  • Total phosphorus declines of 72%
  • Total nitrogen declines of 52%
  • Algae toxins are virtually non detectable and beaches have not been closed since the treatment
  • Water clarity has improved
  • Newly stocked game fish have flourished
  • The lake is proposed to be removed from USEPA’s Clean Water Act section 303(d) list for impaired waters due to algae toxin