Rehabilitation of Delavan Lake, Wisconsin

Lake and Reservoir Management
By: , and 

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Abstract

A comprehensive rehabilitation plan was developed and implemented to shift Delavan Lake, Wisconsin, from a hypereutrophic to a mesotrophic condition. The plan was threefold: (1) reduce external phosphorus (P) loading by applying Best Management Practices in the watershed, enhance an existing wetland, and short-circuit the inflows through the lake, (2) reduce internal P loading by treating the sediments with alum and removing carp, and (3) rehabilitate the fishery by removing carp and bigmouth buffalo and adding piscivores (biomanipulation). The first and second parts of the plan met with only limited success. With only minor reductions in internal and external P loading, P concentrations in the lake returned to near pre-treatment concentrations. The intensive biomanipulation and resulting trophic cascade (increased piscivores, decreased planktivores, increased large zooplankton populations, and reduced phytoplankton populations) eliminated most of the original problems in the lake (blue-green algal blooms and limited water clarity). However, now there is extensive macrophyte growth and abundant filamentous algae. Without significantly reducing the sources of the problems (high P loading) in Delavan Lake, the increased water clarity may not last. With an improved understanding of the individual components of this rehabilitation program, better future management plans can be developed for Delavan Lake and other lakes and reservoirs with similar eutrophication problems.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Rehabilitation of Delavan Lake, Wisconsin
Series title Lake and Reservoir Management
DOI 10.1080/07438140009353961
Volume 16
Issue 3
Year Published 2009
Language English
Publisher The North American Lake Management Society
Description 22 p.
First page 155
Last page 176
Country United States
State Wisconsin
Other Geospatial Delavan Lake, Elkhorn, Jackson Creek
Online Only (Y/N) N
Additional Online Files (Y/N) N