Lakeshore Impervious Surface Research Study

Crow Wing County recently completed Phase IV of a lake shore research study project to calculate the amount of impervious surface coverage on larger lakes in Crow Wing County. This study was conducted in response to the 2011 Land Use Ordinance revisions which require performance standards depending on the amount of impervious coverage per lot. Impervious surfaces are hard surfaces on a lot such as rooftops, sidewalks, patios and driveways that don’t allow water to soak into the ground.

Phase I
For Phase I of the project, impervious surface data was calculated on 12 lakes using high-resolution aerial photography and property sketches from the Property Valuation and Classification Office. The amount of impervious surface was calculated for the entire riparian lot as well as within 250 feet and 500 feet of the shoreline to determine how much impervious surface was located close to the shoreline.

Phase II
Phase II included another 20 lakes. The results of both phases of the project indicate that the average impervious surface percentage on riparian lots on the County’s larger lakes is less than 10%. Maps of each lake measured along with the summary report are available below.

Phase III
Phase III included another 17 lakes, all within the city limits of Crosslake.  A separate report was not prepared for Phase III.

Phase IV
Phase IV included all or portions of another 30 lakes.  It added the municipal portions of lakes that were not previously included.

The lakes measured correspond with the lakes that were part of a water quality screening project that was conducted in 2009 and 2012 to determine whether a water quality trend could be determined based on all the available water quality data that had been collected over the years. These reports are available online.