A.W. Research Laboratories, Inc.

Land Use Planning and the Werring Procedure

The water quality of a lake or river is ultimately a reflection of the land uses within its watershed. Although the relative impacts from common land uses are widely known, the specific impacts on a lake vary as a function of local soils, topography, vegetation, precipitation, and other factors. The Werring Procedure is one of the most practical land use planning tools available to delineate existing land uses, quantify each land uses' water quality impact, and examine how future development could further influence a lake's ability to support recreation, fishing, and other water based values. The Werring Procedure is a methodology developed in Crow Wing County, Minnesota which accurately delineates and quantifies land uses and associated water quality impacts.

In the first phase of the Werring Procedure hyper-spectral video data is collected from aerial overflights to classify land uses into four categories; impermeable areas (roads, parking lots, and roofs), open fields and yards, forested areas, and wetlands. Once the hyper-spectral data are classified and mapped, the next step is to verify the land use classifications through "ground truthing", or on-site confirmation. Finally, water quality samples are collected during runoff events in order to provide site-specific quantification of the chemical concentrations from each of the land use classifications in each of the watersheds soil types.

The long-term value of this analysis is to provide guidance on the magnitude and environmental significance of changes in land uses within the watershed of interest. A "build-out" analysis can also be completed in which existing zoning is used to identify how land uses are likely to change in the next few years, and the associated water quality impacts which can be expected. In this manner, AWRL can accurately predict whether the lake will continue to support water quality goals of the community (and natural resource management agencies) based on existing zoning.

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land use planning