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Water Quality Modeling Tools

Water quality modeling tools can be used to better understand and evaluate the impacts of management decisions on Wisconsin's surface waters. Each model was developed for a specific purpose and requires an understanding of the inputs, outputs and model assumptions. It is recommended that users review the documentation associated with each model to ensure proper application.

Models developed by DNR

Jensen Shallow Lake Model [XLS]
A simple empirical model relating the seasonal variation in shallow lake total phosphorus concentrations to external loading, accumulated phosphorus in the sediment, hydraulic retention time and water temperature.

EVAAL - Erosion Vulnerability Assessment for Agricultural Lands
EVAAL prioritizes areas within a watershed that may be vulnerable to water erosion.

PRESTO – Pollutant Load Ratio Estimation Tool
PRESTO compares the average annual phosphorus loads originating from point and nonpoint sources within a watershed.

WiLMS – Wisconsin Lake Modeling Suite
WiLMS is a lake water quality planning tool that uses an annual time step and predicts spring overturn, growing season mean and annual average total phosphorus concentration in lakes.

Lake and Watershed Characteristic Spreadsheet [XLSX]
This spreadsheet contains lake and watershed characteristics for all named Wisconsin lakes over 5 acres in surface area, including lake morphometry, water residence time, watershed land cover and estimates of phosphorus loading. It can be used as a primary reference for Wisconsin lake characteristics and as a source for inputs to lake water quality models.

Other water quality models

STEPL – Spreadsheet Tool for Estimating Pollutant Loads
STEPL calculates nutrient and sediment loads from different land uses and the load reduction that would result from the implementation of various best management practices (BMPs).


2015 modeling and analysis tools for nonpoint source implementation

In early 2015, DNR offered 7 training sessions around the state focused on modeling and analysis tools for nonpoint source implementation.

2016 EVAAL hands-on training

In July 2016, Wisconsin DNR offered both in-person and online training on the use of the EVAAL model and included an overview of the model, walk through model steps, common problems and errors, and exercises on your own.