The master's project team worked with The Natural Capital Project to develop a new suite of InVEST ecosystem service assessment models for lakes.  Inland Michigan lakes provide many services that people care about, including recreation and aesthetic opportunities.  However, land use changes and other decisions often do not fully account for the impacts on the benefits that humans derive from lakes.

The goal of the project was to help decision-makers and practitioners link upstream actions to their influences on downstream freshwater ecosystem services.  To do so, the team built three simple models that use easily accessible data.  The first predicts phosphorus export from land use classes.  The second model takes the phosphorus export from surrounding land use classes to predict the concentration of phosphorus in a lake and translates it to lake trophic state.  The third model estimates how lake trophic state influences property values near lakes.  Together, these models can be used to assess current inland lake freshwater quality and predict changes in future lake water quality and property value based on different land use scenarios.  We surveyed Michigan stakeholders throughout the model-building process to better understand the issues that these models could help them tackle and how to make the models usable.