Watershed Assessment Tool

Water quality is strongly related to land use. High-resolution land cover data for Connecticut has made it possible to look at the land/water connection at a fine scale.  Use the tool to learn about the study, explore the landscape surrounding the over 4,300 local waterways in our state and the implications for the health of these waterways, and test out landscape change scenarios to see what effects they might have.

Local Watershed Assessment Tool


Visit the Story Map to learn about the project, methods, and analyses.


Use the Dashboard to learn about the health of watersheds.


Use the interactive scenario builder to see the effects of potential land cover changes on watershed health.


Visit strategies section to learn more about watershed protection strategies.

Project Summary

A recently acquired high resolution (1 meter) NOAA land cover dataset for Connecticut was used as the basis to develop watershed landscape metrics that relate to overall aquatic ecosystem health and nitrogen loadings. The metrics combine basin-wide land cover characteristics with those within the 100-foot riparian corridor, and were applied at the “local basin” level of organization, which after modification included over 4,300 basins. Basin status was summarized using two indices, the Combined Condition Index (CCI) indicating overall aquatic health, and the Enrichment Factor (EF) indicating the degree of nitrogen loading. Maps and data covering the entire state were developed into an interactive, online decision support tool that shows both CCI and EF for all local basins, and also allows the user to estimate the impact of future land cover changes. The purpose of this project is to support multiple ongoing projects and priorities identified by both CTDEEP and LISS with relevant, actionable landscape-oriented information at an unprecedented level of granularity that relates to the world of local land use decision makers.

Support for this project was provided by the Long Island Sound Study and the Connecticut Department of Energy and Environmental Protection. We are indebted to the NOAA Office for Coastal Management for providing the high resolution land cover for Connecticut, without which this project would have been impossible. This project is based on concepts developed by our partner Footprints in the Water, LLC.