High quality streams under the US Clean Water Act are those waters whose quality exceed that necessary to protect the “fishable / swimmable” goals. High quality streams support healthy populations of aquatic life only found under least disturbed conditions with little pollution. In Connecticut, least disturbed conditions are maintained with high levels of core forest within the stream corridor and upstream drainage basin. Urban sprawl resulting in the reduction of core forest is a key threat to maintaining high quality conditions in Connecticut streams.
Sages Ravine, Salisbury CT
About the map
The map identifies streams predicted to be high quality based on current land cover conditions in the upstream drainage basin. Predictions are based on a model developed using over 30 years of Connecticut aquatic life and land cover data. The map allows users to conduct 'what if' scenarios by exploring the loss of high quality stream kilometers when the percent core forest is reduced in the upstream drainage basin.
How to use the map
The slider contained within the legend on the left side of the map reduces the amount of percent core forest from current land cover in the upstream basin of each stream. The resulting map displays the predicted stream condition based on the reduction of core forest selected with the slider. Hover the mouse over a stream catchment to get specific information for a particular stream segment including the probability that a stream segment is high quality and the amount of high quality stream kilometers lost due to core forest reduction. The color of each stream segment catchment indicates the probability that the stream supports high quality conditions. Stream catchments that are orange are likely not to support high quality condition, while stream catchments that are more blue are likely to support high quality conditions.
Additional information on this project and data included in the map can be found at Additional information on this project and data included in the map can be found at https://github.com/marybecker/HQStreamEval.