Culvert Upgrade Impacts

This dataset represents opportunities to restore aquatic connectivity by upgrading culverts. Specifically, this product tabulates the results of a model in which each road-stream crossing is systematically upgraded (virtually) to a bridge having the minimum aquatic barrier score, one at a time, and the predicted improvement in aquatic connectedness from the upgrade is recorded. The delta, or difference, in the aquatic connectedness score, before and after the crossing upgrade for each cell within the affected neighborhood, is computed and multiplied by the average index of ecological integrity of the affected neighborhood. The weighting by the Index of Ecological Integrity emphasizes the potential ecological benefits of a crossing upgrade in an area that is otherwise in good condition but depressed by the crossing structure. Conversely, the score is lower where conditions are already so degraded that an upgrade would not improve local ecosystem conditions.