Water quality in freshwater systems can impact salmon, forage fish, and drinking water, and impact the ecosystem functions of floodplains, estuaries, and wetlands. 

The Benthic Index of Biotic Integrity (B-IBI) indicator measures stream health by via the diversity and abundance of invertebrates (insects, snails, and worms) that live in stream beds. The B-IBI is correlated with land use conversion and urbanization, indicating worse stream health in watersheds with more urban development and less tree canopy cover. 

Based on these findings, there are four priority strategies likely to improve stream condition: 1) increasing capacity of local stormwater management programs, 2) coordinating watershed planning across jurisdictions, 3) encouraging restoration through education and incentives, and 4) preserving land for forestry and farming. 

There are two additional indicators being developed to support this Vital Sign.