In 2021, New York assessed Cannonsville Reservoir as impaired after a 7-foot culvert blocked fish passage. 2 years later, the new culvert scored 0.88 for aquatic passage

Stream restoration projects can provide benefits that extend beyond the immediate area where construction takes place. A culvert that changes natural water flow can contribute to erosion, sediment movement, water-quality problems, and barriers to aquatic life. In Delaware County, New York, replacing an undersized culvert along an unnamed tributary to the Little Delaware River addressed these concerns while improving fish passage and reducing sediment flowing toward the Cannonsville Reservoir, a drinking-water source for New York City.