In 1998, the city's Department of Environmental Protection (DEP) issued an advisory[2] warning against eating more than one reservoir-caught smallmouth bass per month after mercury levels of 1.3 part per million (ppm), slightly above the federal standard of 1.0 ppm, were confirmed in three caught in the reservoir.

Since there is no industry in the reservoir's vast watershed, this contamination is believed to be the result of acid rain from coal-fired power plants in the Midwest.

[citation needed] In 2006, after residents raised concerns regarding the soundness of both Merriman and Neversink dams following emergency repairs to Schoharie Dam, a local newspaper, the Times Herald-Record, obtained copies of weekly visual inspection reports for both and found that the handwriting and information relating to the appearance of the dams on weekly reports compiled by inspector Ronald Hewlett and initialed by section engineer Russell Betters over a three-year period were virtually identical, suggesting they had been routinely photocopied.

[4] Rondout Reservoir is a single basin 6.5 miles (10.5 km) long,[5] 2,052 acres (8.30 km2) in area and reaches a maximum depth of 175 feet (53 m) near the dam.

All this water is fed from the Rondout to West Branch Reservoir in Putnam County via the Delaware Aqueduct, the world's longest continuous tunnel at 85 miles (137 km).