The West Kill's watershed accounts for 10 percent of the reservoir's basin. It has the highest elevations and steepest slopes of any of the Schoharie's subwatersheds, with runoff from seven of the 35 Catskill High Peaks draining into the stream. Due to limited development and extensive land protection in the stream's watershed, its water is relatively clean, supporting a habitat for both wild and stocked trout; historically it has drawn fly fishers and other anglers. However, the West Kill has contributed to turbidity issues with the Schoharie creek and reservoir due to recent floods; several government agencies have worked together to develop a management plan that will mitigate the floods and the turbidity.