Evolution and critiques of terrain mapping techniques in the upper Esopus watershed concerning turbidity reduction in the NYC water supply

Abstract

The most recent Pleistocene glaciation ended approximately 12,000 years ago, a cooling interval that deposited lacustrine clay and glacial till throughout the Catskill watershed. These fine-grained glacial legacy sediments erode during heavy rainfall events and create turbidity in the streams. The streams of the Catskills feed into various reservoirs that provide clean drinking water to millions of residents in New York City. Turbidity reduction in the Catskills is a NYS-funded effort to ensure the cleanliness of the New York City Water Supply. Since the early 2000s, the New York Cite Department of Environmental Protection (NYCDEP) has worked collaboratively with the Ashokan Watershed Stream Management Program (AWSMP), contracted firms, and municipalities to uphold its initiative to reduce turbidity in the Ashokan Watershed. This analysis of stream management explores the evolution of terrain mapping techniques used in the Stony Clove watershed and Broadstreet Hollow Creek watershed, both tributaries to the Upper Esopus Creek. The survey, monitoring, and restoration project phases of stream management all play a crucial role in the success in turbidity reduction. Over the past two decades, these approaches to stream management have evolved as new innovations have been made in the industry. Even so, there are still mentionable critiques of stream management that can be applied to future stream assessments, monitoring studies, and restoration projects.