This partnership between the City University of New York (CUNY) Remote Sensing of the Earth Science and Technology (CREST) Institute and the New York City (NYC) Department of Environmental Protection (DEP), the water supply operating agency, will use remote sensing to assess and calibrate the watershed hydrology models now being used, with an emphasis on low-flow (dry summer) conditions. The NYC water supply system, one of the oldest functioning municipal utilities, maintains safe and reliable supplies to some 9 million people. Climate change is impacting the hydrology of the watersheds contributing to the system; earlier winter-spring peak streamflow combined with longer, hotter summers could pose new drought risks to water quantity and as well as impact water quality. To enable effective adaptation, the watershed hydrology models being used for scenario planning and operational management must accurately represent important dry-summer hydrological processes, particularly evapotranspiration, across hilly watersheds with multiple land uses; however, field data for assessing these model capabilities are sparse. This investigation will use thermal, microwave, and other remote sensing data to infer soil moisture and evapotranspiration spatiotemporal patterns under drought conditions, building on previous investigations by members of our research team. For the feasibility phase, we will survey available relevant remote sensing products, and after deciding on a suitable subset, prototype their use in the NYC watershed for model verification and calibration. While the watersheds managed by NYCDEP will be the core area for this investigation, we will collaborate with CCNY partners in the Consortium for Climate Risk in the Urban Northeast (CCRUN) to extend regionally the benefits of the work carried out. Our hypothesis is that model calibration and verification with remote sensing products will result in significant improvements in simulation of low-flow water quantity and quality.