Estimates of Lake Inflow and Outflow Discharge Derived from SWOT Satellite Data across North America

The recently launched Surface Water and Ocean Topography (SWOT) satellite provides observations of Earth’s rivers and lakes, which sets the stage for innovative application of such data for hydrologic analysis. Here, we apply the LakeFlow algorithm, which leverages mass conservation principles and Bayesian optimization, to estimate lake inflow and outflow discharge at 1,061 North American lakes from 4/02/2023 to 2/17/2025. These estimates were developed to support National hydrologic model development, with a first application in Riggs and others in review. These discharge estimates support an improved understanding of river-lake dynamics including the timing of management operations. SWOT measurements include lake and river water level and extents, and inflows and outflows are estimated at daily intervals.