CS7B - Concurrent Session 07B: Real Time Flood Inundation Mapping for Coordinated Dam and Levee Operations

Abstract Description: Yuba County, California is situated within a complex, highly regulated river system at the confluence of the Feather and Yuba Rivers, where flood risk is governed by coordinated operations at Oroville, New Bullards Bar, and Camp Far West dams and by the performance of an extensive levee system. Downstream flood hazards are strongly dependent on reservoir release strategies, system constraints, and potential levee failure locations under high-flow conditions. To support dam and levee safety planning and emergency management, the Yuba County Water Agency and Office of Emergency Services (OES) have implemented a Flood Inundation Mapping System (FIMS) that integrates operational forecasts with hydraulic modeling to evaluate evolving flood and levee failure scenarios.

The FIMS generates hourly inundation maps driven by 10-day forecast reservoir releases and simulates levee breach scenarios associated with deficiencies identified through inspection and assessment programs. Real-time hydrometeorologic and river flow forecasts from the California–Nevada River Forecast Center (CNRFC) are automatically ingested and used to update hydraulic simulations as conditions evolve. System outputs include time-dependent inundation extents, depths, velocities, and floodwave arrival times, providing actionable information to support emergency action planning, consequence assessment, and risk-informed decision making. This presentation describes the technical drivers for the system, the underlying modeling framework and data integration, and the flood hazard products developed to support dam and levee safety operations.