Planning & Management

Oral

394465 - Balancing flood risk and water supply in California: Policy search combining short-term forecast ensembles and groundwater recharge

Wednesday, June 6
10:30 AM - 12:00 PM
Location: Northstar B
Co-Authors: Scott Steinschneider, Ithaca, NY – Cornell University; Munir Nayak, Ithaca, NY – Cornell University

Short-term weather forecasts are not codified into the operating policies of federal, multi-purpose reservoirs, despite their potential to improve service provision. This is particularly true for facilities that provide flood protection and water supply, since the potential flood damages are often too severe to accept the risk of inaccurate forecasts. Instead, operators must maintain empty storage capacity to mitigate flood risk, even if the system is currently in drought, as occurred in California from 2012-2016. This study investigates the potential for forecast-informed operating rules to improve water supply efficiency while maintaining flood protection, combining state-of-the-art weather hindcasts with a novel tree-based policy optimization framework. We hypothesize that forecasts need only accurately predict the occurrence of a storm, rather than its intensity, to be effective in regions like California where wintertime, synoptic-scale storms dominate the flood regime. We also investigate the potential for downstream groundwater injection to improve the utility of forecasts. These hypotheses are tested in a case study of Folsom Reservoir on the American River. Because available weather hindcasts are relatively short (10-20 years), we propose a new statistical framework to develop synthetic forecasts to assess the risk associated with inaccurate forecasts. The efficiency of operating policies is tested across a range of scenarios that include varying forecast skill and additional groundwater pumping capacity. Results suggest that the combined use of groundwater storage and short-term weather forecasts can substantially improve the tradeoff between water supply and flood control objectives for large, multi-purpose reservoirs in California.

Send Email for Jonathan Herman


Assets

394465 - Balancing flood risk and water supply in California: Policy search combining short-term forecast ensembles and groundwater recharge



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for Balancing flood risk and water supply in California: Policy search combining short-term forecast ensembles and groundwater recharge