Better Redd than Dead: Optimizing Reservoir Operations for Wild Fish Survival During Drought

Abstract:

Extreme droughts are difficult to predict and may incur large economic and ecological costs. Dam operations in drought usually consider minimizing economic costs. However, dam operations also offer an opportunity to increase wild fish survival under difficult conditions. Here, we develop a probabilistic optimization approach to developing reservoir release schedules to maximize fish survival in regulated rivers. A case study applies the approach to wild Fall-run Chinook Salmon below Folsom Dam on California’s American River. Our results indicate that releasing more water early in the drought will, on average, save more wild fish over the long term.