The U.S. Bureau of Reclamation released a draft plan Wednesday responding to the invasion of nonnative, predatory fish in the Colorado River below Glen Canyon Dam. KNAU’s Melissa Sevigny reports.
Smallmouth bass began passing through Glen Canyon Dam in 2022 due to the low level of Lake Powell after years of drought. They’re exotic, predatory fish and according to the USBR pose an “unacceptable risk” to threatened and endangered species in the river such as humpback chub.
The plan examines options for dam management to reduce the numbers of nonnative fish. Among those are “cold shocks” in which cold water is released to lower the river’s temperature and disrupt spawning.
The document also discusses options for doing high-flow releases in the springtime to help rebuild Grand Canyon sandbars. These beach-building floods usually occur in the fall, but have been canceled in recent years in part due to worries about flushing smallmouth bass downriver.
The draft plan will be available for public comment for the next 45 days.
For more about upcoming virtual public meetings and how to comment on the plan: https://www.usbr.gov/uc/progact/amp/index.html
