The Bureau of Reclamation is seeking public comment on the draft Glen Canyon Dam/Smallmouth Bass Flow Options Environmental Assessment that presents four potential operational flow options aimed at preventing smallmouth bass from successfully spawning and establishing downstream of Glen Canyon Dam. 

Water levels in Lake Powell continue to decline to historically low levels, which has contributed to water being released at record high temperatures through Glen Canyon Dam. Below the dam, these warmwater releases are creating ideal spawning conditions for smallmouth bass, a predatory invasive fish species. 

To respond to the threat of smallmouth bass establishment below Glen Canyon Dam, the draft EA identifies various Glen Canyon Dam flow options designed to disrupt and prevent smallmouth bass from spawning in the Colorado River between the dam and confluence of the Little Colorado River. Reductions in water temperature combined with changes in flow velocity would be used to try and prevent smallmouth bass from successfully spawning and establishing downstream of the dam.The draft environmental assessment is available online at https://www.usbr.gov/uc/DocLibrary/EnvironmentalAssessments/20230200-GCDSmallmouthBassFlowOps_Draft EA_508.pdf. Reclamation will consider all comments received by March 10. Submit comments to gcd_smb_ea@usbr.gov. 

Glen Canyon Dam Adaptive Management Program

Original source can be found here