Each spring in the lower Provo River, adult June sucker (Chasmistes liorus) are observed spawning, and significant numbers of recently hatched larvae are subsequently monitored drifting downstream. But post-larval survival rates of June sucker have been found to be low to zero since the species was listed as endangered in 1986 (and before). Monitoring efforts have not documented the successful recruitment of wild June sucker from Provo River and research has shown that larval fish generally do not survive longer than about 20 days after hatching. It is believed that the larval fish die because of a lack of suitable “nursery” or rearing habitat and are therefore unable to recruit into the adult population. The Provo River Delta Restoration Project is proposed as an essential action needed to recover the June sucker, an endangered fish that occurs naturally only in Utah Lake. The project will restore functional habitat conditions in the lower Provo River and its interface with Utah Lake that are needed for spawning, hatching, larval transport, survival, rearing and recruitment of young June sucker so they can grow and become reproducing adults and be self-sustaining.
Under Alternative B, the majority of the river’s flow will be directed north into a new river channel where braided channels and oxbow wetland features will be created to provide the needed aquatic habitat larval June sucker need to survive. The flow will continue into Utah Lake to the north of Utah Lake State Park. Currently, the river meets Utah Lake to the south of the State Park. With Option 2, the existing Provo River channel will remain in place as a recreational feature (approximately the last 2 miles of the river before it enters Utah Lake). A small portion of the Provo River’s flow will remain in the existing the channel and a small dam will be constructed at the downstream end of the existing channel, near Utah Lake State Park. The dam will serve to maintain a relatively constant water elevation in the channel year-round. An aeration system will also be installed in the channel to improve water quality over what currently occurs, particularly in summer months.
Continued management and future use of Provo River water is closely tied to recovery of the June sucker. June sucker recovery will reduce risks to water supply reliability and result in an improved ecosystem for all who use the Provo River and Utah Lake.