Recovering the Threatened June Sucker

 
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The Provo River Delta Restoration Project

Project Features

The purpose of the Provo River Delta Restoration Project is to help recover the threatened June sucker, and in doing so, restore the area’s natural ecosystem. The project will provide and improve recreational experiences in and around the original lower Provo River and the newly restored delta. By building this project, partners in the June Sucker Recovery Implementation Program help ensure important water projects linked to June sucker recovery stay on track. The diversity of habitats and function supported by the delta area will provide the necessary conditions for juvenile June sucker to develop to a size where they can survive in Utah Lake. 

The delta project officially broke ground on June 11, 2020 and the next three years were mostly spent excavating a system of braided channels and wetland ponds in 260 acres of acquired agricultural land just north of the original Provo River channel. Major revegetation efforts followed construction each fall, with stewardship activities taking place throughout the year to cultivate and protect plantings. 

In 2022, the northern end of Skipper Bay dike - which was initially constructed in the 1940s to hold Utah Lake out of the area - was lowered and four outlet channels were constructed through the lowered dike. This reconnected the lake with historic Skipper Bay, allowing Utah Lake to expand eastward toward its historic shoreline. On March 2, 2023, the Provo River was diverted from a point just downstream of Lakeshore Bridge into the newly constructed delta. The river eventually made its way through the delta and new outlet channels into Utah Lake over the next week.

In the first June sucker spawning event after the river was diverted, a near record number of June suckers migrated through the new delta into the Provo River. Nearly 6,300 tagged June suckers were detected entering the delta, from April 1st through July 12th.  Incredibly, because only a small portion of adult June sucker are tagged, the total number that entered the delta is likely 5 to 10 times greater.

 Recreation Facilities

Project construction in 2024 is focused on completing planned recreation, access, and water level management features along the original Provo River and in and around the delta. The original lower Provo River channel will continue to receive a guaranteed portion of Provo River flow through a constructed diversion facility. A small dam being constructed at the channel’s downstream end, near Utah Lake, will maintain water levels to support recreation through this reach. Currently the small downstream dam has been “pre-loaded” with materials to consolidate soft soils and stabilize the structure’s foundation. The structure must be left alone to settle for up to one year before it can be completed in 2025.

Recreation facilities to be constructed include new trailhead and parking areas, horse-trailer parking and path, non-motorized boat ramps, restrooms, river access, fishing platforms, interpretive features, and a viewing tower. Trails that will provide connections between Utah Lake State Park, the delta, and the existing Provo River Parkway Trail will be constructed. In addition, Provo City will be developing the Delta Gateway Park, which will include a nature focused playground and will be a significant hub for the community into the future. 

Project Construction Schedule

 

Restoring June Sucker Nursery Habitat

Is Essential to Recovering the Species

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History

Historically, a broad delta and floodplain (vegetated with emergent marsh wetlands, oxbow wetlands, wet meadows, cottonwood and willow dominated riparian areas, etc.) existed at the lower Provo River/Utah Lake interface. With human settlement, the Provo River was confined to a narrow channel behind levees. Levees confined spring flood flows of the Provo River to a single channel and allowed for agricultural production and settlement but greatly reduced habitat value for fish and other aquatic life.

Research of conditions prior to the delta project showed that almost all June sucker died after about 20 days from hatching because the lower reaches of Utah Lake tributaries lacked the physical habitat, food production, appropriate temperatures, and water quality conditions necessary to support the growth and survival of young June sucker. Additionally, the majority of Utah Lake lacks vegetative cover necessary for young June suckers to escape from predators.

The U.S. Fish and Wildlife Service listed the June sucker as endangered with critical habitat in 1986. The species had a documented wild population of fewer than 1,000 individuals at the time of listing. In 1987, the wild spawning population was estimated to be between 311 and 515 individuals. In February 2021, about a year after the delta restoration project began, the U.S. Fish and Wildlife Service officially reclassified the June sucker as a threatened species.

A healthy functioning river-lake interface, or delta ecosystem, is characterized by a meandering channel across a broad floodplain. As a river approaches a body of water (a lake or ocean), it slows down and bedload and suspended sediments drop out of the river flow. As these sediments accumulate over time, the river begins to braid into a series of distributary channels. Sediment accumulation causes the threaded channels to shift position over time, providing a diversity of habitat types including shallow and warmer areas off the main channel, and features such as abandoned channels, backwaters, and oxbow wetlands. These off-channel areas provide food resources for larval fish as well as refuge from predatory fish. In the case of historic Utah Lake tributaries, these off-channel habitat zones would have been critical to June sucker survival and recruitment to more developed life stages.

The Provo River Delta Restoration Project will mimic these historic hydrologic features in which June sucker evolved by creating distributary channels with a diversity of delta habitat.