Provo River "Delta" update: rebuilt diversion, aeration systems and riverfront park work continue

Mike Mills, executive director of the Utah Reclamation, Mitigation and Conservation Commission, updated the Provo City Council work session on May 6 about remaining work on the Provo River original channel and the Delta restoration project.

Mills said the project team rebuilt a diversion structure intended to supply a minimum of 10 cubic feet per second (CFS) to the remaining channel; the new structure offers a wider opening that Mills said will be easier to maintain at both low and high flows. "We would be sending everything out to the Delta" under high lake conditions, Mills said, describing the plan to divert flows to the restored Delta when Utah Lake elevations make the original channel impractical to manage.

Mills described water-quality work including aeration systems installed in 2023 and extended downstream to improve dissolved-oxygen levels during warm months. He said aeration now reaches from the Center Street bridge area downstream to Utah Lake State Park and upstream to Alligator Park; the systems are intended to keep the channel oxygenated for fish and recreation.

Major project elements and status Mills described:

- Diversion and flow management: a rebuilt intake to deliver a committed minimum of 10 CFS to the original channel; the diversion can also be used to flush vegetation by releasing larger flows if needed. - Aeration and water quality: aeration infrastructure installed in 2023 and extended; prior monitoring (2012–13) showed temperature and dissolved-oxygen concerns during summer months, which the aeration aims to address. - Downstream water-check structure: a small downstream dam (check structure) at Utah Lake State Park to reduce water-level fluctuations in the original channel; the structure required extended settlement time and construction is planned to continue into July. - Recreation facilities: two nonmotorized boat-launch ramps (West Trailhead and Alligator Park), three fishing platforms near Lakeside RV and the West Trailhead, and fish stocking in coordination with the Division of Wildlife Resources. - Parks and trails: Delta Gateway Park (about four acres acquired and transferred to Provo City) is under construction and has playground and shade elements; an opening is targeted for June (Council staff discussed adding a June 25 date to the calendar). - Mosquito abatement and monitoring: additional mosquito-monitoring sites and funding were added; Utah County used supplemental funds in July 2024 and monitoring will continue. - Trail repaving: a planned repaving of the trail from Lakeshore Drive to Utah Lake State Park has been delayed and may be rescheduled for early 2026.

Mills addressed flooding risk at high Utah Lake elevations and explained that at historically high lake levels the management plan directs sending flows to the Delta; he noted the check structure is designed so the original channel can maintain approximately 6 inches of stability in water level for easier public access when the lake is not at high elevations. He said the dam preloading process required lengthy settlement, which concluded around November 2024, and construction crews will return to finish work.

On trees and vegetation, Mills said project contractors removed five trees to make room for boat ramps and that county staff identified a small number of additional trees near the trail that may need removal; he said preserving the trail’s shade canopy is a priority.

Mills invited council input on naming the original channel and described a working group with the city, county and the Division of Wildlife Resources to collect name suggestions; he also proposed public engagement (a poll on the Delta website or on-the-ground suggestion collection at the park opening).

Councilors asked technical questions about the diversion, lake elevations and floodplain behavior; Mills sought continued coordination as the project moves into finishing construction and park activation. No formal council action was taken during the update.