The Jim Hinkle Spring River State Fish Hatchery near Mammoth Spring, Arkansas, is one of the largest state-owned trout-producing facilities in the southeastern United States. Built in 1974, the hatchery annually produces 650,000 to 800,000 rainbow trout for stocking streams across southern Arkansas. Water for the gravity-fed hatchery comes from the Spring River at a rate of about 70,000 gpm, flowing to the hatchery’s 56 tanks, 21 linear raceways, 11 round fiberglass silos and 24 round concrete silos.

Challenge: Maintaining debris-free flow

Trout require clean, moving water to thrive. Removing debris before river water enters the hatchery is critical to maintain water flow. The freshwater intake at the facility has a high volume of vegetation that can decrease flow, posing a threat to fish survival.

To remove debris, the hatchery was using an aging screening device that required constant maintenance. During heavy rain, cleaning the screens was an all-hands-on-deck event requiring manual debris removal to keep water flowing to the hatchery. In extreme events, the screens would have to be removed, leaving only the inlet bar grate to prevent a debris overload. Afterward, workers in diving equipment had to clean out muck, vegetation and debris for days.

Solution: Duperon Harvest Rake 

In 2023, the hatchery replaced the aging manual screens with two Duperon Harvest Rake screens. The Harvest Rakes collect debris upstream from the hatchery and deposit it on a conveyor belt, automatically returning it to the river downstream. This keeps the hatchery debris-free while minimizing impact on the natural flow of the river and dramatically reducing labor requirements. 

Designed to manage high volumes of aquatic vegetation, the Harvest Rake is ideal for sites that have side currents, backflow or channel turbulence. The unit can be adjusted for large debris and above-average flow conditions. The installation at Jim Hinkle includes a rear spray bar that ensures the conveyer is always clear and ready to accept debris from the rake.

The Arkansas Game and Fish Commission requires equipment that does not disrupt the wildlife upstream or downstream of the hatchery or expose wildlife to hazardous chemicals. The Duperon Harvest Rake met all environmental requirements.

Proving its worth

On July 13, 2023, a major rain event caused a 3-foot rise in the Spring River in just three hours. With the old screens, this would have required calling in at least two workers for all night flood duty to manually remove debris, followed by days spent cleaning the screens to regain optimal flow.

The flood was no match for the Harvest Rake, which easily and reliably removed large amounts of debris from the screens. River water continued flowing safely into the hatchery with no manual intervention.

“With the Harvest Rake, the screening of the river is no longer something I have to worry about,” Hatchery Manager B.J. Vandiver says. “I don’t worry about it getting clogged up, I don’t worry about a large log damaging it, and I don’t worry about losing fish during a heavy rain.”