Field‐Based Evaluations of Horizontal Flat‐Plate Fish Screens, II: Testing of a Unique Off‐Stream Channel Device—the Farmers Screen

Abstract

Screens are installed at water diversion sites to reduce entrainment of fish. Recently, the Farmers Irrigation District (Oregon) developed a unique flat‐plate screen (the “Farmers Screen”) that operates passively and may offer reduced installation and operating costs. To evaluate the effectiveness of this screen on fish, we conducted two separate field experiments. First, juvenile coho salmon Oncorhynchus kisutch were released over a working version of this screen under a range of inflows (0.02–0.42 m3/s) and diversion flows (0.02–0.34 m3/s) at different water depths. Mean approach velocities ranged from 0 to 5 cm/s and sweeping velocities ranged from 36 to 178 cm/s. Water depths over the screen surface ranged from 1 to 25 cm and were directly related to inflow. Passage of fish over the screen under these conditions did not severely injure them or cause delayed mortality, and no fish were observed becoming impinged on the screen surface. Second, juvenile coho salmon and steelhead O. mykiss were released at the upstream end of a 34‐m flume and allowed to volitionally move downstream and pass over a 3.5‐m section of the Farmers Screen to determine whether fish would refuse to pass over the screen after encountering its leading edge. For coho salmon, 75–95% of the fish passed over the screen within 5 min and 82–98% passed within 20 min, depending on hydraulic conditions. For steelhead, 47–90% of the fish passed over the screen within 5 min and 79–95% passed within 20 min. Our results indicate that when operated within its design criteria, the Farmers Screen provides safe and efficient downstream passage of juvenile salmonids under a variety of hydraulic conditions.Received November 17, 2011; accepted March 15, 2012

Evaluation of a fish-friendly self-cleaning horizontal irrigation screen using autonomous sensors

“…The results of this study reinforce the findings of Mesa et al (2012), who conducted an evaluation of a smaller (designed for a flow of 0.28 m 3 s À1 ; cf. 2.3 m 3 s À1 for the present study) Farmers Screen installed on Herman Creek at the Oxbow Fish Hatchery in Cascade Locks, Oregon.…”

“…2.3 m 3 s À1 for the present study) Farmers Screen installed on Herman Creek at the Oxbow Fish Hatchery in Cascade Locks, Oregon. Mesa et al (2012) used live juvenile coho salmon in two sizes ranges: small (54-78 mm) and large (85-145 mm). Mesa et al (2012) found that the overall rate of injuries was low; there were no severe injuries of eyes, fins or skin observed and there were no mortalities 24-48 h after passage over the screen.…”

“…Mesa et al (2012) used live juvenile coho salmon in two sizes ranges: small (54-78 mm) and large (85-145 mm). Mesa et al (2012) found that the overall rate of injuries was low; there were no severe injuries of eyes, fins or skin observed and there were no mortalities 24-48 h after passage over the screen. The injuries observed would not have exceeded the criteria established for safe passage of fish across conventional screen systems, which were established by the National Marine Fisheries Service (2008).…”

“…It was developed by Farmers Irrigation District in Oregon and designed to be installed in an off-stream channel where water, fish and debris pass quickly over the screen and return to the river or creek. Mesa et al (2012) evaluated a small version of the Farmers Screen using juvenile Coho salmon (Oncorhynchus kisutch) under a range of inflows (0.02-0.42 m 3 s À1 ) and diversion flows (0.02-0.34 m 3 s À1 ; the screen was designed for 0.28 m 3 s À1 ) at different water depths. Mesa et al (2012) reported that there was no injury or delayed mortality associated with the passage, and no fish were impinged on the screen surface.…”

“…Mesa et al (2012) evaluated a small version of the Farmers Screen using juvenile Coho salmon (Oncorhynchus kisutch) under a range of inflows (0.02-0.42 m 3 s À1 ) and diversion flows (0.02-0.34 m 3 s À1 ; the screen was designed for 0.28 m 3 s À1 ) at different water depths. Mesa et al (2012) reported that there was no injury or delayed mortality associated with the passage, and no fish were impinged on the screen surface. The Farmers Conservation Alliance (Hood River, OR, USA) has facilitated the construction of 48 Farmers Screens in seven states throughout the western US.…”