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Native Aquatic Species of the Gila River Basin
in Arizona and New Mexico

Drop Fish Barriers

Natural Fish Barrier - Fossil Creek A basic design for a drop barrier consists of a vertical concrete wall that rises 4-5 feet above a concrete apron on the channel bottom (Figure 1). The crest wall typically follows the configuration of the channel bottom so that a 4-5 foot drop extends across the entire channel bottom (Figure 2). The apron is designed to produce uniform water velocities that exceed fish swimming abilities, thereby precluding upstream passage. The vertical height of the barrier exceeds the leaping abilities of fishes when combined with the shallow, fast-flowing water over the apron. At high discharges, effectiveness of the vertical barrier will be lost in the center of the channel as water depths increase, but the vertical drop will be maintained at the edges of the floodwaters where current velocities are lowest. Upstream movements of fishes during floods are not expected in mid-channel because of high current velocities and sediment loads, but potential movements along the edges of floodwaters will be prevented by the maintained vertical drop.

Figure1.  Conceptual View of a Fish Barrier
Figure 1. Conceptual View of a Fish Barrier
(Click on the Diagram above for full size version - .JNG approx. 43 kb)

Figure 2. Plan View of Fish Barrier
Figure 2. Plan View of a Fish Barrier
(Click on the Diagram above for full size version - .JNG approx. 43 kb)


Constructed barrier sites                        Primary purposes
Aravaipa Creek Protect existing populations of spikedace and loach minnow
Cottonwood Spring Protect existing population of Gila topminnow
Fossil Creek Replicate Verde River population of spikedace, replicate undetermined population of loach minnow
Tule Creek Protect existing population of Gila topminnow
Bonita Creek Protect existing population of Gila chub, replicate Eagle Creek populations of spikedace and loach minnow
Hot Springs Canyon Protect existing population of Gila chub, replicate Aravaipa Creek populations of spikedace and loach minnow



Proposed barrier sites                      Primary purposes
Blue River Protect existing population of loach minnow, replicate Eagle Creek population of spikedace
O'Donnell Canyon Protect existing population of Gila chub, replicate undetermined population of Gila topminnow
Redfield Canyon Protect existing population of Gila chub, replicate Aravaipa Creek populations of spikedace and loach minnow
Redrock Canyon Protect existing population of Gila topminnow
Sheehy Spring Protect existing population of Gila chub, replicate undetermined population of Gila topminnow
Sonoita Creek Protect existing population of Gila topminnow
Tonto Creek drainage (stream not yet selected) Protect existing population of Gila chub, replicate East Fork White River population of loach minnow
Verde River Protect existing population of spikedace, replicate Aravaipa Creek population of loach minnow.


Reports:

Effectiveness of the Barrier-and-Renovate Approach to Recovery of Warmwater Native Fishes in the Gila River Basin


Last Reviewed:
November 29, 2011

Webmaster:
Joseph J. Billerbeck - jbillerbeck@usbr.gov