| Project title: | Fish Passage for Small Diversion Dams |
| Project researchers: | Brent Mefford and Charles Liston |
| Project ID: | ER.4 |
| Duration of project: | FY96-FY98 |
Research Problem and Background:
During its history, the Bureau of Reclamation has designed and constructed a large number of small irrigation diversion dams throughout the Western United States. Most of these diversion dams are on rivers that are home to mainly non-game fish species. Thus, little attention has been focused on the fishery impacts imposed by these barriers. Many of these diversion dams are approaching 100 years of age and only now are the detrimental impacts small dams have on many native fish species being realized. Recent declines of native western fish species have resulted in numerous listings of species as threatened or endangered under State and Federal laws. During the past 100 years, some 21 species and sub-species among 6 fish families have become extinct in the 17 Western States, and some 64 species and sub-species are now threatened or endangered. Although not wholly responsible for the decline, barriers to habitat and spawning migration are known contributors. The research study focuses on the design of fish passes for non-salmonid fish that are indigenous to rivers in the Western United States. Experience has shown us that standard designs of fish ladders developed for salmon are often poorly suited for other native species.
| menu |
Project Objectives:
The objective of the project was to use a combination of laboratory and field studies with the goal of developing better designs and guidelines for incorporating fish passage for existing diversion dams. Both structural and riprap channel forms of fish passes will be studied. The main parameters of the study will be identifying passage efficiency as a function of fish pass slope, bottom roughness, and large-scale flow turbulence.
| menu |
Overall Outcome or Conclusions:
Numerous new fish pass concepts have been tested in a laboratory flume. The focus of the research has evolved with the development of a new design concept that merges low gradient pool and riffle concept with that of a steeper gradient baffled ladder. New designs that have been investigated include the use of rock barbs to create a continuously baffled channel without weirs. The design provides a low velocity path along the channel invert coupled with higher skimming or surface flow. Flume tests show velocities of about 2.0 ft/s can be maintained for a channel slope up to 4 percent (the steepest slope tested thus far). The design can be built in a riprap- or concrete-lined channel. The design provides low velocity resting areas but does not generate large reverse flow eddies that disorient fish. The design is particularly well suited to bottom-oriented native species of the western rivers.
Tests of several styles of natural channel-type passages were also conducted. Chevron rock weirs proved to be very effective at channel slopes of 4 and 5 percent. Hydraulic data and fish runs were conducted for each design. Tests were conducted with juvenile trout (<2 inches) and young razorback suckers (4-6 inches). The movement of the fish through the ladders was monitored and video taped. This data was used to identify flow field preferences displayed by different species. These tests identify the importance of the velocity boundary layer created by large-scale bottom roughness for passing bottom-orientated fish and weaker swimming juvenile fish. Razorback suckers and juvenile trout were able to hold position and move upstream better with riprap-lined channel invert verses a smooth surface of the type commonly found in concrete flume fishways. This is an important consideration in the selection and design of fish pass structures. Young razorback suckers were found to move upstream through both the riprap weir and the alternating barb-style ladder designs at channel slopes of 4 to 5 percent. The alternating barb design appeared to provide the best passage.
Tests were also conducted of conventional style weir and orifice, vertical slot, and Denil fishpasses set at slopes of 5 percent and flatter. Each of these designs showed greater disorientation for bottom-oriented fish species with the ladders than with the roughened channel designs.
Overall outcome or conclusions:
To date, the research results have been used to improve the design and efficiency of several fish pass structures to date. A fish lock, fish ladder, and gradient restoration rock ramp (under construction) were constructed at Marble Bluff Dam, near Reno, Nevada, to pass endangered cui-ui lake suckers and threatened Lahontan cutthrout trout up the Truckee River. In 1998, using the new facilities, about one-half million adult cui-ui were passed over Marble Bluff Dam. On the Colorado River, a design riffle was constructed in 1998 to enhance passage of a small irrigation dam owned by the Grand Valley Irrigation Company. The dam is one of several small dams that have been identified as a barrier to endangered razorback suckers, Colorado squawfish, and many other fish species native to the river. Other fish passes are currently in the feasibility design phase for the Yellowstone River in Montana, Link River in Oregon, and San Juan River in Colorado. In each of these cases, non-salmonids are the target species being addressed.
| menu |
Partners
The major projects that provided assistance to the research were:
Marble Bluff Dam fish passage on the Truckee River - Lahonton Area Office; USFWS, Reno Nevada; Pyramid Lake Fisheries; and Northern Nevada Nature Conservancy.
Lower Yellowstone River fish passage enhancement project - Montana Area Office; USFWS, Billings, Montana; Montana Division of Fish Wildlife and Parks; Intake Irrigation District; and Huntly Irrigation District.
Colorado River Fish Passage, GVIC, and Price Stubb Dams - Grand Junction Area Office; USFWS in Grand Junction, Colorado; Colorado Department of Fish and Game; and the Grand Valley Irrigation Company
| menu |
Publications and/or Other Deliverables
REPORTS:
Bureau of Reclamation. 1998. Physical Model Study of Marble Bluff Dam Cui-ui Passage, Water Resources Research Laboratory, PAP-802.
Kubitschek, J., and B. Mefford. 1997. Grand Valley Irrigation Company Diversion Dam Fish Passage, Bureau of Reclamation Water Resources Research Laboratory, R-97-06.
Liston, C., P. Johnson, B. Mefford, and D. Robinson. 1996. Fish Passage and Protection Considerations for the Tongue River, Montana. Bureau of Reclamation Water Resources Research Laboratory, PAP- 692.
Mefford B. 1998. Fish Passage for Non-Salmonids. Bureau of Reclamation Water Resources Research Laboratory, Draft Report.
Mefford, B., T. Haider, R.Christensen, and C. Liston. 1996. Marble Bluff Dam - Fish Passage Study. Bureau of Reclamation Water Resources Research Laboratory, PAP-690.
TECHNICAL PAPERS:
Mefford B. 1997. Non-Salmonid Fish Passage for Small Diversion Dams. American Fisheries Society Annual Meeting.
Mefford B., and J. Kubitschek August 1997. Evaluating the Hydraulic Performance of Fish Passage Structures. In Proceedings 27 IAHR Congress.
(The Reclamation Fisheries Engineering Manual currently being written will also include much of the research results.)
| menu |