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| Marie Dorian Dam Removal |
Umatilla County, Oregon |
Primary Project Type: Fish Passage
Secondary Type: |
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The North Fork and the South Fork of the Walla Walla River converge into the mai... |
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Primary Problem: Dams
Secondary Problem: |
| Main Restoration Action(s): Dam Removal |
| Native Fish Focus: Salmon, Steelhead |
Is this project part of a watershed scale restoration? No
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| Project Dates: April 1997 to April 1997 |
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Initial Monitoring:
Restoration Implementation:
Follow-up Monitoring: |
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Lead Agency:
Confederated Tribes of the Umatilla Indian Reservation
U.S. Army Corp of Engineers
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| Project Location:
The Walla Walla River originates on the slopes of the Blue Mountains, south and east of Walla Walla, Washington. The river flows 79 miles in a westerly direction to the Columbia River. The Basin is located in northeast Oregon and southeast Washington and has a drainage area of 1,758 square miles. The North Fork and the South Fork of the Walla Walla River converge into the main stem Walla Walla River not far from the city of Milton-Freewater in northeastern Oregon. The Marie Dorian Dam was located on the main stem between this confluence and Milton-Freewater. The Walla Walla River is a tributary to the Columbia River and it flows for over 55 miles.
For a map of the project area, click here.
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Project Description:
Historically, the Walla Walla River supported several populations of salmon species. Fall and spring chinook salmon were abundant in the basin, but over-appropriation of water and inadequate passage conditions has eliminated them from the basin. Spring chinook salmon have been experimentally reintroduced to the basin and steelhead, resident redband trout and mountain whitefish are still present in the basin in moderate numbers. Because hatchery steelhead have never been released in upper reaches of the Walla Walla river, the steelhead population is a genetically pure wild fish population. The South Fork Walla Walla and Mill Creek support healthy populations non-migratory bull trout; however, they are absent or in low abundance in other tributaries to the Walla Walla and they face extinction in this watershed due to genetic isolation. The salmonid habitat in the headwaters is in good to excellent condition and could support significantly more anadromous salmonids. Steelhead and bull trout are both listed as threatened under the Federal Endangered Species Act.
The original Marie Dorian Dam was constructed out of wooden splashboard for irrigation purposes in the 1880’s. In 1952 the dam was modified by the U.S. Army Corps of Engineers to an 8-foot high concrete structure for compatibility with levees being built at the time. The height of the dam and the fact that it spanned the entire 100-foot width of the Walla Walla River created strenuous conditions for adult summer steelhead to reach spawning habitat upstream, particularly during low flow conditions. Spawning fish would arrive in numbers at the dam. During higher flows, some would successfully jump the dam, but others would be poached or die from exhaustion at attempting to jump the dam. Juveniles were often stranded with no chance to move upstream to feeding and rearing habitat. The dam also isolated non-migratory bull trout populations from genetic mixing with populations in the upstream South Fork tributary. |
| Project Goals: The goal of the project was to remove the dam, which would open up 20 miles of migratory fish passage on the mainstem of the Walla Walla River and numerous other tributary miles for summer steelhead populations. Adult steelhead would have access to upstream spawning grounds. Juveniles would not get stranded at the dam, so they could reach feeding and rearing habitat. Dam removal would also allow genetic mixing for local bull trout populations by giving access to the South Fork tributary, an important gene pool. |
| Project Methods:
The removal of the Marie Dorian Dam, orchestrated by the Confederated Tribes of the Umatilla Reservation, involved the cooperation of federal, state, tribal, and local government agencies, non-profit environmental organizations and private landowners. Due to the concern of impact to adult Steelhead in the river, blasting the dam was not an option. Instead, removal was done using a track-hoe equipped with a large claw that chewed through the dam’s three-foot thick concrete walls.
Click here for more information on methods used.
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Due to potential impacts on adult steelhead in the river, blasting the dam was n... |
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Under emergency conditions, and loss of an expected funding source, seven agenci... |
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Monitoring Data and Collection
Methods: Monitoring efforts were not specific to salmonid response to the removal of Marie Dorian Dam. However, extensive monitoring is on-going in the 1,758 square mile Walla Walla River Basin under the Walla Walla Basin Natural Production Monitoring and Evaluation Project (WWNPME), funded by Bonneville Power Administration (BPA). Monitoring work conducted by the Fisheries Program of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) includes the following objectives:- Estimate abundance and densities of juvenile spring Chinook salmon, summer steelhead, bull trout and mountain whitefish.
- Estimate minimum survival and timing of outmigrants of juvenile Chinook and steelhead from the Walla Walla River to John Day Dam.
- Determine age and growth characteristics of natural anadromous salmonids.
- Determine natural spawning success, spawning habitat utilization, pre-spawning mortality, and redds per introduced adult spring Chinook salmon.
- Monitor stream temperatures.
- Collect baseline genetic data from Walla Walla River endemic summer steelhead.
- Monitor Adult steelhead and bull trout movements past potential migration impediments and throughout the Walla Walla River Basin with radio telemetry.
Click here for more information on monitoring.
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| Was this project effective
and how was this determined? Under emergency conditions, and loss of an expected funding source, over seven agencies and organizations came together with resources to provide a well for local irrigators affected by the partial breech of the dam and to safely remove the Marie Dorian Dam. The removal of the Marie Dorian Dam was significant in opening up over 20 miles of migratory fish passage on the mainstem Walla Walla River and numerous tributary miles. The removal also allows genetic mixing of federally threatened bull trout populations.
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(Before) The height of the 8-foot Marie Dorian Dam and the fact that it spanned ... |
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(After) The removal of the Marie Dorian Dam was significant in opening up over 2... |
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| Confounding Effects/Additional
Information: |
| Project
Specs (all specs are estimates): |
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| For more information on this project
contact: |
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Jed Volkman, Confederated Tribes of the Umatilla Reservation, Email: JedVolkman@ctuir.com
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| This information
was collected by: Kristin Keith |
| Project last updated on: 6/17/2005 |
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