The Brownsville Dam Project

 

 

Story of the Brownsville Dam

The Brownsville Dam was originally built as a diversion dam in the late 1880s to divert water into a millrace (the Brownsville Canal) that brought water to Brownsville woolen, flour, and timber mills. The wooden crib dam fell into disrepair and disuse by the 1940s when the mills closed and the structure blew out during a flood.  The dam was rebuilt in 1967-68 by the local Soil Conservation Service who received federal dollars from the Community Beautification Act. However, it no longer served a need; no commerce, flood control, or community water supply were provided by the dam. Instead, it continued to deliver water into the Brownsville Canal at a rate of 2.5 cfs (cubic feet per second) to meet the City of Brownsville’s 1992 water right. Today, the Brownsville Canal continues to flow through town and the backyards of many residents and is an important aesthetic feature.

 

Reaching a Decision: Removal of the Brownsville Dam

                                                                

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The removal was made possible by technical support and funding from numerous partners and especially because of countless volunteer hours from the watershed council and Brownsville community.  The Brownsville Canal Company and local residents had mixed feelings about the dam removal. Some were sad to lose this part of local history, but others appreciate the fact that a pump station will be installed Summer 2008 to continue the flow of water into the Brownsville Canal for watering livestock and pastures.

 

For a final report on dam removal from Cascade Earth Sciences, click here.

 

Monitoring after dam removal

Physical and biological conditions

Project engineers expect it will take one or two years for the Calapooia River to re-establish the natural channel and distribute the gravel that has accumulated behind the structure. The Council will be working with Oregon State University researchers to monitor physical and biological conditions of the Calapooia River after dam removal.

Before the Brownsville Dam was removed, these researchers surveyed the topography and river channel above the dam, characterized gravel size, calculated the volume of sediment behind the dam, and sampled macroinvertebrates. Since the removal of the dam, Dr. Desiree Tullos and her graduate students have been making continuous temperature and sediment discharge observations, resurveying the channel above the historic site of the dam, and continuing to sample macroinvertebrates. They have been making observations related to the hydrologic and morphologic characteristics of the river, and interactions among flow and sediment transport. They are also  studying the responses of aquatic and streamside habitats. For more information, visit OSU’s website.

 

Socioeconomic conditions

Oregon State University researchers are also investigating the social and economic impacts of the Brownsville dam removal on the community. Because social impact assessments on small dam removal are minimal, researchers will use this project to design a template that includes socio-economic indicators that can be applied to other similar dam removal projects.

Calapooia Watershed Council

The Calapooia Watershed Council worked with the City of Brownsville and community residents for several years to reach the decision to remove the Brownsville Dam in 2007. Since its construction, the dam (located at river mile 36) had blocked fish access to the best salmonid spawning and rearing habitat in the Calapooia Watershed (current spawning and rearing habitat occurs above river mile 50). Affected fish included cutthroat trout, Pacific lamprey, winter steelhead and spring Chinook salmon. This fish passage barrier became even more of a concern when spring Chinook and winter steelhead were listed as “threatened” on the federal Endangered Species Act in 1999. The Calapooia Watershed steelhead represent the uppermost distribution of steelhead in the Willamette system.

A dam breaching event was held on August 27th, 2007 at the site. Speakers at the event included representatives of local, state and federal organizations involved in the project. Partners included the Calapooia Watershed Council (CWC), NOAA Fisheries, Oregon Department of Fish and Wildlife, Oregon Water Resources Department, US Forest Service, Linn County Road Department, City of Brownsville, Brownsville Canal Company, and Oregon Watershed Enhancement Board.