These photos show that between 1965 and 1969, the original Mill Race was closed off just upstream from where Crystal Lake Drive then crossed, and a new channel was dug north across Evanite and then City land to a point on the Marys River just upstream of the confluence with the Willamette River. The new channel ran first NW toward a gap between two Evanite buildings resulting in a left-hand 90 degree turn. Twin 48" culverts, still in place, led under the railroad spur (see photos nelow), and an existing culvert (~20-30' diameter) carried water north under what was then called Chapman Place toward the Marys River. The smaller size of the new ditch, the 90 degree turn where the old channel connected to new, and the undersized culverts likely reduced flow significantly and led to increased flooding in South Corvallis.
Extensive review of both City and County records had failed to yield any records of local government involvement in the planning of this channel realignment. Finally, in 2015, a search of on-line City archives told the story.
City Council minutes for June 19, 1967, state that Evanite personnel met with the City Manager and unspecified staff members to discuss how the Mill Race could be modified to better drain floodwater from the South Corvallis area. Evanite’s interest was presumably prompted by its desire to fill in the Mill Race at its eastern end, to improve access to and around the hardboard plant. Evanite had stopped using their Mill Race water by 1958.
Council minutes for October 2nd state that Mill Race modifications had been made, and included “trespass … across City lands at the mouth of the Mary’s River.” The clear implication is that this was done without City approval or even further consultation. Note also that the minutes refer to use of an existing culvert under Chapman Lane (known at the time as Crystal Lake Drive).
The minutes for October 16, 1967, refer to a Public Works Department report of October 12th that stated that the realignment was indeed done without “consultation or approval of the City of Corvallis.” The City does not have a copy of this October 12th report. It appears, however, that no action was ever taken by the City or County against Evanite, despite clear evidence that the realignment significantly impeded drainage of flood waters from South Corvallis.
The City of Corvallis eventually rebuilt all the affected parts of the Mill Race, much of it at City expense, but the last stage of the work was not completed until 1997, presumably in response to the disastrous flood of 1996.