Tumalo Dam Hike

TumaloReservoirHike12 10Apr2017

Bull Flat from Tumalo dam

A brief history

It’s hard to imagine that the big flat area pictured above was once filled with water that all disappeared. Developer William A. Laidlaw was in this area in the early 1900’s and he promised settlers a project that would irrigate nearly 30,000 acres. Local businesses and settlers put up some of their hard earned dollars for the project but then figured out they were being taken advantage of. Laidlaw was burned in effigy in 1907 and 1912. New plans were made by the state for a reservoir.

Construction of the dam ca. 1914

Tumalo Dam construction.  Photographic copy of TID photograph (from original print on file at TID office, Tumalo, Oregon).

In 1914, the huge earthen Tumalo Dam on the edge of 1,100 acre Bull Flat was constructed. It took 18 months to complete. The reservoir was filled with thousands of gallons of water. A couple of school kids were passing by the reservoir one day and heard a roaring noise like a tub draining. A giant whirlpool was sucking down the water at the rate of 220 cfs – as fast as it was being filled. Yikes!

They tried plugging the hole with bales of hay and detonating dynamite on floating barges. Nothing worked. It turned out the engineer that designed the project had not done much work on the soil at the site. It is extremely porous and modern day engineers liken it to a sponge. There are also lava tubes underneath the surface.  Continue reading