Nothing is more elegant and simple than a Parshall
Flume. The concrete or sheet metal devices, when properly built,
measure how much water flows through a ditch. While water courts
adjudicate, it is Parshall Flumes that actually measure out the
water. Unfortunately, they’re unlikely to do an accurate job.
According to Colorado State University, only 39 out of 149 flumes
an academic team examined in Colorado were in good condition, and
most of those were less than 10 years old. Because of settling, but
also due to corrosion, holes and vegetation, some flumes were as
much as 30 percent off. The obvious cure is to tear out the
offending flume, stabilize the ground, and put in a new one. But
Steven Abt, the civil engineering professor who led the study, has
developed a computer program that allows landowners to correct
water-flow measurements without replacing the flume. For
information about the Parshall Flume Discharge Correction Program,
contact Professor Abt, Civil Engineering, A227 Engineering Research
Center, Colorado State University, Fort Collins, CO 80523
(970/491-8203).
This article appeared in the print edition of the magazine with the headline Partial measurements.
Republish our articles for free, online or in print, under a Creative Commons license.
