Time Machine Tuesday: The Parshall Flume

Water is a precious resource in Colorado, so its use and conservation have been extensively studied by scientists throughout Colorado history. One of the best known scientists to study Colorado water was Ralph Parshall, who developed the Parshall Flume.

The Parshall Flume is “a device that, when placed in a channel, measures the flow of the water as it uniquely relates to water depth. Today, the Parshall Flume is still widely used to help gain more accurate measurements of water flow,” according to information in Colorado State University’s Water Resources Archive. Parshall conducted much of his hydrology research as a member of CSU’s faculty in the first half of the 20th century. The Water Resources Archive has created an online exhibit about Parshall and the development of his flume. Items in the exhibit include photos, drawings, and patents.

Parshall developed his flume as a modification of the Venturi Flume. In the 1920s, ’30s, and ’40s Parshall authored several publications about the flumes and their development. These publications have been digitized and are available online from our library:

• The Venturi Flume (1921)
• The Improved Venturi Flume (1928)
• The Parshall Measuring Flume (1936)
  
• Improving the Distribution of Water to Farmers by Use of the Parshall Measuring Flume (1945)

Parshall Flumes are still in use today. See the State Engineer’s Office’s publication Parshall Flume: Instructions for Installation and Table of Discharge for more current technical information.