Ralph L. Parshall (1881-1959) is one of the most celebrated internationally-known alumni and faculty members in the history of Colorado State University. A pioneer in the fields of civil engineering and hydrology, Parshall is best known for developing the Parshall Flume at the then-named Colorado Agricultural College's hydrology lab in 1921. Noticing problems with stream flow measurements, Parshall developed the 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 obtain more accurate measurements of water flow.
This exhibit depicts events in Parshall's long and productive association with what is now Colorado State University. From his start as a freshman in 1899 to his appointment to the faculty, development of the flume and subsequent honors from the College, Ralph Parshall's career at the college is traced through photos and personal objects, highlighting the remarkable successes that have served to make Parshall such a recognized and remarkable alumnus.
Learn more through the Ralph L. Parshall Collection in the Water Resources Archive and materials digitized from the collection. Additionally, the Irrigation Research Papers contains materials (some digitized) from Parshall's team at the U.S. Department of Agriculture.
A freshman at Colorado Agricultural College (now Colorado State University) in 1899, a young Ralph Parshall (#9) starts his long and celebrated association with the school.
(From Historical Photographs, Archives and Special Collections, CSU)
Freshman Class, 1899 (closeup, Ralph Parshall labeled #9).
(From Historical Photographs, Archives and Special Collections, CSU)
After graduating from CAC in 1904 and pursuing post-graduate studies at the University of Chicago, Parshall joined the CAC faculty in 1907. When, after six years as CAC faculty, he joined the Irrigation Investigation Office of the U.S. Department of Agriculture, he continued to work at the college's hydraulics lab. 1925 faculty photo (Parshall is in the back row, third from right).
(From Historical Photographs, Archives and Special Collections, CSU)
Noticing problems with stream flow measurements, Parshall developed the Parshall flume to better measure such flows. The flume, when placed in a channel, measures the flow of the water as it uniquely relates to water depth. Ralph Parshall, taking flume measurements.
(Copyright ©1946 CSU/Photography and Digital Imaging)
A patent for "Venturi-flume water-stage recording instruments" was filed in 1921 and granted in 1922. See the full patent no. 1417941 online. Note that this was not for the flume, but for a recording instrument accompanying the main device.
(From Parshall Collection, Water Resources Archive, CSU)
In 1930, the Special Committee on Irrigation Hydraulics of the American Society of Civil Engineers decided to name what Parshall had been calling the improved Venturi flume for him. Though Parshall himself objected, others very much supported the renaming, including college president Charles Lory. See this and additional letters online.
(From Parshall Collection, Water Resources Archive, CSU)
In 1942, Parshall was honored by Colorado State College for his professional achievements in engineering and hydrology, as well as his assistance in designing the college's first hydraulics lab. Plaque of Achievement from the College.
(From Parshall Collection, Water Resources Archive, CSU)
Ralph Parshall is remembered not only for his success in hydrology and engineering, but also as one of Colorado State University's most celebrated alumni and faculty. His flume continues to be widely used in fixed flow monitoring, particularly in irrigation and sewage water measurements. At CSU, the hydraulics lab which Parshall helped develop is still thriving, ensuring his legacy and maintaining the university's reputation as a quality water research center.
(From Parshall Collection, Water Resources Archive, CSU)
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