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Irrigation Research Papers

Identifier: WIRP

Scope and Contents

The Irrigation Research Papers consists of documents dated from 1890 to 1985, with the bulk falling from 1920 to 1950. The collection documents the development of irrigation equipment, practices, and knowledge in the early twentieth century. It captures the activities of the researchers, working methods, and unpublished knowledge. The geographic focus of the collection is Colorado, especially the Cache la Poudre River Basin, but also includes California, Wyoming, Arizona, Idaho, Texas, North Dakota, and Nebraska. Correspondence exchanged with ditch companies about research and experiments reveals the interests of practicing irrigators. The collection also includes meeting minutes and conference materials from professional organizations such as the American Society of Civil Engineers, the Association of Western State Engineers, and the Western Irrigation and Drainage Research Association. Some of the materials document the beginnings of these and other conferences. The collection also documents groundwater research and the early days of snow surveying and runoff forecasting for western states. The photographic portion extensively depicts irrigation-related equipment and practices, both in the field and in the laboratory, but most of the images are not labeled or dated. The collection includes correspondence, scientific data, research notes, drafts, finished articles and reports, speeches, receipts, invoices, blueprints, drawings, maps, photographs, and negatives.


  • Creation: 1890-1985
  • Creation: Majority of material found within 1920-1950

Restrictions on Access

There are no access restrictions on this collection.

Restrictions on Use

Not all of the material in the collection is in the public domain. Researchers are responsible for addressing copyright issues.


The Irrigation Research Papers originated with early twentieth century scientists in the United States Department of Agriculture (USDA) Irrigation Investigations Unit. Undergoing several name changes to become today's Water Management Research Unit, the Irrigation Investigations Unit has a legacy of significant researchers and achievements.

In 1911, the Irrigation Investigations Unit was established at Colorado Agricultural College (now Colorado State University) in Fort Collins, with Victor M. Cone as its first director. Cone's work largely focused on measuring water flows and the design of canals and diversion structures.

In 1913, Ralph Parshall was appointed director of irrigation investigations in the USDA's Irrigation Investigations Division. During his time in charge, Parshall oversaw and conducted research on irrigation methods in the western United States. While his most notable work was the invention of the improved Venturi flume, later renamed the Parshall flume, Parshall also designed and built other water measurement instruments and meters, studied groundwater, and conducted snow surveys. Carl Rohwer joined Parshall in 1914. Together they studied evapotranspiration, water flow measurement, well designs, and ditch seepage.

In 1915, the USDA reorganized so all agricultural engineering work would fall under the same supervision. The Irrigation Investigations Division was transferred to the newly formed Office of Public Roads and Rural Engineering, which in 1918 became the Bureau of Public Roads. Within the Bureau of Public Roads, the Division of Agricultural Engineering oversaw the Division of Irrigation.

On July 1, 1931, the USDA again reorganized and the Division of Agricultural Engineering became the Bureau of Agricultural Engineering. The irrigation staff continued to carry out their experiments and research when, on July 1, 1939, they became part of the Soil Conservation Service. Finally, in 1953, the Agricultural Research Service was formed with the Division of Irrigation and Water Conservation joining the Soil and Water Conservation Research Branch and eventually becoming the Water Management Research Unit.

Following Parshall's retirement in 1948, Rohwer led the group until his own retirement in 1956. The work of these and other men furthered the understanding of irrigation methods, equipment, and techniques in the first half of the twentieth century.


29.75 linear feet (47 document boxes, 9 photo boxes, 7 negative boxes)

Language of Materials



In 1911, the Irrigation Investigations Unit of the U.S. Department of Agriculture was established in Fort Collins in conjunction with Colorado Agricultural College (now Colorado State University). Scientists within the unit, including Ralph Parshall, Carl Rohwer, Victor M. Cone, and William E. Code, conducted irrigation-related research. They studied and designed apparatuses to measure water flow through canals and diversion structures, investigated various irrigation projects, and conducted snow surveys. Materials include letters, data, field books, drafts, reports, blueprints, maps, conference materials, photographs, and negatives. A portion of the collection is digitized and online.


Most of the original envelopes of both papers and photographic materials were numbered by the collection creators. This original order was largely retained.

The collection consists of 2 series in 63 boxes:

Series 1: Papers, 1890-1985 and undated

Series 2: Photographs, 1903-1955 and undated

Custodial History

In November 1987, the archivist at the Colorado State University Libraries arranged for the Irrigation Research Papers to be stored at the Colorado State Archives in Denver. In September 2014, the State Archives returned 22 records cartons of materials to the Water Resources Archive.


The Irrigation Research Papers was donated in 1975 to the Colorado State University Libraries by Gordon Kruse, a former employee of the USDA Agricultural Research Service. A small addition from Mr. Kruse was donated via Tom Trout, retired director of the USDA Agricultural Research Service's Water Management Research Unit, in June 2017.

Online Materials

Some of the documents and photographic materials in this collection have been digitized and are available through the Colorado State University Libraries website. In the electronic version of this document, some direct links appear in context.

Related Collections

The Water Resources Archive holds the Ralph L. Parshall Collection, the Papers of Louis G. Carpenter, and the Groundwater Data Collection, all of which document Parshall and/or his colleagues. The Agricultural and Natural Resources Archive holds the Records of the Colorado Agricultural Experiment Station.


Processing was completed in October 2015. Materials were rehoused in acid-free folders, envelopes, or polyester sleeves and reboxed. For Series 1, photocopies of numbered and labelled envelopes were made and placed at the front of every folder. Rubber bands, paper clips, and rusty staples were removed and replaced with plastic clips as needed. Newspaper clippings, telegrams, and other acidic papers were inserted between sheets of acid-free paper. Loose photographs and negatives were inserted in archival sleeves or envelopes. Duplicates beyond two or three copies were removed, as were a few items due to deterioration issues. Photographic materials in Series 2 were separated and rehoused by material type. Duplicate images beyond two copies (either prints or print/negative) were removed, as were most images of graphs, charts, and maps. Nitrate negatives were scanned, with some exceptions such as the sets of snow photos, and discarded. Broken unidentified glass plate negatives and highly deteriorated film negatives were also discarded. Each image retains the numbering system found on the original envelopes. A separate item-level inventory for Series 2 can be provided on request. Processing of the 2017 addition was completed in July 2017 and can be found in box 47.

Inventory Note

Note: Title information supplied by the archivist is bracketed. Estimated pagination is preceded by an "e." Two identical copies of the same item are indicated by the phrase "2 copies" at the end of the entry, following the number of pages of each copy.

Guide to the Irrigation Research Papers
Edited Full Draft
Prepared by Patricia J. Rettig, Naomi Gerakios Mucci, and Madeline Johannsen; revised by Patricia J. Rettig
Copyright 2017
Language of description
Script of description
Language of description note
Finding aid written in English.

Repository Details

Part of the CSU Libraries Archives & Special Collections Repository

Fort Collins Colorado 80523-1019 USA