From 1922 to 1988, IIHR carried out one of the very first comprehensive studies of the hydrology of a small river basin. Ralston Creek drains approximately three square miles of present-day eastern Iowa City, land that was farmed when studies commenced. Studies included measurements of rainfall, groundwater, streamflow, and environmental variables. The nearby Rapid Creek watershed was added to the study in 1938.

These studies were oriented toward understanding integration of the complex pathways of the hydrologic cycle. Today the data set is heralded as the longest highly detailed record of a small U.S. watershed in existence.

This record group consists of six archival boxes, mostly filled with data summaries and reports. The data have been used in numerous projects. Some (but not all) reports and papers that are based on these data are included in the record group.

Box 1. 1924–62

• Early Articles on Project. Folder Includes:
  • “Lilliputian Hydraulics” (Paxson, Transit, 1932)
  • “Water Yield from Small Watersheds in Iowa” (Nagler, Journal of AWWA, 1927)
  • “Hydrologic Records in Iowa” (Nagler, Transit, 1924)
• “A Summary of Hydrologic Data, Ralston Creek Watershed 1924–35” (F.T. Mavis and E. Soucek, University of Iowa Studies in Engineering, Bulletin 9, 1936)
• “Ralston Creek Project Progress Report with Rainfall, Runoff, and Ground-water Data.” Seven folders:
  • 1934 (two folders)
  • 1935 (two folders)
  • 1950
  • 1961 (A. Shanmugam)
  • 1962 (K.K. Rao)

Box 2. 1963–68

• “Ralston Creek Project Progress Report with Rainfall, Runoff, and Ground-water Data.” Four folders:
  • 1963 (A.R. Giaquinta)
  • 1964 (D. Squarer)
  • 1965 (M.R. Balakrishana)
  • 1966 (Pawan Kumar)
• “Ralston Creek Project (North and South Branches) with Rainfall, Runoff, and Ground-water Data.” Two folders:
  • 1967 (Kanwar Satija)
  • 1968 (V. Danushkodi)

Box 3. 1969–72

• “Ralston Creek Project (North and South Branches) with Rainfall, Runoff, and Ground-water Data.” Five folders:
  • 1969 (V. Danushkodi)
  • 1970 (K. Gopalakrishnan, two copies)
  • 1971 (V. Danushkodi)
  • 1972 (V. Danushkodi)

Box 4. 1977–79

• “Ralston Creek Project Hydrologic Investigations …
  • For 1977” (Alexander N. Zaphirakos)
  • For 1978” (Alexander N. Zaphirakos)
  • For 1979” (Saleh Ahmed Wasimi, two copies)

Box 5. 1980–83

• “Ralston Creek Project Hydrologic Investigations …
  • For 1980” (Saleh Ahmed Wasimi, two copies)
  • For 1982” (Liang-Hsiung Huang, two copies)
  • For 1983” (Liang-Hsiung Huang, two copies)

Box 6. Miscellaneous (1924–83)

• Field Book, Ground Water Data (Office Copy, 1965–73)
• Field Book, Rain Gage Data (1957–87)
• Daily, Monthly, and Annual Runoff (1924–57)
• Daily Rainfall (1924–55)
• Annual Summary of Daily Rainfall for Gage (1982–83)
• Record of Daily Precipitation (1982–85)