ABSTRACT
Before the 1960s, the availability of hydrologic data was very limited. Short records of streamflow and precipitation were available, but soils data, maps of land cover and use, and data on temporal watershed changes were generally not available. In addition, the availability of computers was limited. These limitations of data and computational firepower restricted the types of hydrologic methods that could be developed for general use. Flood frequency analysis was a staple of hydrologic modelers. It required limited amounts of data and was appropriate for the computational abilities of the era.
