Steady state infiltration processes along the Santa Cruz and Rillito Rivers

Abstract

The principle aim of this study was to outline a new method for determining steady state infiltration rates for the Santa Cruz and Rillito Rivers. A secondary study aim was to apply four alternative infiltration prediction models to study conditions and compare results. The procedure entailed constructing a plan-view map of channel flow conditions from an aerial video, and digitizing the wetted area. Steady state infiltration conditions were demonstrated to have been established on both streams during the study period. Combining the wetted area values with known or estimated inflow/outflow rates, steady state infiltration rates were computed: 1.35 ft/day, or 18.19 acft/ day/mi, for the Santa Cruz River, and 1.65 ft/day, or 40.91 acft/ day/mi, on the Rillito River. Results from the application of the four alternative methodologies showed that Lane's (1983) predicted rates agreed most closely with values determined in this study. The Flug et al. (1980) values differed most dramaticly.