AbstractsBiology & Animal Science

The purpose of this study was to determine the probable annual yield from stream pumping stations and to evaluate the effect of pumped storage reservoirs on downstream flows. The study results were obtained by simulating pumping rates, reservoir capacities and release rates and using mean daily streamflow records. The yield from each of four simulated pumping rates was analyzed for three stream gages with 33, 34 and 37 years of record each. The yields were expressed in terms of their annual probability of occurrence. The simulation of the pumped storage reservoir system was run for a 26 year period of record at one gage with six pumping rates, four reservoir capacities and four release rates. The regulation was described by flow-duration curves and average annual and monthly flow data. A method was outlined to illustrate how an optimum system could be selected. Channel capacities were estimated from field surveys in four northwest Ohio watersheds. These capacities were analyzed to provide a basis for evaluating the practicability of pumped storage streamflow regulation. The results show that during years of relatively low flow there was little to no increase in pumping plant yields when the pumping rate was increased from 10 to 50 csm (cubic feet per second per square mile). The pumped storage streamflow regulation system with a 10.0 csm pumping rate, a 1.0 csm release rate and a 500 acre feet per square mile reservoir (the largest system simulated) reduced the duration of the 1.3 csm flow from 12.0 (natural flow duration) to 0.6 per cent of the time per year, on the average. The natural flow with a 0.6 per cent of the time duration is about 10.0 csm. When the release rate was less than 1.0 csm, with the pumping rate and reservoir volume unchanged, the duration of regulated flows above 1.0 csm increased. For example, the duration of the 1.3 csm regulated flow was 3.4, 6.8 and 10.0 per cent of the time for release rates of 0.5, 0.3 and 0.1 csm, respectively. The system with a 0.5 csm release rate kept the regulated flow between 0.5 and 1.3 csm 87.3 per cent of the time per year, on the average, compared to 11.3 per cent for natural flow. This means that the 0.5 csm regulated flow was equalled or exceeded 90.7 per cent of the time (87.3 + 3.4). This study showed that pumped storage streamflow regulation can provide an alternative to channel modification for solving drainage problems along northwest Ohio streams. The simulation procedure was suggested for investigating pumped storage streamflow regulation, as an alternative to channel modification in future watershed projects. A pilot project (field installation) was recommended for demonstration and further study of pumped storage streamflow regulation.