Laserfiche WebLink
<br />4 <br /> <br />magnitude of base flow instead of by an analysis of low total flow because <br />total flow will be depleted by some amount. In anticipation of the change in <br />the immediate future of the regimen of flow of Kansas streams, it is essen- <br />tial that information of base-flow probability be available now for water- <br />supply planning. <br /> <br />Base flow is separated from total flow in somewhat different ways <br />by various investigators. As separated for Kansas streams, base flow is <br />considered representative of the firm supply of water. Many water-right <br />holders under the Kansas Water Appropriation Act are entitled to use water <br />directly from a stream. The firm supply of a stream is better represented <br />by base flow which will indicate the probability of meeting a given demand. <br />It is necessary to determine the quantity of this flow component in evalua- <br />ting the water supply for new water-right applicants and in determining the <br />rights of existing water-right holders to water in new developments. <br /> <br />As base flow is largely derived from ground-water sources, know- <br />ledge of the quantity of base flow is an indication of the ground-water poten- <br />tial. Extensive ground-water development can extract a significant por- <br />tion of the base-flow component. Therefore, knowledge of base flow may <br />be helpful in future studies to evaluate how streamflow will be affected by <br />this pumpage and, further, to evaluate the effect that extensive pumpage <br />may have on downstream development works. <br /> <br />Until now, two major obstacles have prevented any comprehensive <br />analyses of base flow. The first obstacle has been the many man-months <br />of skilled effort required to separate each daily component of base flow <br />from total flow at 105 gaging stations in order to compute each monthly <br />mean base flow. A total of about 800,000 station-days of record needed <br />such analysis. A second obstacle has been the difficulty of defining why <br />the distribution of base flow varies throughout the State. The process re- <br />quired an interrelated examination of the dozens of possible factors to find <br />the best combination of factors that are actually significant. The recent <br />availability of digital computers has resolved the second obstacle and given <br />a worthwhile objective for devoting the effort to resolve the first obstacle. <br /> <br />The distribution of base-flow supplies in Kansas is studied in this <br />report, both on an areal and probability basis. On an areal basis, maps <br />illustrate how annual and seasonal base flow varies across Kansas and how <br />base flow compares with total streamflow, ground-water availability, and <br />direct runoff. On a probability basis, comparisons are made with flow- <br />duration curves and low-flow frequency curves of total flow. A major part <br />of the report presents graphs for 84 gaging stations showing selected per- <br />centages of probability of base flow reaching various magnitudes for each <br />month of the year. As the probable magnitude of base flow is likely to be <br />needed at more than 84 places in Kansas, approximate values have been <br />