WSP09016 - Laserfiche WebLink

Home Browse Search

. .' .' t,,?;. i .. . 001912 Purposes Recent developments in the theory of ground water movements7 offer the possibility of evaluating the interchange of surface and ground waters in an irrigated valley bordering a stream. It will be the purpose of this study to apply these methods to the South Platte valley between the Kersey and Julesburg gaging stations to determine whether the surface-water ground-water interchanges in this 140 mile reach can be evaluated with the accuracy needed for practical purposes. Bature of the study The study covers the 20 year period 1939 to 1958 inclusive. Much use is made of the data of a previous study by Mr. J.M. Dille dated at Fort Morgan in May 1961.' He used the records available to him to evaluate the actual consumption of water by crops in Water Districts 1 and 64. His study also contains much data on reservoir operations and reservoir leakage in these two districts. Beginning with the 20 year average flow of the river at Kersey, the flow at Julesburg at the State line, about 140 miles down- stream, is estimated by the following formula: Flow at Julesburg : Flow at Kersey + Precipitation + reservoir leakage return flow + average rate of return flow due to applica- tion of irrigation water - Diversions direct to irrigation - Diversions to storage in reservoirs - Water consumed by growing .cro,ps :I; surface slitn-age in the river bed .:t Seasonal fluctuatioJUJ ~~!~'tu~~~~ ,p.#t'" ~'k-. p,~ .~.. ':-, .:_~. r !he result is to: be compared with the 20 year average of the observed flow ot the river past the Julesburg station. Data on river flows at Kersey and Julesburg were obtained from the published U.S. Geological Survey Water Supply Papers. Data for the 1951-1958 period comes, for example, trom Water Supply Paper Io. 1730' Part 6B.Q Data on precipitation at Fort Morgan was obtained from U. S. Weather Bureau summaries." Reservoir leakage return flows are estimated from data obtained trom the Dille study.' Diversions from the river in the Kersey-Julesburg reach were extracted from BureaU of Reclamation compilations through the courtesy of their Region 7. 10 Estimates of the monthly water requirement of crops was obtained from the American Sooiety of Civil Engineers Paper Ho. 3331 Vol 127 1962 Part III on ftMethod for Estimating Consumptive Use of Water for Agriculture- by Wendell C. Munson F. ASCE.8 Return flows originating in irrigations and precipitation and moving as ground water back to the stream were estimated as the difference between the sum of precipitation and the amounts diverted trom the river and the sum of the estimated reservoir leakage and the estimated con- G sumptive use baeed upon Dille's area of 235 000 ,ao~es under 1~1&.tioD ~, the two D~stricts. ~'"., ~:l!~:~:81F~~t~~y!t:!~~:f:~~~t:~~~~1~~:~~o~~;'inue~ the water prism ot the streamo It represents water held in temporary storage. It passed the upper station but is retained between the upper and lower ,gaging stations. When the flow of the stream diminishes this temporarily stored water contributes to the flow past the lower station. It is estimated on the - ":1 1