Laserfiche WebLink
presented in Figure C-3, by precipitation. Precipitation <br /> amounts are based on U.S. Weather Bureau records at Boulder, <br /> Colorado. Dry year conditions are based on 1954 evaporation <br /> and precipitation data and wet year on 1969 evaporation and <br /> precipitation measurements. The net depletion values are <br /> contained in Figure C-4 along with the net water loss for <br /> irrigation consumptive use. <br /> Irrigation consumptive use for the Boulder area was evaluated <br /> by two methods. The first is the Blaney-Criddle method <br /> which is better established, simpler, and uses data that <br /> are generally easy to acquire for a given area. Recent <br /> investigations, however, indicate that the Jensen-Haise <br /> • method yields more accurate results than the Blaney-Criddle <br /> method, particularly when applied to areas of higher elevation <br /> and short growing seasons. The Jensen-Haise method is a <br /> more recent development and embodies more parameters that <br /> directly affect evapotranspiration of water by plants. It <br /> is, however, somewhat more difficult to apply and utilizes <br /> data that are not always readily available. Both methods <br /> indicate the amount of water consumed by plant growth if an <br /> adequate supply is available during the growing season, a <br /> condition which has generally existed on the site in the <br /> • past and will occur in the future. The results of consumptive <br /> use calculations for pasture grass in Boulder by the two <br /> methods compared closely, as indicated by Figure C-5. <br /> C-10 <br />