Laserfiche WebLink
Clearly, the historic conditions on the Colorado River system no <br />longer exist. Peak flows have been drastically reduced which has impacted <br />the sediment transport of the river system. Materials entering the <br />Green and Colorado vfa tributaries during runoff have not been flushed <br />through the system as efficiently by the lower peaks. These materials <br />are still entering the rivers but are now accumulating in sand bars and <br />filling in the maims river channel. A shallower, wider, warmer river has <br />resulted which fluctuates less seasonally but substantially more on a <br />daily basis. All of these physical/chemical changes seem to have benefited <br />the introduced exotic fishes while having detrimental effects on the <br />endemic endangered species. <br />Also, some sections of the Upper Colorado River are now impacted by <br />daily flow fluctuations as a result of power generations at BR dams. <br />The upper Green River and the Gunnison River are areas where daily flow <br />fluctuations occur. These daily fluctuation are much more evident under <br />reduced flow conditions, therefore, the daily fluctuation during spawning <br />and during the postrunoff YOY rearing period are probably having an <br />impact on both Colorado~squawfish and humpback chub survival. The area <br />of impact of daily flow fluctuation is dependant upon the degree of flow <br />change and the base flow Level. However, in the Upper Green River, we <br />believe this area of impact extends from Flaming Gorge Dam downstream <br />beyond Ouray and possibly as far as Sand Wash. <br /> <br />