OCR Text |
Show boundary of the Uinta Hydrologic Area is approximately 4,600 feet above sea level. The mean elevation of the area is 6,700 feet. Fifty percent of the total area shows a variation of 1,560 feet in elevation. This means that one- half of the total area lies, for example, between 5,000 and 6,560 feet above sea levelo Minerals Economic minerals in the region are confined mainly to the nonmetal- lics0 Oil and gas are of great economic importance. The first commercial oil field in Utah, the Ashley Valley field, began production in 1948 of 300 barrels per day. In 1962 oil production in Uintah County had risen to an annual output of 5,739,672 barrels and gas to 22,351,935 million cubic feet. Map # 6 shows oil and gas fields and pipelines in the Uinta Hydro- logic Area. Oil Shale and Coal deposits are shown on map # 7. The most abundant single mineral resource in the Uinta Hydrologic Area is oil shale. East central Uintah County contains the highest grade oil shale in the State of Utah. Although there is no production at the present time, the potential is great. On the basis of 15 gallons per ton recovery of shale oil ( much of it runs considerably higher), it is estimated that the Uinta Basin could produce about 100 billion barrels of shale oil once competitive processes have been perfected. Much of the area is also underlain by deeply buried Cretaceous strata which is probably coal bearing. There are four fields where important coal seams appear at the surface: Tabby Mountain, Henry's Fork, Vernal and Book Cliffs fields. There is no coal mined at the present time, but there is potential for future production. Seasonal Distribution of Flow Map # 8 shows the percentage of annual flow that normally occurs in each month. The average monthly flow for a 12- month period would be 8.5 percent per month. Actual monthly flows range from zero to 38 percent. The map represents the average monthly flows for the water years 1960- 1969 for each station, except station 2850 which began operating in the 1964 water year. The water year begins October 1 and ends September 30 ( i. e. the water year 1964 begins October 1, 1963 and ends September 30, 1964). In the Uinta Hydrologic Area peak flows occur in April, May, and June. This is a result of rapidly melting snow and associated heavy runoff. Mean Annual Runoff Stream flow measurements alone are not sufficient for determining the total natural water resources of an area. In addition, many of the smaller streams which are characteristic of water producing areas are not measured. In order to provide a basis for determining runoff from ungaged drainage areas the water yield or runoff map has been developed. The physical characteristics and precipitation falling upon the ungaged watersheds were used to estimate the long- term mean annual water yield or runoffc The surface runoff for any watershed or drainage area can be determined by measuring the area between adjacent water yield lines and multiplying by the average depth of the area. The values on map # 9 represent the mean annual runoff for the period 1931- 1960. |