FLOOD09229 - Laserfiche WebLink

Home Browse Search

eastern slope near the central portion of a large include low precipitation, low humidity, abundant daily temperature range, and generally low winds. mountains act as a barrier preventing the northern eastern storms from penetrating the Upper Arkansas continent. They sunshine, a wide The surrounding cold air or River Valley. The records at the Salida weather station, elevation 7,060 feet, show an average annual precipitation of 10.87 inches. Precipitation varies at Salida from less than 8 inches 1 year in 6 to over 15 inches 1 year in 6. The highest recorded annual precipitation was 17.92 inches in 1961. This was followed by the lowest annual pre- cipitation on record, 4.91 inches in 1962. The monthly distribution of precipitation varies considerably each year. Dry months (less than 0.25 inch of precipitation) are rare for April, July and August. Wet months (more than 2 inches precipitation) occur approximately 1 year in 4 in July, 1 year in 5 in April and in August. Summer thunderstorms account for almost 59 percent of the annual precipi- tation, and account for local high flows. Hail falls occasionally in the study area. Summers are cool in the study area with temperatures reaching into the 900F range a few times each summer. A maximum temperature of 100' F was recorded in August 1902. Temperatures for the summer nights usually drop below 500 F. Winter temperatures, particularly in the daytime, are usually warmer than thoFe found at similar or lower elevations. Periods of extreme cold are of short duration. The lowest temperature recorded at Salida was 300 F below zero in January 1919. The average annual temperature is 46.50 F, and the averge summer temperature is 62.60 F. The average frost-free period is approximately 107 days. Because of the climatic conditions, the irrigated land in the vicinity of the study area is in meadows, native hay, and alfalfa. The area is better adapted to livestock production than cultivation. Dryland farming is almost nonexistent in the upper reaches of the Arkansas River basin. Developments on the flood plains have historically been for range and wildlife, with limited improvements supporting ranching activi- ties. (Reference 1) 2.3 Principal Flood Problems Floodflows in the upper Arkansas River basin occur primarily during the May - July period. These high flows are caused basically by snowmelt and are augmented occasionally by rain. Cloudburst storms over the South Arkansas River and poncha Creek drainage basins are known to have occurred causing peak flows in the study reaches. Unfortunately, detailed information on such flood events were not recorded. 5