| OCR Text |
Show Average discharge, in cubic feet per second, for the period: 139- 50 1950- 67 1939- 67 1561 156 1561 210 179 192 171 162 164 198 205 200 Station 9- 2185. Blacks Fork near Milburne, Wyo. 9- 2775. Duchesne River near Tabiona, Utah 9- 2790. Rock Creek near Mountain Home, Utah 10- 1285. Weber River near Oakley, Utah 1 Record began in 1940. On none of these streams do the average discharges for the periods 1939- 50 and 1950- 67 differ by as much as 10 percent from the average for the entire period 1939- 67. It appears, then, that the average precipitation over the general area drained by the Provo River was about the same during the two periods, and that the average discharges for the two periods probably are comparable. The comparison shows that the river gains an average of about 11,000 acre- feet per year in Heber Valley. The average annual gain is calculated as follows: Acre- feet Discharge of Provo River at Charleston 139,000 Diversions for irrigation between Hailstone and Charleston + 87,000 Inflow of Drain Tunnel Creek - 12,000 Net 214,000 Discharge of Provo River at Hailstone - 203,000 Average annual gain from ground- water inflow in Heber Valley above Deer Creek Reservoir 11,000 The 11,000 acre- feet of ground- water discharge enters the Provo River in several ways. Much of the valley bottom is marshy, and small springs and seeps are common. Two small tributaries of the river- Rock and Spring Creeks- originate from springs in Heber Valley. Probably much of the ground- water discharge enters the river directly as diffuse seepage. One additional identifiable source of ground- water discharge to the Provo River is infiltration to the Heber City municipal sewage system. During the spring and summer months, when the water table is high, the discharge of the sewage system increases from a winter average of about 300,000 to about 6,500,000 gallons per day ( Howard Hurst, Utah State Dept. of Public Health, oral commun., 1968); effluent from the sewage- treatment plant is discharged to Spring Creek. 12 |
