OCR Text |
Show per year. The difference, an average of 1,600 acre- feet per year, plus any diversions from Beaver Creek, is the conveyance loss of the canal. The discharge of Beaver Creek is not measured, but the creek enters the Weber River between the stations near Oakley ( site 2, fig. 5) and near Peoa ( site 4, fig. 5). No other perennial tributaries enter this reach of the river, although the Weber- Provo diversion is taken out: the difference in average discharge at the two stations, adjusted for the canal diversion, should therefore approximate the average discharge of Beaver Creek. Although the average discharge of the Weber River near Oakley for the entire long period of record is 159,300 acre- feet per year, the discharge near Oakley for the period of record available near Peoa is smaller- about 139,000 acre- feet per year. The Weber- Provo Canal diversion ( average for the period 50,600 acre- feet per year) is removed from the river below this station, leaving about 88,500 acre- feet per year as the discharge of the main river above the gaging site near Peoa. The average discharge at the station near Peoa, however, is 107,100 acre- feet per year; the river gains 18,600 acre- feet per year ( average) between the two stations. Some of the gain is undoubtedly ground- water discharge from the unconsolidated deposits in Rhodes Valley, but most of the gain is the discharge of Beaver Creek; an arbitrary estimate of the contribution from Beaver Creek is about 17,000 acre- feet per year. The gaging station on East Canyon Creek is many miles downstream from the area of this study; less than half the drainage area of the creek above the gaging station is in the study area. It is probable, therefore, that the average discharge of East Canyon Creek from the study area does not exceed 15,000 acre- feet per year. Chemical quality All surface water from the Weber River drainage basin that was analyzed was chemically suitable for domestic, stock, and irrigation use. Chemical analyses of seven samples of surface water from the Weber River drainage basin are reported in table 5. All the samples are dilute calcium bicarbonate type water. The most concentrated of the seven samples ( 445 mg/ l) was from Silver Creek at the old Silver King Mine near Park City. The stream at that point almost certainly included ground water discharging from the mine tunnels, which is more concentrated than most surface water in the area. GROUND- WATER HYDROLOGY Ground water in the consolidated rocks The consolidated rocks in the Heber- Kamas- Park City area are an important element in the total ground- water system of the area. Springs and wells that discharge water from the consolidated rocks are the principal source of supply for water users in the mountains. Moreover, much of the water that enters the rocks in the mountains either reappears as springs along the margins of the valleys or moves into the unconsolidated valley fill as recharge in the subsurface. Water- bearing units The consolidated rocks underlying the Heber- Kamas- Park City area range in age from Precambrian to Quaternary. A generalized stratigraphic summary of the consolidated rocks is |