Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992-93
- Geological Survey, Mercury, NV (United States)
Ground-water recharge occurred after five separate streamflow event periods in the Pah Canyon area of Fortymile Wash approximately 10 kilometers from Yucca Mountain, Nevada during 1992-93. Ground-water levels rose in two wells, UE-29 a No.1 and UE-29 a No.2, and one neutron-access borehole, UE-29 UZN-91, after each streamflow event period. A maximum rise of 2.9 meters occurred at UE-29 a No.1 thirteen days after the largest streamflow event where depth to water changed from 27.3 to 24.4 meters. Water levels fluctuated 3.89 meters in UE-29 a No.1, 2.92 meters in UE-29 a No.2, and 2.10 meters in UE-29 UZN-91 during the period January, 1992 to September, 1993. During two of the streamflow event periods, one in 1992 and one in 1993, there was flow around the neutron-access borehole located in the Fortymile Wash channel. Three other streamflow event periods were documented in Pah Canyon Wash but the streamflow infiltrated prior to reaching the neutron-access borehole location. Volumetric-water-content profiles were measured periodically in the neutron-access borehole. After the 1992 streamflow event period, water content increased in the upper six meters of the unsaturated zone. After the 1993 streamflow event period, water content increased in the entire unsaturated section, approximately 16 meters thick at the neutron-access borehole. Water levels in the neutron-access borehole rose even when there was no apparent water movement through the unsaturated zone as inferred by changes in the volumetric-water contents. This rise is attributed to ground-water recharge from nearby infiltration of Pah Canyon Wash streamflow. A groundwater mound probably formed beneath Pah Canyon Wash and spread laterally as evidence by larger rises in water levels in UE-29 a No.1 and UE-29 a No.2, which are closer to Pah Canyon Wash than UE-29 UZN-91.
- Research Organization:
- American Society of Civil Engineers, New York, NY (United States); American Nuclear Society, La Grange Park, IL (United States)
- OSTI ID:
- 60922
- Report Number(s):
- CONF-940553--Vol.4
- Country of Publication:
- United States
- Language:
- English
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Estimated ground-water recharge from streamflow in Fortymile Wash near Yucca Mountain, Nevada
Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993