The Big Chino Subbasin is a groundwater basin that includes the Verde River headwaters in Yavapai County in north-central Arizona. Groundwater in the Big Chino Valley discharges to wells (by pumping), by evapotranspiration, and to the upper Verde River springs, which form the headwaters of the Verde River. Groundwater also discharges to short perennial reaches of Williamson Valley Wash, Walnut Creek, and a small number of small, ungaged springs and seeps. To monitor changes in groundwater storage and to identify aquifer-storage properties, a network of repeat microgravity stations and groundwater-level monitoring stations was established in the Big Chino and Williamson Valleys in 2010. In addition, the project maintains a streamgaging station on Williamson Valley Wash (station 09502800).
Summary of study findings (Kennedy and others, 2019):
- Small decreases in groundwater storage were observed throughout the study area from 2010 to 2017.
- The last major groundwater recharge event (when groundwater levels rose regionally in response to prolonged precipitation) was winter 2004-2005.
- During the 2010–2017 period, groundwater levels declined most rapidly in the upland area to the west of Big Chino Wash. The highest rates of decline were near the center of the study area around Walnut Creek, with smaller declines near the northern and southern extents. Groundwater-level declines were also widespread in the Paulden area and to a lesser extent in the Williamson Valley Wash area.
- Based on relatively large water-level changes accompanied by small storage changes, water levels at several locations in the Paulden and Big Chino Water Ranch areas appear to represent semi-confined aquifers.
Monitoring Sites
Sites used in this study are shown in the interactive map at the upper right. Continuous groundwater-level monitoring is ongoing at 5 locations (blue markers), and streamgaging at 4 locations (red markers). Repeat microgravity data is collected at 33 stations (yellow markers).
Additonal Site Information and Data
Groundwater-Level Monitoring Sites
- B-18-02 20DBB [PILOTS REST]
- GIPE WELL (SRP MONITORING WELL)
- B-18-03 26BBC1 [WINEGLASS RANCH]
- B-19-04 10CCB2 [WMW 3]
- B-19-04 05ABA1
- B-20-04 33CBD2 [WMW 2]
Streamgaging Sites
- DEL RIO SPRINGS NEAR CHINO VALLEY, AZ
- BIG CHINO WASH AT PAULDEN, AZ
- VERDE RIVER NEAR PAULDEN, AZ
- WILLIAMSON VALLEY WASH NEAR PAULDEN, AZ
Repeat Microgravity Sites
- Repeat microgravity data collected from 2001-2017 at 33 stations are available in a data release.
- Overview
The Big Chino Subbasin is a groundwater basin that includes the Verde River headwaters in Yavapai County in north-central Arizona. Groundwater in the Big Chino Valley discharges to wells (by pumping), by evapotranspiration, and to the upper Verde River springs, which form the headwaters of the Verde River. Groundwater also discharges to short perennial reaches of Williamson Valley Wash, Walnut Creek, and a small number of small, ungaged springs and seeps. To monitor changes in groundwater storage and to identify aquifer-storage properties, a network of repeat microgravity stations and groundwater-level monitoring stations was established in the Big Chino and Williamson Valleys in 2010. In addition, the project maintains a streamgaging station on Williamson Valley Wash (station 09502800).
Summary of study findings (Kennedy and others, 2019):
- Small decreases in groundwater storage were observed throughout the study area from 2010 to 2017.
- The last major groundwater recharge event (when groundwater levels rose regionally in response to prolonged precipitation) was winter 2004-2005.
- During the 2010–2017 period, groundwater levels declined most rapidly in the upland area to the west of Big Chino Wash. The highest rates of decline were near the center of the study area around Walnut Creek, with smaller declines near the northern and southern extents. Groundwater-level declines were also widespread in the Paulden area and to a lesser extent in the Williamson Valley Wash area.
- Based on relatively large water-level changes accompanied by small storage changes, water levels at several locations in the Paulden and Big Chino Water Ranch areas appear to represent semi-confined aquifers.
Monitoring Sites
Sites used in this study are shown in the interactive map at the upper right. Continuous groundwater-level monitoring is ongoing at 5 locations (blue markers), and streamgaging at 4 locations (red markers). Repeat microgravity data is collected at 33 stations (yellow markers).
Additonal Site Information and Data
Groundwater-Level Monitoring Sites
Sources/Usage: Public Domain.A-10 absolute gravity meter near a monitoring well - B-18-02 20DBB [PILOTS REST]
- GIPE WELL (SRP MONITORING WELL)
- B-18-03 26BBC1 [WINEGLASS RANCH]
- B-19-04 10CCB2 [WMW 3]
- B-19-04 05ABA1
- B-20-04 33CBD2 [WMW 2]
Streamgaging Sites
- DEL RIO SPRINGS NEAR CHINO VALLEY, AZ
- BIG CHINO WASH AT PAULDEN, AZ
- VERDE RIVER NEAR PAULDEN, AZ
- WILLIAMSON VALLEY WASH NEAR PAULDEN, AZ
Repeat Microgravity Sites
- Repeat microgravity data collected from 2001-2017 at 33 stations are available in a data release.
- Data
- Publications
- Partners