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Infiltration Test Results

A B

E

A. YVWD fire hydrant setup
B. 4" fire hose along east side of 2nd St
C. Post-excavation / fencing
D. Test in progress (Day 1)
C C D E. Test in progress (Day 4)

DRY SOIL (SILT)
10-12 FEET BELOW
CHANNEL BOTTOM

Conclusions:
- Results of infiltration testing confirm/indicate that the site is favorable for recharge.
- Full-scale basin initial infiltration rates (based on 50% of measured field-scale testing infiltration
rates) are estimated at 26.0 feet/day. Long-term infiltration rates (based on 50% of full-scale basin
Test Start Aug-27-2018 initial infiltration rates) are estimated at 13.0 feet/day.
Test End Sep-10-2018 ´ - While long-term estimates consider expected clogging of the basin bottom from SWP water,
actual long-term rates will be dependent on the specific site recharge goal and implementation
Basin Dimensions (L x W) (ft) 45 x 20 0 400 Feet of a basin maintenance plan.
Average Water Height (ft) 2.0 - High infiltration rates are representative of almost exclusively coarse-grained deposits (sand/gravel)
2
Infiltrating Area Basin Bottom (ft ) 960 identified during excavating and in EX-3.
- High rates may also be partly attributable to the proximity of the test basin to a large-diameter
2
Infiltrating Area Basin Bottom + Walls (ft ) 1,270 Chicken Hill Fault conveyance pipe along the east side of 2nd St, presumably set in a gravel-filled trench.
Total Water Added (gallons) 3,426,110
Recommendations:
Total Water Added (acre-feet) 10.5 X Y - Depending on the size of the full-scale basin, pilot-scale infiltration testing is recommended
High (ft/d) 59.18 " ) to confirm full-scale initial infiltration rates and to identify potential site vadose zone storage
Infiltration Rate Boring EX-3
Low (ft/d) 44.8 capacity constraints due to recharge mounding. Installation of a monitoring well adjacent to
(Constant-Head) Wilson Creek III the site is recommended to confirm the arrival and mounding effect of recharge water during
Average (ft/d) 52.0 Test Site pilot testing and to track future groundwater level changes.
Infiltration Rate High (ft/d)
N/A; too fast YVWD
(Falling-Head) Low (ft/d) Figure 9
Hydrant
Full-Scale Basin Est. Initial Infiltration Rate (ft/d) 26.0 YVWD Wilson
Production Well
Full-Scale Basin Est. Long-Term Infiltration Rate (ft/d) 13.0 Creek III

Yucaipa Sustainable Groundwater Management Agency - January 23, 2019 - Page 53 of 137