Page 45 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

Calimesa/Oak Glen Subbasins

City of Yucaipa at California Street: Pilot‐scale infiltration testing is recommended to confirm
initial full‐scale infiltration rates and identify potential site vadose zone storage capacity
constraints due to recharge mounding. Installation of one monitoring well adjacent to the
pilot basin is recommended to confirm arrival of recharge water at the water table (which is
relatively deep at 342 feet‐bgs) and monitor future groundwater level changes.

Wildwood Creek Basins: Pilot‐scale infiltration testing is recommended to identify potential
site vadose zone storage capacity constraints due to associated recharge mounding, which
may be exacerbated by the South Mesa Barrier. Installation of a monitoring well west of the
South Mesa Barrier and monitoring of water levels during pilot testing is recommended to
better understand the subsurface flow dynamics across the South Mesa Barrier.

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10 Street and Avenue E: Water level differences of approximately 300 feet across the
Chicken Hill Fault indicate that the hydraulic connection between this site and the Western
Heights Subbasin is likely to be poor. However, further investigation is needed to confirm
this interpretation. If there is interest in developing a recharge facility at this site, pilot‐scale
infiltration testing is recommended with installation of a monitoring well east and west of
the Chicken Hill Fault.

Gateway/Wilson Creek Subbasins

Oak Glen Creek Basins: If site recharge goals are expected to exceed the operational
capacity of the basins, we recommend the removal of the upper 3 feet of sediment in each
of the basins prior to future active recharge. Pilot‐scale testing is not critical at this site.

Wilson Creek Basins: If site recharge goals are expected to exceed the operational capacity
of the basins, we recommend the removal of the approximately upper 3 feet of sediment in
each of the basins prior to future active recharge. Pilot‐scale testing is not recommended at
this site.

Wilson Creek III: Depending on the size of the full‐scale basin, pilot‐scale infiltration testing
is recommended to confirm full‐scale initial infiltration rates and to identify potential site
vadose zone storage capacity constraints due to recharge mounding. Installation of a
monitoring well adjacent to the site is recommended to confirm the arrival and mounding
effect of recharge water during pilot testing and to track future groundwater level changes.

Infiltration Testing at Eleven
Investigation Sites in the Yucaipa
Basin, Yucaipa Valley, CA 24 TODD GROUNDWATER

Yucaipa Sustainable Groundwater Management Agency - January 23, 2019 - Page 43 of 137