Page 28 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

provide water to the test basin. The low‐pressure alarm was never triggered during the field
investigation.

2.4. MONITORING ACTIVITIES

The telemetry built in to the engineered water conveyance and flow control system
minimized the need for onsite monitoring. Nevertheless, documentation of water meter
readings for each test basin and maintenance of the systems was needed, especially at three
sites where flows into the test basin fell below the minimum threshold of the digital paddle
meter (approximately 25 gpm). For these three tests, routine twice‐weekly site visits by DRE
staff were supplemented by additional site visits by Valley District staff to document water
meter readings and calculate average vertical infiltration rates for time periods between
meter readings.

It is likely that recharged water reached the water table at some investigation sites during or
following infiltration testing. Groundwater level monitoring was conducted during testing at
one site (Wildwood Creek Basins), where an existing piezometer (YRP‐PZ3; constructed in
EX‐4) is located relatively close to the test basin, and the depth to water (104 feet‐bgs in
2014) is shallow enough that a measurable groundwater level response was expected.
Confirmation of such a water level response is useful for validating the vertical migration of
recharge water and inferring the degree of horizontal spreading of recharged water below
the test basin. Water level monitoring in existing piezometers at the Wilson Creek Basins
and Oak Glen Creek Basins was not performed, due to the significant horizontal distance
between the piezometer and test basin and relatively deep water table at both sites (272
and 302 feet‐bgs in 2014, respectively).

2.5. BEST MANAGEMENT PRACTICES

All field activities were conducted to ensure minimal disturbance to native vegetation and
minimize soil erosion along channel banks. The following site management practices were
implemented to satisfy requirements specified by the SBCFCD:

 No sediments were discharged to the storm drain system or receiving waters.
 Sediments generated on the construction site were retained.
 No construction‐related materials, waste, spills, or residue were discharged to
streets, drainage facilities, receiving waters, or adjacent property by wind or runoff.
 Non‐stormwater runoff from equipment, vehicle washing, or any other activity were
contained within the project site.
 Erosion from slopes and channels were prevented.
 Grading was not conducted during the wet season (October 1st through May 31st).
All erosion‐susceptible slopes were protected to prevent sediment discharge from
the project site. Straw wattles were used to contain temporary stockpiled soils.

Infiltration Testing at Eleven
Investigation Sites in the Yucaipa
Basin, Yucaipa Valley, CA 8 TODD GROUNDWATER

Yucaipa Sustainable Groundwater Management Agency - January 23, 2019 - Page 27 of 137