Page 27 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

Additionally, a robust, automated engineered water conveyance and flow control system
with remote terminal unit (telemetry system) was fabricated by DRE and installed at each
test basin. The flow control system provided the following benefits:

1. The flow rate was typically automatically controlled, providing a high range of
discharge rates to match variable infiltration rates during testing and from site‐to‐
site. Due to very high infiltration capacities at two sites, the largest 3” manual valve
was opened partially to ensure constant water levels were maintained.

2. The flow rate range was controlled by adjustment of the pressure regulator setting
and hand valves to accommodate variable pressure from different water sources.

3. No water storage tank was needed.
4. The system was installed with built‐in telemetry to provide real‐time flow rates into
the basin, ponded water level, and notifications of exceedances of low‐water and
high‐water level thresholds.

5. The system precluded Valley District or DRE staff to manually monitor flow volume
and pond height.
6. Redundancy of flow meters at the hydrant connection and on two 1‐inch and one 3‐
inch discharge lines allowed for flow rates entering the test basin to be reliably
tracked.

7. The flow control system was supported by the edge of the test basin with two
supporting feet at the bottom of the basin. The small footprint did not influence the
infiltrating area of the test basin.

The conveyance system includes a totalizing flow meter, backflow prevention device, and
hand valves (supplied by the owner of each hydrant). Water was conveyed from the hydrant
by a combination of 4‐inch diameter fire hose to an engineered manifold made with rigid
steel pipe. A 4‐inch diameter flexible fire hose was needed to maintain water pressure over
the distances (generally between several hundred feet up to 1,500 feet) and head
differences between the hydrant and test basin. A digital paddle meter was installed on the
4” diameter line before a manifold that separated the flow into three individual discharge
pipes (one 3‐inch diameter pipe and two 1‐inch diameter pipes). A hand valve on the 3”
diameter discharge line, and float valves and totalizing flowmeters on each 1” diameter line
allowed for flow into the test basin to be automatically controlled to maintain ponded water
depths typically between 2.5 and 3.0 feet. The three individual flowmeters were used to
verify flows from the single fire hydrant flowmeter.

The system would also be equipped with high and low water level sensors and telemetry to
communicate if water levels fell below 1 feet or exceeded 4 feet. Additionally, a low‐
pressure sensor upstream of the pressure regulator on the 4‐inch manifold provided an
automated warning if pressure from the fire hose dropped below a certain threshold,
indicating that the water source itself or the fire hose was compromised and not able to

Infiltration Testing at Eleven
Investigation Sites in the Yucaipa
Basin, Yucaipa Valley, CA 7 TODD GROUNDWATER

Yucaipa Sustainable Groundwater Management Agency - January 23, 2019 - Page 26 of 137