Page 49 - Beaumont Basin Watermaster

Beaumont Basin Watermaster
2013 Reevaluation of the Beaumont Basin Safe Yield 3-Apr-15

7.1 Recommended Safe Yield for the Beaumont Basin

Based on the analysis of future basin management scenarios using the groundwater flow model,
the recommended Safe Yield of the Beaumont Basin for the next 10 years is 6,700 acre-ft/yr.

7.2 Other Recommendations

The current groundwater flow model is developed based on the best available data collected to
date. However, there are portions of the Study Area where additional data are necessary to
optimally manage the surface and groundwater resources of the Beaumont Basin. General areas
for additional data collection include (in order of priority):

1. Measurement of surface water flow in selected drainages in the Study Area. At
present there are no stream gages in any drainages in the Study Area. As surface
water and groundwater are linked and as there is currently no data for evaluating this
link, this is the highest priority for collecting additional data. It is recommended to
establish stream gages or other regular monitoring system on the following streams:
i. San Gorgonio Creek
ii. Noble Creek
iii. Marshall Creek
iv. San Timoteo Creek (possibly multiple locations)

2. Additional hydrogeological data in the vicinity of the confluence of Noble Creek and
San Timoteo Creek. This is an area of subsurface groundwater loss from the
Beaumont Basin. However, the area appears to represent a geological transition from
the deeper Beaumont Basin to the shallower and narrower San Timoteo Canyon.
Further, the role of faults as partial barriers to flow is poorly understood in this area.
Multiple Appropriators have expressed interest in either discharging surface water to
or diverting surface water from this area. It will be important to better understand the
impact that these additions/diversions have on the water balance of the Beaumont
Basin before the actions can be quantified from a water rights basis.

3. Additional hydrogeological analysis of the location and orientation of faults in the
southeastern Beaumont Basin area. Multiple faults in varying orientations have been
postulated through this area. However, to date, very few, if any, have been
confirmed. Given that subsurface groundwater flow losses through this portion of the
basin are likely relatively high and the possible mutual interference of pumping by
parties both within and outside the Beaumont Basin, it is important to better
understand the hydrogeology of this area.

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