Page 10 - Beaumont Basin Watermaster

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

3. Developing estimates of surface water runoff and net infiltration from precipitation using
a USGS surface water model of the area.
4. Calibrating the groundwater flow model through December 2012.
5. Reevaluating the safe yield of the Beaumont Basin Adjudicated Area using the calibrated
groundwater flow model.
6. Preparing this report summarizing the findings.

1.3 Safe Yield Reevaluation Approach

The Safe Yield of the Beaumont Basin is a function of the overall water balance of the area.
Changes in water/groundwater inflow to the basin and water/groundwater outflow from the basin
impact the Safe Yield. As groundwater management and land use changes impact the water
balance, they also impact the Safe Yield. A generalized expression of the water balance is as
follows:

Inflow – Outflow = +/- Change in Storage (1)

The water balance equation for pre-developed conditions (prior to human occupation) can be
further expressed as:

(I ss + I mfr + I pr + I str) – (O ss + O et) = S (2)

Where:

I ss = Inflow from Subsurface Underflow

I mfr = Inflow from Mountain Front Recharge
I pr = Inflow from Areal Recharge from Precipitation

I str = Inflow from Infiltration from Runoff in Stream Beds
O ss = Subsurface Outflow
O et = Evapotranspiration

S = Change in Groundwater Storage

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