C150042 Report

• Contract/PO #: C150042
• Contractor Name: Rio Grande Restoration Project Enterprise
• Contract Type: Grant
• Loan Projects - Doc Type: Report

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3.1.3. Recharge Site Northwest of Monte Vista National Wildlife Refuge
On the Monte Vista National Wildlife Refuge, water levels of six existing wells were measured.
As previously described, two of the wells appear to tap the unconfined aquifer while the
remaining wells tap the confined aquifer.
For each of the wells, ground water level hydrographs have been prepared with time periods
when Monte Vista Canal water was available for recharge superimposed to allow the reader to
observe ground water reaction to recharge. These hydrographs are included as Figures 3-9, 3-10,
3-11, 3-12, 3-13 and 3-14.
3.2 CHANGES IN GROUND WATER LEVEL DUE TO RECHARGE
' 3.2.1 General
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At the recharge sites northeast of Del Norte and at the Brownell site the monitoring well
measurements clearly indicate that ground water levels rise within a few days after the
introduction of surface water into the site. At both sites the neazby canal laterals leak into the
ground water system, complicating the exact quantification of the effect of the recharge pit(s) on
the ground water system.
Using the approach documented in the development of the CSU Well&Pit computer program
described below, the quantity of ground water recharge is a function of site conditions, area of pit
or ditch bottom inundated by water and length of time of inundation. Included on the well
hydrographs in Section 3.1.1 and 3.1.2 the time of inundation of the pit(s) and nearby ditches are
shown so visual correlation between changes in ground water levels and available recharge water
can be made.
In both cases, an increase in ground water levels in monitoring wells following diversion of
water into nearby recharge pit(s) is obvious. However, the rate of recharge during the period
3-11
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