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The
city of Victor, located in the
Teton River
drainage of southeast Idaho
(Figure 1), receives its drinking water from two sources: springs in the
Game Creek drainage, with supplemental water supplied as needed from the
Willow Creek groundwater well located west of town.
The springs and supplemental well meet current demand, though,
due to rapid growth, Victor will soon require an additional source of
water. The IWRRI project
team would provide the following data and interpretations to the city of
Victor: 1) evaluate the hydrology
of the city springs, 2) delineate recharge areas for these springs, 3)
define potential alternate ground water sources, 4) delineate the
recharge zones for the alternate water supplies, 5) share our results
with the consulting engineers responsible for implementation.
Figure
1.
Map showing the location of Victor, Idaho.
The
most common rock types in Teton
County
consist of limestones and sandstones deposited in an ancient sea.
Later during Cretaceous time the rocks were folded, faulted, and
then exposed at land surface. During
Tertiary time the Yellowstone Volcano erupted depositing an ash-flow
tuff, and extensional faulting produced the north south oriented Teton
Valley. Weathering and erosion
then deposited additional sediment on the older rocks.
Regionally,
the ground water flow system consists of a series of alluvial gravel
aquifers feeding successively larger alluvial gravel aquifer until the
system reaches the alluvial
fan upon which the city of
Victor
resides. Clay-rich sediments
deposited by an ancient lake lie down gradient of the fan forcing most
of the ground water to discharge in springs near the tail of the fan.
Victor
Springs
, located in the lower Game Creek drainage, represent the primary source
of water for the city of
Victor. We think that the springs
tap into a local flow system fed entirely from the unconsolidated
gravels within the Game Creek drainage.
Recharge to
the Victor alluvial fan comes from the fluvial gravel aquifer in the Trail
Creek
Valley
and its tributaries. The
Willow Creek well, which penetrates the Victor fan, is perforated
between 200 and 300 ft below land surface.
Although inexpensive, this style of construction is inefficient.
We
identified three potential targets:
1) a more efficient well on the Victor alluvial fan, 2) Game
Creek fluvial gravels, and 3) Fractured Huckleberry Ridge Tuff aquifer.
We think the Victor alluvial fan is the most promising target
because it stores more water and receives more recharge than the other
targets.
We recommend obtaining additional information
regarding the chemical character of ground water in the Victor area by
analyzing water samples from existing wells completed in the target or
analogous aquifers.
Prior to
drilling a new production well we recommend drilling test wells,
conducting hydraulic tests, and collecting water samples to determine
the suitability of the target aquifer(s).
The following list prioritizes the exploration targets for
additional ground water sources. We
based this list on the relative merit of each from an ease of discovery
versus a risk-of-failure point of view (recognition of the possibility
of failure in any exploration program should be kept close at hand).
The list assumes the chemical quality of all target aquifers is
acceptable. It does not
address requirements that may be imposed by regulatory or administrative
agencies.
1. Redevelop
the Victor City Springs.
2. Drill
a new well on the Victor alluvial fan.
3. Drill
the lower Game Creek gravels.
4. Drill
the fractured volcanic target.
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