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Ground Water-Surface Water Relations in the Silver Creek Area. by
J.A. Moreland 1977
Water
enters the fluvioglacial valley fill in the Silver Creek area from
seepage from the Big Wood River, irrigation return, leakage from canals,
and precipitation. The recharge joins underflow from the Big Wood River
canyon and moves generally southward through the valley. The various
inflow sources cause significant seasonal fluctuations in ground-water
levels. The lithology of the valley fill partly controls the movement of
ground water through the system. . . . . Streamflow measurements made
throughout the area of ground-water discharge show that most of the flow
in Silver Creek is derived from springs issuing from the shallow,
unconfined aquifer near the upstream edge of the confining beds. Over
half the ground-water discharge which feeds the Big Wood River also
rises from the shallow aquifer. However, a substantial part of the
ground-water component of flow in the Big Wood River apparently is
discharged from the downstream part of the confined aquifer near Stanton
Crossing. Seasonal fluctuations in the ground-water component of flow in
Silver Creek are directly related to water-level fluctuations in the
aquifer near the springs. The complex interaction of ground and surface
water is clearly demonstrated in seasonal variations of gains and losses
along Silver Creek. In some downstream reaches near Picabo, the creek
gains flow during periods of high ground-water levels and loses flow
during the period of lower ground-water levels. |