WSP05690

• File Number: 8407
• Description: Platte River Basin - River Basin General Publications
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 1/1/1978
• Author: Toups Corp
• Title: Water Resources Investigation in the South Platte River Valley - Reach Number 2
• Water Supply Pro - Doc Type: Report/Study

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Losses associated with large channel flows are very great in the

reach of the South Platte River from Masters downstream to

aRproximately Orchard. Depth of flow at high water and at high

flood stage is such that flows which otherwise would remain in the

stream or recharge underlying alluvium actually spill into the

valley fill deposits of the ancient stream channel of the South

ptatte. This ancient channel meanders near the Wiggins and Bijou

No'. 2 Reservoir areas, and occasionally crosses the existing

r1ver at right angles.

Water budget analyses conducted for the South Platte have failed

to account for the tremendous losses incurred in channel losses

during high flow conditions. Magnitudes of unaccountable losses

ar~ substantial. For example, on May 9, 1969, inflow at Kersey

wak 18,000 cfs. Outflow at Balzac, considering travel time, was

111800 cfs. Diversions during this period amounted to only

380 cfs. The balance of river inflow, 5,820 cfs, represents a

10$s to the river. Hydrologic lnventories have failed to

determine the fate of losses; .they definitely do not serve to

retharge reaches of the South Platte downstream to the Nebraska

stAte line. It is conjectured that river outflow serves to

re9harge the ground water basins in the Wiggins area. Flows

typically don't return to the river because they are extracted and

diriJinished in quantity by well irrigation systems.

2-18

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