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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TABLE 2-1. GEOLOGIC FORMATIONS AND THEIR BEARING PROPERTIES [a]

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AQqIFER
SYSTEM

GEOLOGIC
FORMATION

WATER BEARING PROPERTIES

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Dune Sand

Usually above ground water surface,
serves as recharge medium, yields
small amounts of water locally.

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Valley Fill
AUuvium

Alluvium

Yields large quantities of water,
receives large amount of recharge.

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Ogallala
Brule
Chadron

Yields small to moderate amounts
of water.

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Lolier
Aq~ifers

Laramie

Fox Hills

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Sandstone
pierre Shale

[al Bjorklund and Brown, 1957.

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Th~ interaction between surface and ground water regimes is

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extiremely dynamic. Recharge to the valley fill aquifers is

generally accomplished by infiltrating surface water flows.

Ground water levels drawn down by heavy pumping are restored

by ~ercolation of surface waters through the permeable alluvium.

Flqws also typically take place from alluvial deposits into the

strieam channel. Accretions into the rJ.ver attributable

to ,tributary seepage exhibit variations in flow which are

related to rivel' stage and seasonal hydrology.

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A balance of inflows and withdrawals from an aquifer must exist

in urder for the volume of water stored in the soil complex to

rem~in constant. Should removal of ground water exceed the amount

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