WSP09016

• File Number: 8407
• Description: Platte River Basin - General Publications
• State: CO
• Basin: South Platte
• Date: 9/9/1968
• Author: Robert E Glover
• Title: Surface Water - Ground Water Interchange in the South Platte Valley Between Kersey and Julesburg Gaging Stations
• Water Supply Pro - Doc Type: Report/Study

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On1915

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(4) Average flow o~ the South Platte at Juleeburg:

Dille:'(19~9-l958 inol)
,
Dille: (Long time records- Presumab17 the
58 years mentioned elsewhere in
the report)

Crawford and Gilderslewte:5
(1930 - 1955 incl - 26 years)

USBR data1o(!ota1s mad.by thia -.r.J.'te3r for
1939-1958 inel - 20 years).
.

318 700 AF/yr

~4O 000 AF/yr
269 300 AF/yr
324 680 AF/yr

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Details otcomputations

The river flows at Kersey and Julesburg were compiled from
published U.S. Geological Survey records. ~

The reservoir seepage loss was taken from the Dille study:

Diversions to irrigation and storage were co',"piled for the
1939-1958 periOd from U. S. Bureau of Reclamationreeords. 10

ConsU$ptive use was estimated from Munson's.data for 235 000
acree."

The average return flow from irrigation and precipitation was
obtained by adding to the 765 440 AF/tr of diversions the
262 000 estimated aore feet of precipitation falling on
235 000 aores in a year and subtracting the 470 000 A~/yr estimated
for the consumptive use on 235 000 acres together with the
200 200 AF/yr of reservoir seepage loss. The average return flow
is then 357 240 AF/yr.

Temporary storage in the river due to changes of depth
associated with flow changes was estimated in the manner described
previously.

Precipitation falling on the irrigated area was considered on
the same basis as irrigation water since on these arBas the
moisture content of the s011 is maintained and rainfall can
penetrate to the water table with about the same facility as
irrif:,;ion water. On the non irrigated areas precipitation pene-
trat. the surface of the ground is assumed to be held near the
surface until it is consumed by plante or evaporation. No contri-
bution to the ground water from precipitation falling on the non
irrigated areas was therefore considered. 4

The amplitude of the seasonal fluctuations of the return flow
originating in the applioation of irrigat~ water was estimated
by the methods desoribed in reference (7) . Charts needed for
aaking this computation ar& reproduced here as figures B and ~ .
An average valley width L of 4.,JIIiles or 21 120 feet was selec~ed
trom a study ot the data in th. USGS Water Supply Paper 1378. An
aquifer eonstant of OC.. , 1.50 ft2/sec was also seleoted from the
pump test data given in this volume. With a period T of one year
or 31 536 000 seconds the chart parameter beoomes

14fT .. 1(4)1.hR(i,~536000)_ .. " =,0.651

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