WSP06416

• File Number: 8027
• Description: Section D General Correspondence - Federal Agencies - USDA - Agricultural Research-Service
• State: CO
• Basin: Statewide
• Date: 8/1/1975
• Author: USDA
• Title: Field Observations of Transient Ground Water Mounds Produced by Artificial Recharge into an Unconfined Aquifer
• Water Supply Pro - Doc Type: Report/Study

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height (H = 5.27 feet) during the initial period of fall.
At pond No.2, the observed mound fell at a rate considerably slower than
that predicted. When we solve equation 6 for a, using the observed data for
the initial 15 days of fall, the mound appears to be reacting as if it had a
radius of 1,440 feet rather than 910 f~et. In part, the reason fOJ: this differ-
ence is the relatively large amount of storage present in the vadose zone be-

Table 2.--storage distribution in the mound and vadose zone
beneath the ponds

Pond No. 1 Pond No. 2

Acre-ft Acre-ft
V ' = total volume metered on the 2-acre pond 32.90 11. 90
a
V.' = volume in vadose zone at beginning of
~
spreading 9.14 10.94
V ' volume of vadose zone at end of spread-
r
ing 17.74 17.44
Vf' = volume in vadose zone at end of observed
fall 15.00 14.44
V' = effective mound volume 27.04 8.40

8
OBSERVED . .
6 0 THEORY
0
.
0
4 NO.2
2
00
I- 0
ILl
ILl 0
"-
.J::. 6

20 30 40
TIME - DAYS

Figure 9.--0bserved and theoretical falling hydro graphs at the center of the two
ponds.

00

10

50

60

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