CRDSS_Task1_15-17_ColoRiver_IrrigationReturnPatterns

• Title: CRDSS Task 1.15-17 Colorado River Basin Representative Irrigation Return Flow Patterns
• Description: The purpose of this task was to develop return flow patterns for both the monthly and daily CRDSS planning models using geologic parameters representative of actual locations of irrigated acreage in each of the five CRDSS basins and a methodology that is acceptable and can be reproduced.
• Decision Support - Doc Type: Task Memorandum
• Date: 1/20/2003
• DSS Category: Surface Water
• DSS: Colorado River
• Basin: Colorado Mainstem
• Contract/PO #: C153933, C154062
• Grant Type: Non-Reimbursable
• Bill Number: SB92-87, HB93-1273, SB94-029, HB95-1155, SB96-153, HB97-008
• Prepared By: Leonard Rice Engineering

Figure 2
Monthly Ground Water and Total Returns as Percent of Recharge
Lands Closer to Live Stream
90
so
~o
60
d
U
d 50
A.
~ 40
a 30
20
10
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Month (Month 1= month of recharge)
f Ground Water Returns ~ Total Returns
Table 3
Monthly Return Flow Pattern -Lands Close to Stream

Month Subsurface Return as a Fraction
of Subsurface Recharge (%) Monthly Return as Fraction of
Total Non-consumed Water (%)
1 57.2 (57.2 x 0.5) + 50 = 78.6
2 22.6 22.6x0.5=11.3
3 6.5 6.5 x 0.5 = 3.2
4 4.3 4.3 x 0.5 = 2.2
5 3.2 3.2 x 0.5 = 1.6
6 2.3 2.3 x 0.5 = 1.2
7 1.7 1.7 x 0.5 = 0.8
8 1.3 1.3 x 0.5 = 0.6
9 0.9 0.9 x 0.5 = 0.5
Total 100.0 100.0
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