DWR_3459163

• Division: 2
• Plan ID: 6082
• Plan Name: SUPER DITCH IWSA
• Document Type - SWSP: Approval
• Document Date: 6/28/2019

Cristyn Radabaugh
June 28, 2019
Page 4 of 10
8) For the Mayhoffer East Farm, the Engineers do not agree that the return flows
historically accrued to the river as tailwater. See Enclosure 3 for an analysis
performed by the Division of Water Resources Hydrogeological Services team (Matt
Sares). By no later than August 1, 2019, Applicants must perform the lagged return
flow analysis using the horizontal permeability found in the fractured Fort Hays
Limestone and provide a proposed unit response function to be applied to the
groundwater returns from this farm. It shall be assumed that 70% of the return flow
from the farm will be lagged using the updated analysis.
9) For the first half of November and the second half of March the return flow obligation
should equal the daily surface water return flow plus half of the monthly lagged
groundwater return flow. For the second half of November and first half of March the
return flow obligation should be half of the monthly lagged groundwater return flow.
An exception to the preceding March and November requirements are that no return
flows are required prior to operation of the project. As such, return flows in the first
month of the plan will be distributed from the plan start date through the remainder
of the month. Return flow obligation that accrues from November 15 through March 14
shall be replaced to the Pueblo Winter Water Program and Conservation Storage in
John Martin Reservoir as determined by the Division Engineer. Return flow obligation
that accrues March 15 through November 14 must be replaced to the locations shown
in Figure 2 during the irrigation season. However, should the amount or timing of the
recharge deliveries prove insufficient to maintain return flows during the winter
storage season, any remaining obligations must be calculated and distributed to either
the Pueblo Winter Water Storage Program or to John Martin Reservoir Conservation
Storage in proportion to the historical return flow location above or below the Fort
Lyon Canal headgate. Replacements must be provided with the timing specified
below. During November 15 to March 14, replacement of lagged deep percolation
return flow obligations may be aggregated as approved by the Division Engineer so long
as there is no injury to the Winter Water Storage Program, Colorado water rights,
Conservation Storage in John Martin Reservoir or the Kansas -Colorado Arkansas River
Compact.
10) Following an option available in the Lease Fallow Tool, and the proposal of the
Applicant, the monthly and annual consumptive use will be limited by the following
maximum values which are the averages of the three greatest months and three
greatest years of each study period. The maximum consumptive use credit for the
three years of operation is based on the maximum ten year period within the study
period divided by ten years and multiplied by three years of operation.
Monthly, Annual and Maximum Three Year Consumptive Use Credits
(All Values in Acre -Feet)
Farm
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Annual
(Avg of
Max 3)
Maximum
Three Year
Total
Thetin
12.8
27.2
48.1
56.2
54.2
50.0
36.3
35.1
19.0
257.9
670.8
Mayhoffer West
5.2
13.1
24.9
32.4
32.2
29.5
20.5
18.4
9.1
143.0
352.2
Mayhoffer South
7.1
7.0
10.1
22.3
19.9
23.8
14.6
10.1
4.9
79.1
191.9
Mayhoffer East
2.0
1 3.7
1 5.1
5.5
5.4
1 5.1
3.7
1 3.3
1.7
1 32.9
78.7