2018-01-16_HYDROLOGY - M1996060

• Permit No: M1996060
• IBM Index Class Name: Hydrology
• Doc Date: 1/16/2018
• Doc Name Note: Approved SWSP
• Doc Name: Approved SWSP
• From: DNR Water Resources
• To: DRMS
• Email Name: ECS
• Media Type: D
• Archive: No

Poudre Pits Combined SWSP
Plan IDs 3218, 3589 Ft 4585
Table E - Glover Parameters (Dewatering)
January 16, 2018
Page 5 of 10
Site Name
X (ft)
T (gpd/ft)
S
Firestein
1,035
120,000
0.20
Tigges
3,600
120,000
0.20
Roberts
3,435
120,000
0.20
La Poudre
1,500
50,000
0.20
North La Poudre
2,500
50,000
0.20
The lagged combined evaporative and operational depletions in 2018 will be 201.17 acre-
feet. The lagged combined post dewatering depletions, accretions from the stated recharge, and
direct delivery to the river from dewatering operations create a net credit to the river in the
amount of 73.69 acre-feet. Therefore the total net depletions owed to the river for this SWSP
approval period are 127.49 acre-feet. See Table 9 column 3 for the monthly distribution of the
total losses.
Replacements
The proposed sources of replacement water under this SWSP is historical consumptive use
credits available from seven (7) shares of the Whitney Ditch historically used at the Tigges farm,
and water leased from the Central Colorado Water Conservancy District.
Historically 10 Whitney Ditch shares were used to irrigate 120 acres on the Tigges farm. The
Tigges farm owner (Kenny Tigges), through the mining lease, has allowed the operator to use all
necessary Whitney Ditch water that was historically used on the property. For this SWSP period the
operator will be using 7 of the 10 Tigges Whitney Ditch Shares, requiring a dry -up of 84 acres.
The historic consumptive use of the subject Whitney Ditch shares was determined based on
the results of a ditch -wide analysis developed for the Whitney Ditch in case no. 2008CW65 and
utilized in case no. 1990CW23. Based on a study period of 1950 through 1995, the Court found that
the average annual gross river diversion was 10,600.2 acre-feet per year or 33.13 acre-feet per
share. Total average annual farm headgate deliveries were found to be 9,010.2 acre-feet per year,
or 28.16 acre-feet per share, based on a transit loss of 15 under the Whitney Ditch system. The
ditch -wide analysis determined that the overall average consumptive use was 4,400.9 acre-feet per
year or 13.75 acre-feet per share for the 320 total shares, assuming a system loss of 15% and a farm
efficiency of 60%. However, in case no. 2002CW331, 8 shares historically used on 74 acres were
decreed a river headgate diversion of 33.42 acre-feet per share and a consumptive use of 16.32
acre-feet per share (130.5 acre-feet total), based on a parcel -specific analysis. Because of this
larger historic consumptive use amount decreed in 2002CW331, the ditch -wide amount decreed in
2008CW65 was reduced by removing the consumptive use decreed for the 8 shares in case no.
2002CW331 from the total amount and applying the reduced historical consumptive use of 4,270.4
acre-feet to the remaining 312 shares, which resulted in a historical consumptive use of 13.69 acre-
feet per share.
For the 7 Whitney Ditch shares dedicated to this SWSP, total average annual farm headgate
deliveries would equal 136.56 acre-feet. The ditch -wide analysis utilized a return flow split of 50%
surface and 50% subsurface return flows. The return flows during the irrigation season will be
Office of the State Engineer
1313 Sherman Street, Room 821, Denver, CO 80203 P 303.866.3581 y4
I
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