2013-05-30_HYDROLOGY - M1983090

• Permit No: M1983090
• IBM Index Class Name: HYDROLOGY
• Doc Date: 5/30/2013
• Doc Name: SWSP
• From: OSE
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: ECS
• Media Type: D
• Archive: No

Mr. Andy Rodriguez
Poudre Pits Aggregate Mine SWSP
May 29, 2013
TABLE C - SUMMARY OF DEWATERING IMPACTS
Page 4
Site
2013 Direct
Accretions
(acre -feet)
2013 Lagged
Accretions
(acre -feet)
2013 Lagged
Depletions
(acre -feet)
Net Balance
(acre -feet)
Firestein
-
0.64
-0.86
-0.22
Tigges
-
24.39
-32.53
-8.14
Roberts
-
3.86
-5.14
-1.28
North la Poudre
.05
0.41*
-38.26
-37.80
La Poudre
-
2.42
-3.23
-0.81
Total
.05
31.72
-80.02
-48.25
" Does take into account any dewatering recharge that may have occurred in 2012
Lagged Depletions
The IDS AWAS stream depletion model was used to determine the lagged depletions from
evaporation, operational losses, and post dewatering operations to the Cache La Poudre River. The
aquifer characteristics used in the model are shown in the following Table.
TABLE D - AQUIFER CHARACTERISTICS
The lagged combined evaporative and operational depletions in 2013 will be 235.49 acre -feet.
The lagged combined post dewatering depletions and accretion from the stated recharge creates a net
depletion in the amount of 48.25 acre -feet. Therefore the total depletions owed to the river for this
SWSP approval period is 283.74 acre -feet. See Table 10 column 2a for the monthly distribution of the
total losses.
Replacement
The proposed source of replacement water for this combined plan is historical consumptive use
credits available from 13 shares of the Whitney Ditch comprising 5 shares used at the Tigges farm, and 8
shares used at the Firestein farm. Historically 10 Whitney Ditch share were used on the Tigges farm to
irrigate 120 acres. Firestein farmed 134 acres with 10 Whitney Ditch shares. This plan projects a farm
headgate delivery of 31.17 acre -feet per share for a total of 405.28 acre -feet. The total consumptive use
available for the 13 shares of Whitney Ditch averaged 208.4 acre -feet (See Tables 8, 9 & 10). The
Tigges farm owner, through the mining lease, has allowed the operator to use all necessary Whitney
Ditch water that was currently being used on the property. For this SWSP the operator will be using 8 of
the 10 Tigges Whitney Ditch Shares. Arapahoe County Water & Wastewater Authority ( ACWWA) has
ownership of the Firestein Whitney Ditch Shares. The operator has entered into a lease (attached) with
ACWWA for this SWSP approval period to lease 7 of the Firestein Whitney Ditch Shares. Of the 7
shares, 5 will be used for this SWSP.
X
S
T
Mine Site / Parcel
Distance from centroid
Specific Yield
Transmissivit y
to the river (ft)
(gpd /ft)
Firestein
1,035
0.20
120,000
Tigges
3,600
0.20
120,000
Roberts
3,435
0.20
120,000
La Poudre
1,500
0.20
50,000
North La Poudre
2,500
0.20
50,000
The lagged combined evaporative and operational depletions in 2013 will be 235.49 acre -feet.
The lagged combined post dewatering depletions and accretion from the stated recharge creates a net
depletion in the amount of 48.25 acre -feet. Therefore the total depletions owed to the river for this
SWSP approval period is 283.74 acre -feet. See Table 10 column 2a for the monthly distribution of the
total losses.
Replacement
The proposed source of replacement water for this combined plan is historical consumptive use
credits available from 13 shares of the Whitney Ditch comprising 5 shares used at the Tigges farm, and 8
shares used at the Firestein farm. Historically 10 Whitney Ditch share were used on the Tigges farm to
irrigate 120 acres. Firestein farmed 134 acres with 10 Whitney Ditch shares. This plan projects a farm
headgate delivery of 31.17 acre -feet per share for a total of 405.28 acre -feet. The total consumptive use
available for the 13 shares of Whitney Ditch averaged 208.4 acre -feet (See Tables 8, 9 & 10). The
Tigges farm owner, through the mining lease, has allowed the operator to use all necessary Whitney
Ditch water that was currently being used on the property. For this SWSP the operator will be using 8 of
the 10 Tigges Whitney Ditch Shares. Arapahoe County Water & Wastewater Authority ( ACWWA) has
ownership of the Firestein Whitney Ditch Shares. The operator has entered into a lease (attached) with
ACWWA for this SWSP approval period to lease 7 of the Firestein Whitney Ditch Shares. Of the 7
shares, 5 will be used for this SWSP.