2012-02-03_HYDROLOGY - M1996052

• Permit No: M1996052
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/3/2012
• Doc Name: SWSP
• From: OSE
• To: Parsons Water Consulting, LLC
• Permit Index Doc Type: Hydrology Report
• Email Name: ECS
• Media Type: D
• Archive: No

Site Name
T
X
W
S
Lohmann Pit
50,000
2,000
4,173
0.2
Rinn Valley Pit
125,000
715
4,173
0.2
Firestone Pit
72,300
2,210
2,262
0.2
Fort Lupton Pit
90,000
1,200
7,996
0.2
Lupton Meadows Pit
90,000
300
4,500
0.2
Mr. Rick Parsons, P.E.
L.G. Everist Combined SWSP
Page 4 of 9
February 3, 2012
Meadows Pit will come from an existing alluvial well, permit no. 57957 -F (WDID 0205018 DI TIRRO
WELL 2), located outside of the approved slurry wall on the Fort Lupton Pit site. Well permit no. 57957 -F
is permitted to provide water for concrete batching and dust suppression. The depletions resulting from
pumping the well, for those uses, will be replaced under this plan.
Continuous dewatering operations at Lohmann, Rinn Valley, and Lupton Meadows Pits are
occurring in order to facilitate dry mining conditions. This water is used for dust control at the Lohmann
and Rinn Valley pit, and is used for concrete production at the Rinn Valley pit. All other water pumped
for dewatering is returned immediately to the river system. The applicant has performed a lagged water
balance for these operations and account for the lagged depletions which is offset by monthly net
accretions. If not already installed, totalizing flow meters must be installed and monthly meter readings
showing dewatering volumes must be reported on the submitted accounting. Future SWSPs will not be
approved unless such meters have been installed. After March 31, 2012, the operator cannot
claim credit for dewatering accretions that exceed lagged dewatering depletions unless such
meters are installed.
A stream depletion model using the Glover method was used to calculate the lagged depletions
to the River. The alluvial aquifer model uses four aquifer input parameters for each site as follows: 1) X-
distance from centroid of the well to the river, 2) W- distance from the aquifer boundary through the well
to the river channel, 3) T- transmissivity of the alluvial aquifer (in gallons per foot/day) between the well
and the river, and 4) S- specific yield. The following parameters for each site listed in the table below
were used in the model:
TABLE E — AQUIFER CHARACTERISTICS
Replacements
Saint Vrain Creek
L. G. Everist owns 7.4 shares of the Rural Ditch Company. Of the 7.4 shares of the Rural Ditch
water, 1 share will be dedicated for this plan for 2012 and 2013. The 7.4 shares of the Rural Ditch were
historically used to irrigate 215 acres of pasture grass, corn and alfalfa. The land historically irrigated by
the 7.4 shares is the same land that is currently being mined at the Rinn Valley Pit. Assuming a 10%
ditch loss and a 55% irrigation efficiency, the dry -year consumptive use of the 7.4 shares was
determined to be 337 acre -feet. The prorated consumptive use for the 1 share is 45.5 acre -feet. The
historical return flow obligation of the 1 Rural Ditch shares will be maintained by the plan. The Rural Ditch
share is delivered to Saint Vrain Creek through an augmentation station near the end of the ditch. The
delivery location is below the Last Chance Ditch headgate and above downstream calling water rights
located on the South Platte River.
L.G. Everist has fully reusable supplies stored in the Rinn Valley Phase 3 Reservoir. A total of
326 acre -feet of water was stored pursuant to a pending September 30, 1987 storage right (Case No.
05CW315) in June and July 2011. According to 05CW315, the water in storage is available for industrial
and replacement purposes among other uses. This water will be pumped to Idaho Creek and delivered
to Saint Vrain Creek during the winter months. The applicant shall obtain prior permission from the