2024-06-18_HYDROLOGY - M1977436

• Permit No: M1977436
• IBM Index Class Name: Hydrology
• Doc Date: 6/18/2024
• Doc Name: Substitute Water Supply Plan
• From: Division of Water Resources
• To: DRMS
• Email Name: NCG
• Email Name: JLE
• Media Type: D
• Archive: No

Holcim South Platte Combined SWSP June 18, 2024
Plan IDs 3614, 4773, 3624, 4772, 4616, 3437, 3376, 3650, 3668, 5475, 5829, &t 6243 Page 6 of 26
Depletions
The lagged depletions resulting from evaporation, water lost in mined product (including the
washing of imported material), dust control, slurry wall construction, concrete batching, and
dewatering operations at each site are shown in Table C below:
Table C - Depletion Summary (all amounts in acre-feet)
Dust Lagged
Water Control Dewatering Total
Lost in Concrete Lagged Depletions
Site Name Evaporation g/Slurry Total De Depletions to be
Mined Wall Batchinpletions Impacting
Product Replaced
Const. the River
Jeronimus 12.0 0 0 0 12.0 13.44 0 13.44
Pit
Hazeltine 0 0 0 0 0.0 1.18 33.12b 34.3
Pit
Brighton Pit 2.7 0 0 0 2.7 4.78 2.17b 6.95
Tucson 23.6
South Pit 8.20 (1,600,000 11.9 0 43.7 41.90 0` 41.90
tons
Wattenberg 108.4 0 15.3 0 123.7 120.01 0` 120.01
Pit
Platte 148.5 0 15.3 7.8 195.2 198.58 0 198.58
Valley Pit
25.0
DPG Pit 51.3 (850,000 1.2 0 77.5 76.02 0` 76.02
tons
Distel Pit Oa 0 1.5 0 1.5 1.54 0 1.54
Tull Pit 10.3 0 1.0 0 11.3 22.58 0` 22.58
Irwin- 19.1
Thomas Pit 2.6 (650,000,0 13.4 0 35.1 24.46 0` 24.46
00 tons
W.W. Farms 178.6 0 1.0 6.4 185.9 187.83 0` 187.83
Pit
F-Street Pit 102.0 0 0 0 101.9 93.59 0 93.59
Total 790.5 781.2
a Evaporation is replaced by the City of Longmont under their augmentation plan decreed in water court case no. 09CW271.
b Lagged Dewatering Depletions, as shown in the table, are from past dewatering operations that have ceased but continue
to impact the stream system.
So long as the pit is continuously dewatered, the water returned to the stream system is considered to be adequate to
offset depletions attributable to the dewatering.
A stream depletion model using either the Glover method, or Stream Depletion Factor (SDF)
method (for the Brighton Pit) was used to calculate the lagged depletions to the river. The Glover
method uses four aquifer input parameters for each site as follows: 1) X - distance (ft) from centroid
of exposed groundwater to river, 2) W - distance (ft) from the aquifer boundary through the well
(gravel pit) to the river channel, 3) T - transmissivity of the alluvial aquifer (in gallons per day per
foot) between the well (gravel pit) and the river, and 4) S - specific yield (0.2 was used for all sites).
The parameters used in the model for each site are listed in Table D below.