2019-01-30_HYDROLOGY - M1977436

• Permit No: M1977436
• IBM Index Class Name: Hydrology
• Doc Date: 1/30/2019
• Doc Name: Substitute Water Supply Plan
• From: DWR
• To: DRMS
• Email Name: JLE
• Email Name: MAC
• Media Type: D
• Archive: No

Aggregate Industries South Platte Combined SWSP January 30, 2019
Plan IDs 3614, 4773, 3624, 4772, 4616, 3437, 3376, 3650, 3668, and 5475 Page 5 of 21

throughout 2019. Note: The Applicant has obtained a decreed plan for
augmentation in water court case no. 1990CW23 to cover evaporation
from up to 66 acres of exposed water surface area in one or more unlined
ponds remaining at the site post mining; however, since final reclamation
of the site has not yet occurred, all depletions from this pit will continue
to be replaced under this SWSP during this plan period.
Exposed Groundwater Surface:​ 49.0 acres
Active Dewatering:​ YES
F-Street Pit
(Lower Poudre River)
Status: ​Mining operations at the F-Street Pit are complete and
reclamation is in progress. Depletions covered by this SWSP are limited
to water lost due to evaporation, as lagged dewatering and operational
depletions are no longer accruing to the river.
Exposed Groundwater Surface:​ 26.2 acres
Active Dewatering:​ No

Depletions
The depletions resulting from evaporation, water lost in mined product, dust control and
concrete batching at each site are shown in Table C below:
Table C – Depletion Summary (all amounts in acre-feet)
Site Name Evaporation Water Lost in
Mined Product
Dust
Control
Concrete
Batching Total Lagged
Depletions
Lagged
Dewatering
Depletions
Impacting
the River​b
Total
Lagged
Depletions
Jeronimus Pit 15.00 0 0 0 15.00 15.81 0 15.81
Hazeltine Pit 0 0 0 0 0 2.37 62.72 65.09
Brighton Pit 13.67 0 0 0 13.67 15.27 2.51 17.77
Tucson South
Pit 5.47 17.17
(583,333 tons) 1.98 0 24.62 16.92 0​c 16.92
Wattenberg Pit 14.65 26.64
(905,000 tons) 1.98 0 43.26 54.51 0 54.51
Platte Valley Pit 159.08 0 12.60 6.73 178.40 186.03 0 186.03
Distel Pit 0​a 0 1.54 0 1.54 1.56 0.04 1.59
Tull Pit 2.58 21.82
(741,214 tons) 0.99 0 25.39 19.04 0​c  19.04
W.W. Farms Pit 136.71 9.31
(316,365 tons) 0.99 1.82 147.01 142.43 0​c 142.43
F-Street Pit 71.79 0 0 0 71.79 71.79 0 71.79
Total -- -- -- -- 520.68 -- -- 590.98
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.
c​ 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.