2019-08-27_HYDROLOGY - M1977436

• Permit No: M1977436
• IBM Index Class Name: Hydrology
• Doc Date: 8/27/2019
• Doc Name: Substitute Water Supply Plan
• From: DWR
• To: DRMS
• Email Name: JLE
• Media Type: D
• Archive: No

Amended Aggregate Industries South Platte Combined SWSP August 27, 2019
Plan I Ds 3614, 47731 3624, 47721 4616, 3437, 3376, 3650, 3668, and 5475 Page 5 of 21
this is an unlined pit. The site will be dewatered continuously
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 Status: Mining operations at the F-Street Pit are complete and
(Lower Poudre River) 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)
Lagged
Water Lost in Dust Concrete Lagged Dewatering Total
Site Name Evaporation Mined Product Control Batching Total Depletions Depletions Lagged
Impacting Depletions
the River'
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 20.81 17.17 1.25 0 39.23 26.68 0 26.68
(583,333 tons)
Wattenberg Pit 14.65 26.64 1.98 0 43.26 54.51 0 54.51
(905,000 tons)
Platte Valley Pit 159.08 0 12.60 6.73 178.40 186.03 0 186.03
Distel Pit Oa 0 1.54 0 1.54 1.56 0.04 1.59
Tull Pit 2.58 21.82 0.99 0 25.39 19.04 Oc 19.04
(741,214 tons)
W.W. Farms Pit 136.71 9.31 0.99 1.82 147.01 142.43 0` 142.43
(316,365 tons)
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.
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 to