2014-10-30_HYDROLOGY - M1974069

• Permit No: M1974069
• IBM Index Class Name: HYDROLOGY
• Doc Date: 10/30/2014
• Doc Name: Combined SWSP
• From: DWR
• To: Bishop-Brogden Associates, Inc.
• Permit Index Doc Type: Hydrology Report
• Email Name: ECS
• Media Type: D
• Archive: No

Loveland Ready -Mix, Inc. Combined SWSP Page 3 of 6
October 29, 2014
The Applicant has estimated that 2,400 tons of aggregate will be produced from the Larimer
Pit during this plan period. The material is mined below the water table and is washed; therefore
the water retained in the mined product is considered to be 4.0% of the mined material by weight
(9.6 gallons per ton). The Applicant has estimated that 59,300 cubic yards of concrete will be
produced at the Larimer Pit during this plan period. Water consumption for concrete production was
estimated at 1,950,000 gallons based on a consumption rate of 30 gallons of water per cubic yard of
concrete. The Applicant has estimated that 1,700,000 gallons of water will be used for dust control
at the Larimer Pit site during this plan period. Dust control was considered to be 100% consumptive.
Operational depletions at the Larimer Pit will therefore total 3,502,040 gallons, or 10.75 acre -feet,
for this plan period.
The monthly ground water depletions from each pit were lagged to the Big Thompson River
using the Alluvial Water Accounting System (AWAS), which uses the Glover method. The following
parameters were used in the model: the distance (X) from the centroid of the exposed ground water
surface to the river, the width (W) of the aquifer on the side of the river where the pit is located,
the harmonic transmissivity (T); and the storage coefficient (S). The parameters used for each pit
site are shown in the table below.
Table C - Glover Parameters
Site Name
X (ft)
W (ft)
T (gal /day /ft)
S
Larimer Pit
(Pit Nos. 13, 14, 15, £t 18)
200
1,550
50,000
0.2
Mariana Butte Pit
500
1,550
50,000
0.2
Baer Pit
1,500
1,550
50,000
0.2
Lagged depletions resulting from past and projected use of ground water at the pits are
estimated total 136.70 acre -feet during this plan period, as shown in the attached Table 6.
Replacements
The sources of replacement water for this combined plan will be from 120 Barnes Ditch inches
diverted from the Big Thompson River and previously used for irrigation of the mined property and
59.05 out of 200 acre -feet per year of fully consumable water leased from the City of Loveland.
The Barnes Ditch inches were quantified and changed for multiple uses in case no.
2000CW143, including augmentation of depletions resulting from operations at the subject pits. The
120 Barnes Ditch inches were historically used to irrigate varying amounts of land up to 243 acres, all
of which have since been removed from irrigation. Consistent with the decree in case no.
2000CW143, the irrigation season credits for the entire 120 Barnes Ditch inches are 243.5 acre -feet
with a winter return flow requirement of 6.70 acre -feet. Deliveries are limited to the period of May 8
through October 12 of each year. Due to damage to LRM's storage ponds and the river return
augmentation station, LRM is proposing to temporarily take these credits at a different location,
subject to approval of the water commissioner. Credits used to replace depletions for this SWSP will
be bypassed at the Barnes Ditch headgate and left in the Big Thompson River or diverted through the
Barnes Ditch and returned to the Big Thompson River at a temporary bypass location at the water