REP28949

• Permit No: M1993041
• IBM Index Class Name: Report
• Doc Name: ATTACHMENT 1
• Media Type: D
• Archive: No

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Mr. Bill McIntyre
October 13, 1993
Page 2
Reclamation will occur in conjunction with the mining. It is estimated
that up to 26 acres in any given year will be reclaimed to native dryland
grasses, shrubs and trees. The woody plants will be irrigated for up to three
years in order for them to become established. The water will be applied via
a water wagon, sprinkler irrigation system, drip irrigation system, or
combination of these irrigation methods. The annual reclamation irrigation
requirements are estimated to be 50 acre-feet.
Southwestern is the owner of numerous water rights as outlined in
Attachment 1. Table 1 summarizes only those senior water rights owned by
Southwestern, namely those that were included in the first adjudication (June
2, 1882) for the St. Vrain Basin and can be used in the water supply for the
mining. Also shown are some other pertinent water rights. In addition,
Southwestern has a water service agreement with the City of Longmont under
which Longmont provides water to Southwestern via a 14-inch tap. This source
can be used as a backup supply for filling water trucks for dust suppression.
Among the water rights currently owned by Southwestern are 152 units of
Colorado Big Thompson Project (CBT) water, which will have an average annual
yield of 114 acre-feet, plus Southwestern has another 130 units under option.
• The CBT units can provide water for dust suppression and irrigation from May
through October, then can be stored in one of the on-site reservoirs for dust
suppression during the remainder of the year. Potential storage sites include
Kimball Lake, Martin Marietta Cement Lake, and Pit A at Southwestern's plant
site; other ponds are anticipated at Dowe Flats once mining commences.
Kimball Lake has a storage capacity of ZO acre-feet and has an outlet to the
St. Vrain River. Its junior decreed water right in Case No. W-3011 could
provide water for augmentation. Martin Marietta Cement Lake has a storage
capacity of 36 acre-feet; and Pits A and C could have a combined storage
capacity of about 9,000 acre-feet when the mining creating these pits is
completed. Pit A is currently about 125 feet deep and has a capacity of
approximately 300 acre-feet of water. Southwestern also has a pending
application for a junior water right at Dowe Flats in Case No. 63CW374.
The total average annual yield of Southwestern's ownership of first
adjudication water rights is 320 acre-feet, and the total firm yield is 81
acre-feet. When the current CBT ownership of 152 units is included, the
average annual yield is 434 acre-feet and the firm yield is 233 acre-feet. An
additional 167 acre-feet of firm yield are available from the optioned water.
The estimated maximum depletions, however, are only 70 acre-feet for dust
suppression; 5 acre-feet for evaporative losses; and 50 acre-feet for the
establishment irrigation of trees and shrubs during reclamation.