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~~ Divisional Correspondence Only STATE OF COIARADO D I V I S I O N O F W I L D L I F E Department of Natural Resources TO: Dave Weber FROM: Susan Werner,a,~ DATE: December 19. 1994 SUBJ: Cooley Gravel -Morrison Quarry Amendment 4 This amendment would allow an additional 50 acres of surface disturbance and would also allow the applicant to mine deeper. This deeper mining will disrupt some surface drainage. The land between the limits of mining and the limit of disturbance will remain undisturbed except for access. Visual impacts will be minimized by the maintenance of a ridge along the east edge of the quarry. The applicant estimates that 2 million tons of gravel will be produced annually over the next six years. Reclamation will follow the downward excavation and will consist of backfill, topsoiling and revegetation. The applicant's plans call for the revegetation to mimic the predisturbed vegetation. Evergreen trees will be concentrated on north facing slopes. The slopes will be hydroseeded with 48 pounds per acre of native grass seed, and shrubs and trees will be transplanted Prom nurseries. Irrigation will take place for three years and plants will then be weaned to depend on natural watering. It appears that the reclamation plan is sound, and if all goes as planned, the resulting habitat will be comparable to premining conditions. Because noxious weeds have become a major threat to Front Range wildlife habitat, I was concerned that this aspect of reclamation had been ignored in this plan. When I reviewed the document a second time, I found that the applicant plans to monitor the reclamation effort over five years, and will spot treat any patches of weeds that get established on the disturbed area. This seems to address concerns about noxious weeds. Because the new mining efforts are going to be significantly deeper than past practices, dewatering will be needed. If there is any possibility of these containing toxic compounds, water quality needs to be closely monitored. Documentation provided by the applicant indicates that no water quality issues are anticipated in these reservoirs, however they suggest further testing. The plan states that the reservoirs have not undergone final design. The plan also states that the City of Morrison will likely be a partner in water storage contracts. If there is any possibility that these reservoirs might at some future date support a fishery, the Division of Wildlife should be involved in the design. If high quality fish habitat can be designed before construction, a high quality fishery often results. In general, it seems that Cooley has done an admirable job of reclamation in the past, and I detect no glaring issues in the reclamation portion of this amendment. Let me know if you can think of any additional ways this plan needs to be examined. Thanks!