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~ • • 3) Optional ground water cutoff/slurry wall. If this option is selected, and the lake to be formed through mining ends up being a fluctuating lined storage reservoir rather than a stable groundwater lake as originally planned, considerable wildlife habitat value may be lost, depending on how the storage reservoir were to be managed. For instance, in 1487 we suggested that the reservoir, when reclaimed, have undulating shorelines to encourage more wildlife use of the lake edges. This was agreed to in the approved plan. Undulating shorelines in a fluctuating reservoir may have no beneficial effect at all if the water level is below full most of the year. Similarly, development of shoreline wetland vegetation may not occur if the shoreline fluctuates greatly due to changing storage levels. The current plan calls for several shallow water areas to be intentionally left around the lakes, presumably for wildlife habitat enhancement or mitigation. These would serve an excellent purpose in a stable-water level lake. In a fluctuating reservoir they might be useless if they were dry a large part of the year. Our 1987 comments by District Wildlife Manager Dave Lovell were made with the specific understanding that property was to "be reclaimed for its wildlife and fisheries value and turned over to a municipal agency". This amendment application at least presents the option that these goals be abandoned and the area be instead managed as a fluctuating water storage reservoir. If that occurs, we would have concerns with regard to the loss of habitat quality along the South Platte River riparian area. Therefore, if the option of lining the reservoirs for water storage is selected, we make the following two mitigation suggestions: - That at the western edge of the northernmost take, an area be preserved from groundwater lining which is somewhat larger than proposed in the current application. The enclosed map shows the suggested new line. Note that we are not suggesting that mining not take place west of our line, just that the slurry wall not be placed so far west. Thus, we envision a riverside lake/wetland area outside the slurry wall, - That at the western edge of the two southern-most lakes, the slurry wall be moved farther east so that instead of only having about ]00' between the storage reservoir and the river, a zone of 250' is instead left. As above, we have no objection to mining occurring in this 150' wide additional strip, but suggest that it be backfilled so that it ends up being either ashallow-water wetland strip or replanted as a zone of cottonwood/willow vegetation which enhances the riverside area for wildlife. We feel that these two measures should serve to reduce impacts to the riverside habitat area which might no longer be mitigated by a stable-water lake situation. I hope this information is helpful. Please let me know if you have any questions.