Laserfiche WebLink
COAL CREEK RESOURCE • <br />Page 6 <br />r1 <br />U <br />Section E - Similar Situations: ~~~'S <br />' <br />' <br />,4ccording to the information I <br />ve collected, it <br />s not v <br />unusual for cottonwoods to retain a vigorous appearance for <br />several years after an injury or drop in the water table. <br />(Hike Scott, U.S. Fish & Wildlife Service, indicates that <br />along the Cache la Poudre some trees are taking as long as <br />Five to ten years to exhibit stress from mining activities. <br />The Sand Creek mining was done two years ago, so it's not <br />unusual for the cottonwoods to still appear normal. <br />Section F - Methods to Mitioate Impacts to Cottonwood Trees: <br />1. Proper Mining Setback - I think "locating a lateral tree <br />root by hand girtg and following it out" is impractical, (/ <br />;and, given the probable nature of the ground water, I think <br />this entire discussion is moot. <br />?. No Tree Islands - See above. <br />3. Tree Monitoring - "Since mining will only consume I/4 to <br />I/3 of a mile each year, there will be plenty of time to <br />monitor the health of the trees." If, as discussed above, <br />trees did not exhibit immediate signs of stress, mining <br />~~ould easily be two to five years along before "red flags go <br />up." Trees could be dying en masse for a distance of 1/2 to <br />l I/2 miles, or more, before anyone initiated mitigation <br />reasures. And how would mitigation help these trees? <br />}. Groundwater Monitoring - I think evidence of groundwater <br />conditions and behavior should be collected and made a part <br />of the application. This subject shoulfi not have-to rely on <br />hind sight to make the situation clear. <br />:iection G - Additional Mitigation Measures To Be Used: <br />:Item 1: Placing soil in mined-out areas may help raise the <br />water table, but this would depend on the nature of channel <br />gradient manipulations downstream. The profile of a channel <br />s~ith a stable bed and uniform alluvium usually parallels the <br />profile of the underlying ground water surface. If <br />:significant cuts were made in the channel downstream, we <br />could expect the profiles to be quite different. Ground <br />slater won't rise and be absorbed by fill materials unless <br />other hydraulic conditions are favorable. <br />:Item 3: There may be ways to harvest additional water for <br />use by trees, but I don't think the scenario przsented here (r <br />is one of them. <br />Item 4: Fertilizing of trees will probably n_ot result in ~ <br />much root development. Foliar application of a fertilizer <br />would probably just result in more top growth. Tree roots <br />