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can have very significant adverse impacts on the forest units in particular. But cottonwood is a <br />very tough plant. It has to be to live in this habitat. Cottonwood can adapt to small declines in <br />the water table as it frequently must when drought occurs. But if the water table is reduced by <br />five or ten feet by deep mining in the adjacent stream it is unlikely the forest will adjust to and <br />survive that much change. <br />It has been learned that where clay seams exist under the sand in these prairie <br />channels removal of the sand and exposure of the clay can actually improve the character of <br />the drainage by inducing large areas of herbaceous wetlands to develop. These capture <br />sediment and improve water quality as well as probably help stabilize the water table and <br />reduce peak flow intensities. <br />If the sand is removed, or even if it isn't removed, the valuable riparian forests can be <br />maintained if the stream corridor is protected from excessive grazing pressure. It appears that <br />cattle grazing is the main factor in preventing the reforestation of the riparian zone in the <br />valley. Intense cattle grazing basically eliminates the benefits of reproduction. The mitigation <br />areas were almost totally protected from grazing and not only does the herbaceous growth <br />flourish with that protection but woody vegetation redevelops at a rate and with a volume that <br />far exceeds anything that could feasibly be done by planting. Outside the protected areas <br />woody vegetation struggles to achieve a size where it could naturally "defend" itself against <br />cattle. Without protection few invaders will ever have a chance to become mature plants so <br />long as grazing is allowed to occur throughout the year. <br />It has also been learned that the dense herbaceous growth that develops on the exposed <br />clay seams after sand removal is fully capable of defending itself against the invasion of <br />noxious weeds from surrounding lands. The marked lack of noxious weeds or even non-noxious <br />weeds in the wetland units, even when living adjacent to land heavily infested with weeds that <br />could invade, indicates just how strong these wetland units have become in just a few years. <br />In the opinion of this author and based upon the evidence provided, it appears that the <br />purpose and intent of the wetland mitigation program has been more than achieved. In fact, <br />through this program a great deal has been learned that provides valuable information for <br />future management and utilization actions in this drainage. This information will not only be <br />useful to the permittee, but also useful to the Corps of Engineers and, most important of all, <br />the State of Colorado who is the landowner. <br />Final Recommendations <br />Following are a number of recommendations and suggestions to maintain or improve <br />the quality of the land and its vegetation cover. These are general recommendations regarding <br />the overall management of this property and do not necessarily pertain to the wetland <br />mitigation efforts or the full gamut of the Corps of Engineers' interests in the property. <br />Coal Creek Wetlands and Wetland Mitigation DA Permit 198811488 August 2003 Page 21 of 23 <br />