Laserfiche WebLink
<br />t,. .-4 <br /> <br />'0 u ~ '{ 1 ~ <br /> <br />- <br /> <br />OPPORTUNITIES FOR ECOLOGICAL IMPROVEMENT ALONG THE LOWER <br />COLORADO RIVER AND DELTA <br /> <br />Mark K. Briggs1 and Steve Cornelius2 <br /> <br />Abstract: The lower Colorado River mainstem and delta have been <br />severely damaged by a variety of human-related activities, including river <br />impoundment, agriculture, water diversions, introduction of exotic <br />plants, and groundwater pumping. In some areas the native wetland <br />habitat that formerly dominated this region has disappeared completely. <br />Nevertheless, there are areas where significant wetland habitat persists as <br />a result of incidental circumstances or purposeful restoration actions. <br />These areas provide important conservation and restoration <br />opportunities. <br />In this investigation, nine restoration efforts along the lower Colorado <br />River from Parker Dam to the delta region were evaluated to learn how <br />lessons from these experiences can benefit future ecological recovery <br />efforts. In addition, investigators assessed the general ecological <br />condition of this reach to identify critical native wetland plant <br />communities and recommend strategies for protecting these areas in the <br />future. <br />It is apparent that wetland ecosystems in both the delta and the mainstem <br />would benefit if effluent waters were allocated to support wetlands, <br />rather than allocated to evaporative basins. Other important strategies for <br />improving the ecological condition of the river should include altering <br />reservoir releases, improving the effectiveness of revegetation efforts, and <br />developing bi-national, collaborative approaches involving local <br />communities and landowners to identify and carry out projects that <br />benefit both them and the ecological condition of the river. <br /> <br />PROJECT OBJECTIVE <br />The overall goal of this investigation is to identify opportunities and strategies for <br />improving the ecological condition of the lower Colorado River. The focus of this effort <br />is the lower portion of the Colorado River, which includes the mainstem of the river <br />from Parker Dam to the delta as well as the delta itself. This effort has three principal <br />objectives. First, the effectiveness of past recovery" efforts along the lower Colorado <br />River (from Parker Dam to the river's delta) were evaluated so that lessons gained from <br />these experiences can be applied to future ecological recovery activities. Second, the <br /> <br />1 Director of Research, Sonoran Institute, Tucson, Arizona. <br />2 Director of Borderlands Program, Sonoran Institute, Tucson, Arizona. <br />. Three terms are often used to describe efforts for improving the ecological condition of a damaged <br />area: restoration, rehabilitation, and reallocation (Bradshaw 1988; Aronson et aI. 1993). Each term <br />carries with it a specific meaning with regard to the effort's intended endpoint. To avoid confusion, this <br />report will use the generic term "recovery" when the objective of a particular project was not stated or <br />unclear. <br /> <br />Page 1 <br />