Cumulative impacts to riparian habitat in the Malibu Creek watershed (California)

One of the most commonly cited criticisms of the Clean Water Act Section 404 program is the U.S. Army Corps of Engineers' failure to effectively manage cumulative impacts. Several factors contribute to this phenomenon, including the agency's case-by-case permitting approach, workload demands, and the lack of effective analytical methods. The goal of this dissertation is to remedy the latter deficiency by developing cumulative effects assessment methods for wetlands regulation; and applying them in the Malibu Creek watershed.; Application of the methods indicates that the Malibu Creek watershed contains large tracts of high quality riparian habitat, but has experienced substantial degradation. Major contributors to riparian habitat degradation include channelization, recreation facilities (i.e., parks, golf courses), and lake/reservoir construction. These findings are used to develop a riparian restoration plan for the watershed.; A number of policy and management recommendations emerge from these analyses: (1) Southwestern riparian ecosystems are not well protected by federal law. Congress should broaden the scope of Section 404 to better protect these valuable resources. (2) The Corps of Engineers should make a concerted effort to better manage cumulative effects. Toward this end, the agency must remedy some of the factors that contribute to this shortcoming (e.g., emphasis on permit processing). (3) The Corps of Engineers should expand its scope of analysis vis-à-vis cumulative effects to include all impacts, regardless of when they occurred or whether they were permitted. (4) The Corps of Engineers and EPA should work together to develop meaningful cumulative impact criteria. (5) Stakeholders should work together to develop an aquatic resource management plan for the Malibu Creek watershed. Goals should include protecting high quality riparian areas from development; better managing riparian areas to minimize impacts; restoring natural processes; and acquiring key properties for habitat restoration.