American River Watershed Investigation California

This appendix presents the real estate requirements for the selected plan to provide critically needed flood protection for urban areas along and adjacent to the lower American River in the vicinity of Sacramento, California. The Corps' authorization for its one-year reconnaissance study was included in the 1987 Appropriations Act. Authorization for additional study was included in committee language accompanying the Fiscal Year 1988 Continuing Appropriations Act (Public Law 100- 202, dated December 22, 1987).

This reconnaissance report has been prepared by the Sacramento District Corps of Engineers in accordance with the 1987 Appropriations Act. The report describes studies of alternative measures for flood control in the American River Watershed predicated on the assumption that Auburn Dam as previously authorized will not be constructed. Studies have focused on (1) definition of flood problems in the watershed, (2) formulation and evaluation of alternative plans for detailed development in future feasibility studies, (3) development of a management plan for the feasibility studies, and (4) identification of a non-federal sponsor for the feasibility study. The primary study area included the lower American River between Nimbus Dam and the Sacramento River and the Natomas area and vicinity of Sacramento. Other areas considered were the American River and its tributaries upstream from Nimbus Dam, Sacramento River from the American River upstream to the Sacramento Weir, and Yolo Bypass and its immediate tributaries and distributaries. Major flood control facilities and features in the study area are 400,000 acre-feet (ac-ft) of seasonally dedicated space in Folsom Reservoir, located about 25 miles east of Sacramento, and a complex system of levee and channel improvements downstream along the American and Sacramento Rivers and in the Yolo Bypass.

To insure that the planning studies addressed all potential problems, the Corps maintained continuous coordination with local sponsors, agencies affected by the project, and agencies directly involved in project studies. Formal coordination included presentations at meetings of the Executive Committee. The most extensive coordination, however, was accomplished through the Study Management Team meetings. The Corps initiated these meetings in February 1988 to discuss study results by the various agencies involved. The meetings encouraged the interchange of ideas and discussion of problems, and provided an opportunity for participation in project planning by the City and County of Sacramento and agencies not otherwise directly involved in the studies.

Our analysis of project impacts on fish and wildlife resources is based on a literature review; personal communication with recognized experts; field investigations and surveys; preliminary engineering and other information provided by the Corps; and a projection of future conditions using current land-use information and analysis provided by the Corps. Our analysis will not remain valid if the project, the resource base, or anticipated futures change significantly. This report is accompanied by separate substantiating reports for the three major segments of the American River Watershed Investigation: Auburn area, Lower American River area, and Natomas area.