Much of the work included accommodating oil field development within the planning footprint and guiding the future abandonment and remediation of the oil fields in the future. In addition to work directly on the EIR/EIS, Catalyst staff provided extensive studies evaluating aquatic habitat, populations of selected aquatic species, and preparing mitigation approaches to offset impacts related to special status aquatic species within the project area. These studies focused on unarmored threespine stickleback, arroyo chub, and Santa Ana sucker and included a review of existing literature regarding these species within the Santa Clara River watershed, conducting biological habitat assessments and presence/absence surveys along the Santa Clara River and tributary drainages between Interstate 5 and the Los Angeles/Ventura County line, and preparing a report summarizing the study findings, potential impacts to aquatic habitat and these species, and mitigation measures to minimize impacts.
The impact analysis involved developing significance criteria for unarmored threespine stickleback and analyzing hydraulic model results for the proposed project and project alternatives to determine potential impacts relative to each alternative. In addition, we also conducted hydrologic studies in Middle and Potrero canyons to assist in project planning. The activities included collecting monthly surface water flow data and water level data to determine seasonal variability in surface water flows within these canyons. The surface water hydrology/flood control section and the geomorphology/riparian resources section characterize and evaluate potential project impacts along the Santa Clara River and tributaries.