UPPER NEWPORT BAY ESTUARINE ENHANCEMENT

Client: U.S. Army Corps of Engineers, Los Angeles District

Upper Newport Bay, one of the largest remaining wetlands in Southern California, provides habitat for a number of threatened and endangered plant and bird species. During the past forty years, concern has grown over the long-term health of the estuarine environment. Of particular importance is the impact of increased sedimentation from the 118 square mile watershed of San Diego Creek. Coastal Frontiers was engaged by the U.S. Army Corps of Engineers to assist with the preparation of both Reconnaissance and Feasibility studies for environmental enhancement.

Study Tasks and Findings

• Predict the changes that would occur over the next 50 years if no mitigative measures were taken - a course of action found to produce unacceptable sedimentation within the Upper Bay

• Evaluate the costs and benefits of the following measures: channel dredging, sediment basin expansion, dike segmentation, mudflat creation, and relocation of a man-made island that provides habitat for the Least Tern

• Develop six alternative plans to mitigate sediment accumulation while enhancing the estuarine environment using various combinations of the measures listed above

Based on the success of the Reconnaissance Study, Coastal Frontiers was asked to provide detailed technical analyses in support of the "Upper Newport Bay Ecosystem Feasibility Study" that followed. The resulting plan of improvement has been implemented successfully over the past decade.