EVEREST June, 2013 - California Department of Boating and ...

Orange County Coastal Regional Sediment Management Plan
deposition of sediments is also restricting the storage capacity behind the dam. Excessive
sedimentation in, and upstream of, Prado Basin negatively impacts habitat, water conservation
efforts, and civil infrastructure.
Goal
The goal of the proposed project is to demonstrate the effectiveness of sediment removal from
the Prado Basin and re-entrainment of sediment into the lower Santa Ana River; while
protecting civil infrastructure and improving water conservation and ecosystem restoration.
The completed project will include data, conclusions and recommendations that examine the
feasibility of a long-term program for ongoing sediment management of the Prado Basin and
lower Santa Ana River.
Benefits In/Above Prado Basin
1. Increase water storage for flood control
2. Increase water storage for water conservation
3. Slow or reverse sedimentation rates behind the Prado Dam, thereby increasing the
useful life of Prado Dam
4. Reduced sedimentation trends that threaten infrastructure (e.g., wetlands, roads and
bridges, most notably River Road Bridge)
5. Increased edge under-story riparian habitat
Benefits Below Prado Dam
1. Stop and/or reverse streambed incision, thereby halting embankment erosion which
results in wildlife habitat destruction
2. Providing replenishment sediment to stop streambed incision and protect infrastructure
(e.g., SARI Line, CA 91 Freeway)
3. Stop and/or reverse riverbed armoring, which decreases the capacity of Orange County
Water District’s groundwater recharge facilities
4. Provide replenishment sediment to coastal communities
Everest International Consultants, Inc. D.3