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Explore the comprehensive study on restoring ecosystem, conserving water, and managing sediment in Prado Basin. Learn about cost-benefit analysis, sedimentation issues, and proposed restoration measures for the basin’s sustainability.
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Prado Basin Feasibility Study Cost-Benefit Analysis Water Issues Committee March 14, 2018
Prado Basin Feasibility Study • Agreement with Army Corps established District as non-federal (local) sponsor • Feasibility Study includes • Ecosystem restoration • Water conservation (temporary stormwater capture) • Sediment management
Ecosystem Restoration Measures in Feasibility Study These are a range of features to enhance the environment, including: • Non-native plant removal • Non-native animal removal (aquatic species & feral pigs) • Sediment removal • Modifications to Chino Creek to restore riparian habitat
Sedimentation in Prado Basin • From 1941 to 2008, lost 25,000 acre-feet of storage below 505 ft elevation • 20,000 acre-feet remaining as of 2008 survey • Sedimentation in Prado Basin will essentially eliminate water conservation storage in 50 years if not addressed • Loss of 30,000 acre-feet per year of water
Sediment Management Measures • Capture sediment in general area of River Road bridge • Captured sediment is either: • Moved to storage sites away from the river channel, generally around perimeter of Prado Basin – accessible for future aggregate use or other beneficial re-use; or • Re-entrained into SAR below Prado Dam
Cost-Benefit Analysis Assumptions • Cost of firm untreated water purchased from Metropolitan and O&M for project inflates 3% per year • Annual capital cost is estimated based on a 5% interest loan over 50 years. • Increased storage space created by sediment management is utilized one time per year.
Cost Share between Corps & OCWD • Water Conservation: 100% OCWD cost • Ecosystem restoration: construction 65% Corps, 35% OCWD • O&M: 100% OCWD is standard • Can request federal cost share of O&M due to unique nature of sediment management costs (higher percentage of O&M relative to construction cost) • Exploring phased implementation of some project measures, such as sediment management measures
Next Steps • Reviewing cost increase to complete Study from Corps • Evaluate sensitivity to assumptions in cost benefit analysis • Release draft Feasibility Study report for public comments (includes draft EIR) • OCWD identify preferred alternative