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David K. Clark, PE AFC15 David K. Clark, PE THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA LAKE SHASTA LAKE OROVILLE Bay-Delta LOS ANGELES AQUEDUCTS (City of Los Angeles) COLORADO CALIFORNIA RIVER AQUEDUCT AQUEDUCT (State of Calif.) (Metropolitan) LOCAL SUPPLIES, RECYCLING, GROUNDWATER & CONSERVATION Background Seismic Preparedness Seismic upgrade of facilities Seismic vulnerability assessments Emergency response Collaboration with External Agencies Conclusions 1.7 billion gallons/day average 6 counties, 18 million residents Comprised of 26 member public agencies Imports Colorado River & State Water Project supplies Operates 5 water treatment & 16 hydroelectric plants Maintains 830 miles of pipeline & 9 reservoirs Biennial budget for FY 2014-16 is approximately $3 billion Comprehensive Reliability Strategy Water System InfrastructureInfrastructure System EmergencyEmergency Supply Capacity ReliabilityReliability FlexibilityFlexibility ResponseResponse Seismic Preparedness 1. Seismic Upgrade of Facilities 2. Vulnerability Assessments 3. Emergency Response 4. Collaboration w/External Agencies Scope: Buildings & Structures Dams & Reservoirs Geotechnical Hazards Drivers: Code Changes Increased Knowledge Approach: Re-assess as necessary Upgrade as required Use latest codes Use site-specific data Expect same performance as for new facilities Example of Code Changes (Weymouth Water Treatment Plant) Year Design Peak Ground Acceleration (PGA) UBC 1933 0.1g UBC 1958 0.1g* UBC 1991 0.4g IBC 2009 0.52g IBC 2012 0.71g *Estimated value, PGA was not specifically defined in early versions of UBC Lake Mathews Outlet Tower 1940 2003 Projects at the Diemer Water Treatment Plant Chemical Facility East Filter Building Foundation Filter Outlet Conduit Seismic Upgrade Slope Stabilization Admin Bldg East WW Tank Seismic Upgrade & Foundation North Slope Remediation West Filter Building Seismic Upgrade WWRP Slope Stabilization Completed West WW Tank South Slope Stabilization Finished Water In Progress Seismic Upgrade Reservoir Foundation Planned West Pad Lower Feeder Slope Stabilization Relocation Evaluate impacts on regions & entire distribution system from earthquakes Steps Determine potential damage Estimate outage durations Identify potential mitigation strategies Example of Reliability Improvement Diamond Valley Lake Constructed on coastal side of major faults Can directly supply 4 of 5 treatment plants Provides emergency supply Example: Colorado River Aqueduct Tunnels Scope Model surface deformation on the So. San Andreas Fault System in the San Gorgonio Pass Evaluate impact of modeled surface deformation on the Colorado River Aqueduct Colorado River Aqueduct L A Aqueduct California Aqueduct Conveyance Systems Metropolitan CA DWR San Andreas Fault Los Angeles SAN BERNARDINO San Gorgonio Pass LOS ANGELES Colorado River Aqueduct RIVERSIDE ORANGE Diamond Valley Lake SAN DIEGO San Gorgonio Pass San Gorgonio Pass Redlands Lake Eagle Mountain Mathews Pumping Plant Palm Springs Hinds Pumping Transpressive Plant Stepover in So. Bombay Beach San Andreas Fault System (SG Knot) Vertical Deformation Comparison to Geomorphology Black arrows marking large drainage divides approximate broad, regional flexure s associated with crustal shorting at & near the stepover. Arrows show direction of plunge. (Yule & Sieh, 2003) Fault Crossings in San Gorgonio Pass Whitewater Tunnel No. 2 CRA Conduit, Siphon CRA Tunnel Faults Impact of Surface Deformation on Hydraulics (M7.8) Uplift results in less than 20% reduction in flow CRA Hinds Pump Plant VERTICAL 1 meter (3 feet) Flow Direction 60 km (35 miles) HORIZONTAL 4 meters DISPLACEMENT (12 ¾ feet) Tunnel Repair Workshop Workshop Goals Estimate time to restore operation based on worst-case scenario Failure within Whitewater Tunnel No. 2 Identify options to to reduce repair time Participants Geotechnical engineers Tunnel contractors Geologists Metropolitan staff Tunnel Repair Workshop Damage Scenario at Fault Crossing from 1 meter1 meter vertical M7.8 event vertical 4 meters horizontal Tunnel Repair Workshop Findings Tunnel can be repaired in 6 months Pre-planning recommended Pre-design repair elements Pre-qualify tunnel contractors Stockpile key materials Consider new access structure at tunnel’s west portal Repair Capability Goal Maintain in-house capability to repair 2 simultaneous pipeline breaks Heavy equipment Structural supplies Emergency contracts Pipe fabrication shop capacity Imported Water Supplies Seismic Resilience Water Supply Task Force • Assess three aqueducts as a whole • Develop mitigation options • Identify optimal response strategies • Prepare for joint emergency exercises Metropolitan recognizes the potential for water delivery interruptions from seismic events and is being proactive to identify and mitigate key risks As not all risks can be mitigated, robust emergency response capabilities are essential to overall system reliability Collaboration with other agencies supplying imported water to Southern California will increase the regions overall seismic resiliency Questions? Contact Information: David K. Clark Engineering Services Group Metropolitan Water District [email protected] (213) 217-6070 [email protected] (213) 217-7495 Status of Buildings and Structures Assessments Structures Requiring 311 (Pre-1990) Seismic Evaluation Rapid Evaluation 300 11 Completed Remain Rapid 108 Potentially 192 O.K. Evaluation Deficient Result Seismic 2 Funded for 21 requiring Upgrade 49 Upgraded 36 In Progress Detailed funding for detailed Evaluation evaluation 0 Related Detailed 21 Not Related to to Water Evaluation Water Delivery Priority Delivery Notes Goals Maintain continuous water deliveries following a major earthquake Minimize damage to facilities Protect building occupants Approach Provide regional storage, & support development of local supplies & storage Strengthen individual facilities to remain in continuous operation Maintain robust emergency response & repair capabilities to restore deliveries ASAP.
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