Chabot Dam Seismic Upgrade Spec 2107 Board of Directors March 8, 2016
Project Location NAB Hayward Fault Chabot Dam
Project Location North Chabot Reservoir 10,350 Acre-Ft Outlet Tunnel Hayward fault zone Chabot Dam
Chabot Dam and Outlet Works Outlet Works Outlet Tunnel 30 Blowoff Chabot Dam
Chabot Dam and Outlet Works Chabot Dam Outlet Works
Dam Constructed in 1875 Anthony Chabot (1813 1888) April 1888
Project Need Division of Safety of Dams (DSOD) asked District to evaluate impacts from a Mw 7.25 earthquake on the nearby Hayward fault Findings: Earth dam could settle and displace several feet downslope Outlet works could collapse and become inoperable DSOD directed District to construct seismic upgrades to earth dam and outlet works
Earth Dam Seismic Upgrade Max Lake Level Expected displacements due to Mw 7.25 earthquake Existing Dam Max Lake Level 100-ft wide CDSM buttress to reduce seismic displacements Dam After Upgrade
Cement Deep Soil Mixing Buttress at Toe of Dam
Outlet Works Retrofit Existing Outlet Works Outlet Works After Retrofit Max Lake Level
Temporary Park Closures
San Leandro Creek Flows No impacts to creek during construction Will maintain current flows of 80 gpm (min) EBMUD working with CDFW to develop long-term strategy for fish flows in creek DWR Prop 1E (Stormwater Management) Grant received -$5 million; reservoir captures storm water runoff, reduces sediment to creek 30 Blowoff Discharge (max) San Leandro Creek below Dam
Unsuccessful attempt at a Pilot Project Labor Agreement PLA negotiating principles approved by Board on December 9, 2014 PLA approved by Board on January 12, 2016 Alameda County Building Trades Council declined to execute the negotiated PLA because it required: All qualified contractors and subcontractors to be permitted to bid and be awarded work regardless of MLA signatory status (Public Contract Code 2500) Waiver of union initiation fees upon request for contractors core workers who are not offered or who do not seek union membership
Project Phases and Dates Board certified EIR June 10, 2014 District finalized design December 2015 Advertised contract January 5, 2016 District approved Pilot PLA January 12, 2016 Opened bids February 10, 2016 Total of 6 bids; lowest effective responsible bidder is DMZ Builders, Inc. at $11,998,600
Next Steps Action Date Contract Award March 8, 2016 Issue Notice to Proceed April 2016 Close Parks/Start Field Work May 2016 Chabot Dam Earthwork Jun to Nov 2016 Outlet Works Retrofit Dec 2016 to May 2017 Contract Completion/Open Parks Summer 2017
Water Supply Board Briefing Water Operations Department March 8, 2016
Water Supply Briefing California Water Supply Current Water Supply Water Supply Projections Water Supply Schedule 2
California Water Supply
California Water Supply Snow Surveys March 2015 March 2016 Michael Macor. SF Chronicle Rich Pedroncelli, AP DWR allocations are 30% for CY16 4
California Water Supply Automated Survey - Snow Water Equivalents Automated Snow Measurements Snow Water Equivalents Year % of Normal on March 7 2015 18% 2016 82% Snow station surveys conducted around March 1, 2016 Manual readings confirm preliminary automated measurements 5
California Water Supply Reservoir Storage March 7 March 7, 2016 Storage Average Storage on March 7 Storage on Feb 21 6
California Water Supply Folsom Lake Flood Releases 7
Current Water Supply 8
Current Water Supply Mokelumne Precipitation 11.45 10.9 Rainfall Year 2016 Average 2.06 5.00 5.83 2.56 0.45 0.08 0.06 9
Current Water Supply East Bay Precipitation Rainfall Year 2016 Average 7.51 5.02 0.92 4.21 1.94 0.04 0.03 0.03 0.01 10
Current Water Supply Precipitation & Snow Add current photos East Bay As of 3/7/2016 Cumulative Precipitation % of Average East Bay Watershed 19.71 95% Mokelumne Basin 4-Station Average 38.39 108% Caples Lake Snow Depth 78 105% Caples Lake Snow Water Content 28.8 106% 11
Current Water Supply Caples Lake Snow Depth 90 80 70 60 2015-16 2014-15 Historical Average Snow Depth (in) 50 40 30 20 10 0 O N D J F M A M J Date 12
Current Water Supply Gross Water Production 300 3-Year Avg of FY 2005-2007 FY 2016 FY 2013 (184 MGD) FY 2016 Operational Estimate (149 MGD) 250 gross water production (mgd) 200 150 100 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun
Current Water Supply Water Savings Savings Rate (2013 Baseline) March 8, 2015 March 7, 2016 June 1, 2015 Feb 29, 2016 23% 24% 14
Current Water Supply Reservoir Storage As of 3/7/16 Current Storage Percent of Average Percent of Capacity Pardee 181,480 AF 102% 92% Camanche 125,100 AF 45% 30% East Bay 127,160 AF 93% 84% Total System 433,740 AF 73% 57% 15
Water Supply Projections
Water Supply Projections (Runoff Projections as of March 8, 2016) Forecast Annual Runoff Total System Storage (on Sept 30, 2016) No Rain To-Come 490 TAF 420 AF 95% Exceedance (9.5 of 10 years are wetter) 90% Exceedance (9 of 10 years are wetter) 50% Exceedance (5 of 10 years are wetter) 10% Exceedance (1 of 10 years is wetter) 610 TAF 515 TAF 640 TAF 535 TAF 740 TAF 630 TAF 980 TAF 630 TAF Average Year 745 TAF 630 TAF 17
Proposed DMP Guidelines Demand Management Program Guidelines Include four stages of drought Allow for rationing >15% in extreme situations Stage Projected TSS (TAF) Quantity of CVP and Supplemental Supply Needed (Acre-Feet) District-Wide Water Use Reduction Goal 0 Normal 500 or more 0 Wise water use 1 Moderate 500-450 0 Voluntary up to 15% 2 Significant 450-390 0-35,000 Voluntary up to 15% 3 Severe 390-325 35,000-65,000 Mandatory up to 15% 4 Critical <325 >65,000 Mandatory 15% 18
Water Supply Projections Mokelumne Precipitation Rainfall Year 2016 Wettest of Record 87.3 (RY83) RY 2016 To-Date 38.39 10% Exceedance Median Average 48.3 90% Exceedance Driest of Record 23.0 (RY77) 19
Water Supply Projections Precipitation Comparison 50 Precipitation (in) - Recent Years 45 Historical Avg 48.3 MEDIAN 49 40 DRY 45 35 31.1 34.0 30 6.6 27.3 29.2 25 20 Remainder 15.4 7.0 6.7 Through Mar 7 38.4 15 27.4 20.3 22.5 10 Through Mar 7 15.7 5 0 2012 2013 2014 2015 2016 20
Water Supply End of September Storage MEDIAN 630 TAF 30 TAF Encroachment DRY 535 TAF 25 TAF SS 15 TAF Conservation 40 TAF SS 45 TAF Conservation 21
Water Supply Projections Weather Forecast 22
Water Supply Projections 10-Day NOAA Precipitation Probability Estimate ~70% Chance of Above-Normal Precipitation In the Mokelumne Watershed 23
Water Supply Projections 14-Day NOAA Precipitation Probability Estimate Likely Normal Precipitation In the Mokelumne Watershed 24
Water Supply Projections NOAA Precipitation Probability Estimate through May 33 to 40% Increased Chance of Above- Normal Precipitation In the Mokelumne Watershed 25
Water Year 2016 As of March 6, 2016 Mokelumne River basin runoff is 202 TAF Projected end of water year storage is 535 630 TAF (90% - 10% exceedance) Mokelumne River watershed season to date precipitation is 108% of average East Bay watershed season to date precipitation is 95% of average Precipitation accumulation season 74% complete (26% remaining) 26
Water Year 2016 Water Supply Schedule Date Feb 2 Feb 23 Early March Mar 20 March to April April 1 April 26 Activity DWR February Snow Survey Drought Financial Impacts DWR March Snow Survey USBR Initial Allocation Water Supply Updates Continue public outreach DWR April Snow Survey Water Supply Availability and Deficiency Report Consider change in Drought Stage 27
St. Patrick s Day 2016 Luck? Total System Storage
WATER SUPPLY ENGINEERING DAILY REPORT RESERVOIR STORAGE AND ELEVATION WATER SURFACE STORAGE MAXIMUM CAPACITY Elevation +Gain +Gain Elevation Storage Release Spill MOKELUMNE Feet -Loss Ac-Ft -Loss Feet Ac-Ft Cfs Cfs Pardee 560.04 1.74 181480 3640 567.65 197950 1320 0 Camanche 184.69 0.81 125100 3100 235.5 417120 205 0 EAST BAY Briones 574.2 0.23 59120 170 576.14 60510 0 0 Chabot 219.55 0.72 7910 200 227.25 10350 0 0 Lafayette 443.59 0.29 3570 30 449.16 4250 0 0 San Pablo 297.96 0.79 26740 530 313.68 38600 0 0 Upper San Leandro 448.21 1.08 29820 670 459.98 37960 0 0 Total East Bay Res. 127160 1600 151670 TOTAL SYSTEM STORAGE 433740 8340 766740 DISTRIBUTION SYSTEM MOKELUMNE SYSTEM DISTRIBUTION RESERVOIRS Storage Operating MG Flow Conditions MG Capacity Line 1 11.1 SHUTDOWN Today 349 720 Line 2 20.2 THROTTLE Total Previous Day 353 Line 3 48.6 THROTTLE Total Change -4 TOTAL 79.9 124 Cfs FSCC to MOK AQUEDUCTS (Measured at Brandt), MG WATER PRODUCTION Million Capacity Mok 1 0 AND DEMAND Gallons MGD Mok 2 0 Lafayette WTP 0 25 0 MG Orinda WTP 55 190 RIVER FLOWS AND RELEASES Cfs San Pablo WTP 10.2 30 Mokelumne River Natural Flow 4234 Sobrante WTP 13.2 50 Pardee Reservoir Inflow 3187 Upper San Leandro WTP 14.9 45 Pardee Release to Camanche Res. 1320 Walnut Creek WTP 25.4 90 Pardee Release to JVID Camanche Release to Mokel. River 0 205 TOTAL SURFACE PRODUCTION 118.7 430 Miscellaneous(Estimated) 0.4 PG&E CO. STORAGE (Acre-feet) TOTAL WATER PRODUCTION 119.1 Maximum Change in Distribution System -4 Storage Change Capacity Wash Water from Distribution Sys. 1 Old Reservoirs 11663 11 26560 SYSTEM DEMAND 121.9 Salt Springs Res. 42112 1618 141857 East-of-Hills Demand 23.5 Lower Bear Res. 20850 448 52025 West-of-Hills Demand 98.4 Total 74625 2077 220442 RAW WATER TRANSMISSION Ac-ft PRECIPITATION (Inches) INPUT DRAFT THIS YEAR AVERAGE YEAR Briones Res. 0 0 San Pablo Res. 0 75 STATION This Season Season Season U. San Leandro Res. 0 49 Today Month to-date to-date Total USL WTP 1.46 4.79 22.16 19.62 25.33 TOTAL 0 124 Orinda WTP 0.88 4.76 22.32 24.75 32.06 REMARKS Lafayette Reservoir 0.69 3.62 17.26 22.01 28.18 WID Canal Diversion = 62 cfs Walnut Creek WTP 0.46 3.67 16.4 18.22 23.02 Mokelumne River below WID = 166 cfs Camp Pardee 1.1 3.72 19.76 15.77 21.56 Salt Springs P.H. 0.33 4.56 38.03 33.19 45.51 CAPLES LAKE (7,830 FT) DATA PG&E data as of 4:00 pm previous date. All other data as of midnight. Snow Depth WTP capacities are sustainable rates. Water Content Today 78 Inches 28.8 Inches EAST BAY MUNICIPAL UTILITY DISTRICT AQUEDUCT DELIVERIES Average 74 Inches 27.2 Inches Monday, March 7, 2016