Design Oversight Group Workshop May 28, 2014 1
Agenda 1. Introductions/Welcome 2. Meeting Purpose 3. Matilija History and Updates 4. TAC Activities and Consultant Selection Process 5. URS/Stillwater Team Introduction 6. URS/Stillwater Project Update 7. Closing 2
Introductions/Welcome 3
Meeting Purpose 4
Matilija History & Updates 5
Matilija History & Updates Recent Timeline: 6
TAC Activities & Consultant Selection Process 7
URS/Stillwater Team Introduction 8
Consultant Team Introduction 1. Team Background & Experience 2. Team Structure & Key Leads 3. Current Scope of Work 4. Schedule & Milestones 9
Consultant Team – Background & Experience 1. URS Broad Expertise a) Full service engineering and environmental b) Worldwide projects/experience c) Long history in California 2. URS Team Specialized Experience a) Dam design, management & DSOD b) Dam removal/modification (e.g. San Clemente, Searsville, Elwha, Boardman River, etc.) 3. Stillwater Sciences Specialized Experience a) Geomorphology & Sediment Transport b) Sediment Dynamics i. Dam Removal (e.g. Marmot, Klamath, Patapsco River) ii. Water diversion (e.g., Alameda Ck, Sacramento R., Santa Clara R.) 4. Other Consultants: Dennis Gathard 10
Consultant Team – Key Leads 1. Seth Gentzler, PE (Project Manager) Proven leadership on San Clemente, Searsville, – Napa-Sonoma Marsh and San Joaquin projects 2. John Roadifer, PE (Task 1 Lead) 28+ years of Geotechnical, Design and Construction – Experience 3. Derek Booth, PhD, PG, PE (Task 2 Lead) 30+ year career as a geomorphologist in the field of – river dynamics; UCSB Adjunct Professor 4. Yantao Cui, PhD Renowned expert it hydraulic and hydrologic – analyses, sediment transport modeling, and geomorphic assessment 5. Craig Smith, PE (Task 3 Lead) Over 26 Years of Experience in Water Facilities – Design and Construction 11
Consultant Team – Team Structure 12
Consultant Team – Team Structure 1. Benefits to Client/Stakeholders a) Proven industry expertise in issues surrounding dam removal b) Familiarity with site and stakeholders c) Redundancy across all staffing levels for dam removal and river function/restoration 13
Consultant Team – Current Scope of Work 1. Task 1: Dam Removal Plans and Cost Estimates a) Task 1.1: Background Review & Concept Matrix b) Task 1.2: Initial Options Screening c) Task 1.3: Full Dam Removal Concepts Evaluation 2. Task 2: Sediment Analysis a) Task 2.1: Hydrologic Assessment b) Task 2.2: Sediment Characterization c) Task 2.3: Initial Options Sediment Analysis d) Task 2.4: Full Dam Removal Sediment Analysis 14
Consultant Team – Current Scope of Work 3. Task 3: Robles Diversion Mitigation a) Task 3.1: Background Material Review b) Task 3.2: Hydrologic Assessment for Water Supply c) Task 3.3: Robles Mitigation Concept Evaluation 15
Consultant Team – Current Scope of Work 3. Budget Restrictions on Scope a) Removal of interim notch analysis b) Reduction in study area for technical analysis c) Reduction in number of options/concepts d) Reduction in number of face-to-face meetings 16
Consultant Team – Schedule & Milestones Initial Screening Concepts Evaluation 17
URS/Stillwater Project Update 18
Project Update Recent & Ongoing Work: 1. Sediment Characterization 2. Hydrologic Analysis and Scenarios 3. Background Review & Concept Matrix Development 4. Sediment Transport Model Setup 19
Sediment Characterization & Hydrologic Analysis 20
Background Review & Concept Matrix 21
Background Review Task 1.1 – Background Review & Develop Concept Matrix 1. Objectives: a) Review background documents, data and models b) Identify pertinent data gaps c) Summarize previous concepts considered d) Identify new concepts that merit consideration 22
Background Review 1. Key Documents/Info. a) GIS/AutoCAD/Models b) USBR Appraisal Study (2000) c) USACE Feasibility Study (2004) d) EIS/EIR e) Fine Sediment Study Group Documents f) Design Oversight Group Documents 23
Background Review 1) Library organization 24
Background Review 1) GIS Data - Topo 25
Background Review 1) GIS Data - Features 26
Background Review 1) Casitas MWD - organization 27
Background Review 1) Casitas MWD – monthly & annual data 28
Background Review 1) Sediment & hydraulic modeling tools 29
Concept Matrix Overview Key References Summary: 1. Appraisal Report (USBR 2000) 2. Feasibility Study (USACE 2004) 3. Upstream Sediment Disposal Areas (USA; USACE 2010) 4. Fine Sediment Study Group Final Report (FSSG 2011) 5. Double Barrel Bypass (Stoecker 2011) 30
Concept Matrix Overview Concept Summary Categories: 1. Fine Sediment 2. Coarse Sediment 3. Casitas Water Diversion 4. Downstream Flooding 5. Beach Replenishment 6. Construction & Cost Information 31
Concept Matrix Overview Previous Concepts – Appraisal Study (2000) Detailed Technical Analysis (Previously Documented) ID Concept Name General Description Reference Fine Sediment Coarse Sediment Casitas Water Diversion Sediment moved to the right side of the reservoir and stabilized/restored. River Approx. 400 AF/yr less yield for Casitas MWD Move Sediment Upstream channel graded and restored on left side of Appraisal Report Accumulated sediment is removed from the river system by with dam removal. High flow sediment AP-Alt. 1A of the Dam and Stabilize stabilizing onsite. No sediment modeling of this alternative. reservoir. The dam would be completely USBR 2000 bypass at Robles Diversion to flush chronic (Alt. 1A) removed in parallel with the sediment sediment. excavation/placement. Partial dam removal with a fish ladder over the lowered dam. Sediment moved (down Partial Dam Removal & Accumulated sediment is removed from the river system by AP-Alt. 1A to revised dam elevation) to the right side of Appraisal Report Move Sediment Upstream Similar to AP-Alt. 1A stabilizing onsite. No sediment modeling of this alternative. - Future the reservoir and stabilized/restored. River USBR 2000 of the Dam and Stabilize channel graded and restored on left side of reservoir. Coarse material (accumulated) removed from the river system. Fine material (accumulated) Material would be excavated and removed from the river system. Sediment would be excavated and hauled hauled to either a downstream Approx. 400 AF/yr less yield for Casitas MWD Move Sediment to a Site or Material would be excavated and downstream (ocean or other site) by truck. Appraisal Report permanent disposal site, with dam removal. High flow sediment AP-Alt. 1B Sites Downstream by hauled to either a downstream The dam would be completely removed, but USBR 2000 downstream temporary disposal bypass at Robles Diversion to flush chronic Trucking (Alt. 1B) permanent disposal site, in stages. site, or the ocean. Material could sediment. downstream temporary disposal be processed for commercial sale. site, or the ocean. No sediment modeling of this alternative. Fine sediment (<=1mm) would be slurry Fine material (accumulated) Coarse material (accumulated) Remove Sediment to dredged and piped to the ocean and coarse removed from the river system by removed from the river system Approx. 400 AF/yr less yield for Casitas MWD AP-Alt. Ocean by Slurry Pipeline material would be excavated and Appraisal Report hydraulic dredging and slurry using a conveyor belt and trucking with dam removal. High flow sediment 1BB and Conveyor/Trucking conveyor/trucked to the ocean (or other USBR 2000 pipeline. After drying, could be system to transport to ocean or bypass at Robles Diversion to flush chronic (Alt. 1BB) downstream disposal location). Dependent hauled to the ocean for beach downstream temporary disposal sediment. on water availability for slurry. replenishment. site. Accumulated reservoir area fines Accumulated coarse material Sediment deposition at Robles Diversion allowed to erode without other allowed to erode without other will increase. Sediment removal at diversion Dam would be removed in 9 separated stabilization during various stabilization during various may need to occur more frequently. AP-Alt. 2 Phased Natural Transport Appraisal Report phases (2-3 years btwn). Sediment would be phases. 6.0 MCY total sediment. phases. Sand: 54% of reservoir Turbidity a water quality problem in Casitas of Sediment (Alt. 2) USBR 2000 sluiced by natural creek flow. Silt/clay: 38% of reservoir sediment. Gravel/cobble: 8%. Reservoir; would need to restrict diversions sediment; assumed transport Total natural transport limited by during high turbidity periods. No mitigation £ 200,000 mg/l. sand transport using Yang (1973). provided. 32
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