CACHE CREEK SETTLING BASIN SYMPOSIUM Managing the Settling Basin Who s Doing What! June 22, 2009 Francis E. Borcalli, P.E.
CACHE CREEK SETTLING BASIN SYMPOSIUM Managing the Settling Basin Who s Doing What! June 22, 2009 Francis E. Borcalli, P.E.
Arriving to one goal is the starting point of another. Where we started
YOLO COUNTY IRWMP WATER MANAGEMENT CATEGORIES: Water Supply and Drought Preparedness Water Quality Flood Management and Storm Drainage Riparian and Aquatic Ecosystem Enhancement Recreation
FLOOD ADVISORY COMMITTEE Assembled knowledgeable experts to assess situation Convened review and deliberation meetings Conclusions: No silver bullet! Lower Cache Creek & Cache Creek Settling Basin first
Well done is better than well said. What we have done
We started with Yolo County Flood Management Program now we are the
Organizational Structure Program Advisory Committee (PAC) YCFCWCD, City of Woodland, Yolo County YCFCWCD Administrative Lead Water and Aquatic Habitat Element Recreation and Riparian Habitat Element Cache Creek IP Flood Element YBIP PCIP SRWBIP Sloughs, Canals, and Creek IP Management Function Coordination Function CCIP Cache Creek Integrated Project PCIP Putah Creek Integrated Project SCCIP Sloughs, Canals, and Creeks Integrated Project SRWBIP Sacramento River West Bank YBIP Yolo Bypass Integrated Project Integrated Project
Mission: Minimize the risk from flooding in Yolo County while enhancing water supply, ecosystem functionality, recreation, and community values Program Elements: Public Outreach Flood Emergency Preparedness Watershed Assessment Flood Hazard Mitigation Projects Planning Projects Implementation and Maintenance Program Administration and Funding
SOLUTION PRINCIPLES Resilient to events greater than design Low maintenance Minimize structural features Enhance public and environmental values
Relationship with FloodSAFE California FloodSAFE California Supporting Projects Central Valley FED Central Valley Flood Protection Plan Urban Levees Program Channel Maintenance Improved Inspection Procedures floodsafe Yolo Pilot Program State Plan of Flood Control Others California Levee Database
FLOODED AREA - 1937 AND 1938
FLOOD OF FEBRUARY MARCH 1940
EXISTING 100-YEAR FLOODPLAIN (With Levee Overtopping)
Woodland & Yolo County need a no regrets solution to flood risks associated with Cache Creek and the Cache Creek Settling Basin!
CRITICAL FEATURE FOR FEASIBLE SOLUTION
EXISTING 100-YEAR FLOODPLAIN (With Levee Overtopping)
THE COMMUNITY S PERSPECTIVE 2003 feasibility study polarized the community it is now more unified Flooding from Cache Creek is documented it will occur again Woodland flooding is the product of less than adequate projects analysis I-5 and the CCSB
CACHE CREEK SETTLING BASIN Feature of the State Plan of Flood Control Dam No. 084 under jurisdiction of the Division of Safety of Dams Authorized and constructed for sediment management Levees being disaccredited by FEMA Outlet weir authorized to be raised 6-feet Deemed critical for Mercury management
CACHE CREEK SETTLING BASIN JUSTIFICATION Prevent sediment deposition of Woodland s abandoned waste water oxidation ponds. Avoid raising Bypass levees up to 2.2 feet from I- 5 to Fremont Weir. Avoid raising Ridge Cut levees 1.8 feet. Avoid raising Sacramento River levees up a maximum of 1 foot to the Sacramento Bypass. Decrease dredging Sacramento River and Bay by 88 acre-feet and 7 acre-feet, respectively.
CACHE CREEK LEVEES & SETTLING BASIN CHRONOLOGY OF MODIFICATIONS 1938 Construction of Initial Basin completed 1940 West levee moved West 400-feet 1943 C.C. Levees constructed from mouth of Basin to Yolo 1950 Basin modified for design flow of 24,000 cfs with Cobble Weir set at El. 28 (NAVD) 1961 C.C. Levees extended approx. 3 mi. upstream of Yolo & Basin modified for design flow of 30,000 cfs 1973 Cobble Weir raised 2 feet to El. 30 (NAVD) 1992 Basin levees raised to present height; West levee moved west 2,500 feet; and new outlet weir constructed for 30,000 cfs at El. 35 (NAVD) 2017 Outlet weir authorized to be raised to El. 41 (NAVD)
CHRONOLOGY OF CCSB WEIR MODIFICATIONS SETTLING BASIN YOLO BYPASS
WORK PLAN ACTIVITIES Topographic Data Acquisition City/County Drainage Manual Cache Creek Hydrology Update Institutional & Sustainable Funding Options Public Outreach Program Cache Creek / Cache Creek Settling Basin Flood Risk Reduction Alternatives Federal Appropriations FY10 USACE-CVFPB-Local Partnership
Progress always involves risk; you can t take second base and keep your foot on first. Where we are headed
Cache Creek Flood Risk Reduction Project Recovering flood conveyance through the CSBB is critical it can be implemented as a no-regrets project
CRITICAL FEATURE FOR FEASIBLE SOLUTION
CRITICAL ITEMS FOR PROJECT IMPLEMENTATION Executing feasibility cost sharing agreement with USACE and CVFPB Funding Federal, State, Local Conducting feasibility study October 1, 2009 target start date Collaborating with FloodSAFE California programs and projects Being a part of the CVFPP Responsible parties addressing long-term management of sediment and mercury while implementing a no-regrets flood solution
Questions?