Date: March 16, 2021 To: Yuba Water Agency - Board of Directors From: Ryan McNally, Project Manager Subject: Staff Report – Interim Flood Control-Related Public Safety and Climatic Resiliency Plan
Recommendation
Receive an update from staff regarding an interim Flood Control-Related Public Safety and Climatic Resiliency Plan that focuses on the various flood risk reduction projects and studies Yuba Water Agency is presently engaged in throughout Yuba County.
Background
The Yuba Water Agency, consistent with the 2017 – 2021 Strategic Plan, is actively engaged in a number of projects to improve public safety and strengthen climatic resiliency by reducing the risk of catastrophic flooding in Yuba County.
Concurrent with the development of Yuba Water’s long-term public safety plan, staff has developed this interim Public Safety and Climatic Resiliency Plan to facilitate the Agency’s focus on specific projects and studies with measurable public safety and climatic resiliency results. Our goal is to support Yuba County in its efforts to achieve and maintain a 200-year level of flood protection for urban areas, and a 100-year level of flood protection for agricultural areas. This is consistent with prior Board of Director policies to continue to enhance flood protection and risk reduction efforts countywide.
The Plan is comprised of 12 projects that are intended to advance flood risk reduction and/or climatic resiliency in Yuba County. For FY 2020/21, the Agency has committed roughly $11.8 million toward flood risk reduction projects, with $6 million of that in grants to partnering reclamation districts, cities and Three River Levee Improvement Authority (TRLIA).
Our first step in this Plan is to assess the current flood risk reduction projects Yuba Water is engaged in at the study, design, planning or construction level. Staff will then later brief the Board of Directors on each of these individual studies and projects. Those briefings will include the status of each project, relative benefits, financing, and other considerations.
Discussion
The following are summaries of the various public safety and/or climatic resiliency projects Yuba Water is actively engaged in now:
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3/16/21 BOD Item 11 Attachment A Page 1 of 9 Marysville Ring Levee
The U.S. Army Corps of Engineers (USACE) is currently repairing sections of the 7.5-mile Marysville Ring Levee which surrounds the City of Marysville. With five (5) phases of the project complete since 2012, four (4) phases remain to be constructed. Final project closeout is expected in 2024. Once complete, this project is anticipated to provide the City with close to a 300-year level of protection. This is a federal flood risk reduction project, with the State of California and the Marysville Levee Commission as the non-federal sponsors. Yuba Water has played a significant role by providing technical, financial and policy support throughout this project’s development.
The project is advancing. Phase 2B is being re-bid for construction in 2021, and Phase 3 is underway, pending the completion of significant PG&E utility relocations. This necessary relocation effort, however, may result in increased project costs. The USACE Sacramento District is actively managing the issue and is in close coordination with staff. Total project costs include $115 million for design and construction and an additional $35 million in PG&E relocations and land acquisition. Agency staff expects to receive $6.5 million in grant funding for some of the relocation costs, in addition to the previous $2.5 million grant. A future briefing on the project will include more specific information on the project and its costs.
Project Cost(s): Marysville Levee District $ 1,000,000 State / Federal $ 111,500,000 Yuba Water Agency $ 2,500,000 Unsecured Need $ 35,000,000 ($6,500,000 grant request to Yuba Water expected) TOTAL $ 150,000,000
Yuba Goldfields Levee
To prevent potential breach flows from the Yuba River, the TRLIA completed Phase 1 of the Goldfields Levee in 2017 and achieved an interim 100-year flood protection level by constructing embankments designed to intercept potential breach flows from the Yuba River until Phase 2 is complete. TRLIA is now constructing Phase 2, which will achieve 200-year flood protection by way of a new levee that extends from the existing levee to high ground to control flows in the Goldfields. Funding for this project is anticipated to come from a Department of Water Resources (DWR) Urban Flood Risk Reduction grant, and other funding sources to be determined.
The project, once complete, will ensure flood flows do not sweep through the Goldfields into the south part of Yuba County. The Yuba Goldfields Levee project is expected to be complete this year.
Project Cost(s): TRLIA $ 11,700,000 State / Federal $ 42,600,000 Yuba Water Agency $ N/A TOTAL $ 54,000,000 Page 2 of 9
3/16/21 BOD Item 11 Attachment A Page 2 of 9
Reclamation District 10 Toe Access Corridor Project
Reclamation District (RD) 10 is constructing an elevated toe access corridor along the Feather River from the confluence of Simmerly Slough and the Feather River to around two (2) miles upstream on the east bank of the levee. Elevated toe access corridors provide all-weather access to landside levee toes in areas where ponding water and/or seepage may preclude access for flood monitoring or emergency flood fighting activities. The project also includes the extension of drainage culverts and a safety fence along the landside toe of the new access corridor. Yuba Water is supporting RD 10 by providing $1.3 million to fund the design, permitting and construction of this project.
Total project costs were originally expected to be $1.3 million. While design, permitting and acquisition costs are within budget, an updated construction estimate exceeds the original $700,000 estimate by $255,000. As a result, staff expects to receive a supplemental funding request once the final bids are received this summer. Construction is scheduled to begin summer 2021 and be complete prior to the upcoming flood season. Additional reaches of toe access corridors in RD 10 may be pursued in the future.
Project Cost(s): RD 10 $ N/A State / Federal $ N/A Yuba Water Agency $ 1,300,000 Unsecured Need $ 255,000 TOTAL $ 1,555,000
Bear River Setback Levee
RD 817 plans to construct a 2,800-foot-long setback levee along the north bank of the Bear River west of Wheatland to repair a critical erosion site. This project was awarded a DWR Flood System Repair Program (FSRP) grant with a 90% state cost share. Total project costs are estimated at approximately $11 million.
A robust design process identified several cost savings elements to reduce the cost by $1.58 million and the resulting cost savings has enabled the team to coordinate with DWR to repair 12 pipe crossings in RD 817. The pipe crossings needed repair, or replacement, due to corrosion, failures or inadequate size, or for removal due to altered land uses that no longer require these drainage features. These pipe crossings were identified by the Utility Crossing Inventory Program as the responsibility of RD 817, and DWR funded an evaluation of all District pipes through the Deferred Maintenance Program (DMP). Although these were not originally part of the Setback Levee project, these deficiencies were identified as critical repairs, and DWR requested they be repaired utilizing the excess Setback Levee grant funding. Construction may begin as early as this summer and be complete by 2022.
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3/16/21 BOD Item 11 Attachment A Page 3 of 9
Project Cost(s): RD 817 $ N/A State / Federal $ 9,900,000 Yuba Water Agency $ 1,100,000 (+$1,000,000 temporary cash flow loan) TOTAL $ 11,000,000
Hallwood Side Channel Project
This Hallwood Side Channel Project will remove up to 3.2 million cubic yards of sediment from the Yuba River below Daguerre Point, and enhance up to 157 acres of seasonally inundated habitat to restore the natural river and floodplain processes, including the removal of the Middle Training Wall and improvement of nearly eight (8) miles of side channels. The project will benefit the community of Hallwood, the City of Marysville, and RD 10.
An extraordinary benefit to this project is that Teichert is providing a substantial in-kind contribution through $72 million worth of grading and extraction of aggregate material utilizing the conveyor system in conjunction with the North Training Wall project.
Phase 1, completed in 2020, removed 1.2 million cubic yards of sediment and restored 89 acres of floodplain and habitat. Phase 2 is expected to begin this year and will continue the removal of approximately 800,000 cubic yards of the Middle Training Wall and sediment, restoring 34 more acres of floodplain and habitat. Phases 3 and 4 will eventually remove an additional 815,000 and 400,000 cubic yards of material and restore an additional 13 and 21 acres of floodplain and habitat, returning nearly 2.5 miles of the Yuba River to its natural state. The project is scheduled for completion over the next 5 years in conjunction with the North Training Wall Project– provided funds are available.
Project Cost(s): Yuba Water Agency $ 3,200,000 Teichert $ 72,000,000 State / Federal $ 6,700,000 (planning and design) Unsecured Need $ 2,000,000 (grant application submitted) TOTAL $ 83,900,000
Yuba River North Training Wall Project
This project is being implemented by TRLIA through Yuba Water Agency grants to reshape the existing North Training Wall and extend it upstream to connect to the high ground near the Cordua Canal fish screen. When complete, the project will improve flood protection to the community of Hallwood from high flows on the Yuba River, as well as providing added flood protection to Marysville and RD-10. To minimize costs, construction is proposed to be completed using a conveyor system in close coordination with Phase 2 of the Hallwood Side Channel Project.
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3/16/21 BOD Item 11 Attachment A Page 4 of 9
Yuba Water has previously funded $1 million for the project design and interim repairs. Construction on the final repairs is anticipated to begin this Spring. Total remaining Phase 1 costs are estimated at $1.5 million, of which Teichert has agreed to contribute $500,000, and the remaining $1 million is being sought from Yuba Water by TRLIA. Phase 2 is estimated to cost $6.8 million and is contingent on additional grant funding. TRLIA continues to seek additional funds from the Federal Emergency Management Agency (FEMA) and DWR to leverage Yuba Water funds, with the goal of completing Phase 2 in the next 10 years.
Project Cost(s): Yuba Water Agency $ 2,000,000* Teichert $ 500,000 State / Federal $ Grant TBD Unsecured Need $ 6,800,000 TOTAL $ 8,700,000
*TRLIA is currently seeking $1,000,000 in addition to the original $1,000,000 from Yuba Water for the construction of Phase 1.
Bear River Corridor Management Plan
The Bear River Corridor Management Plan (CMP) is a local and State partnership to develop a plan that will be utilized to obtain permits and coverage for operation, maintenance, repair, replacement, and rehabilitation of the Bear River levees and channels, which provide flood protection for Wheatland and RD 784, as well as portions of Sutter and Placer Counties south of the Bear River.
The Agency has funded the project team, including MBK Engineers and Jacobs Engineering, in cooperation with several Reclamation Districts and TRLIA, to develop the initial draft Plan. Remaining work toward the final product will be funded by DWR through the Feather River Regional Flood Management Plan and is expected to be completed later this year.
Project Cost(s): Yuba Water Agency $ 135,000 DWR $ 200,000 TOTAL $ 335,000
Wheatland FEMA Leveed Area Mapping Procedures Analysis
The project team is currently working with FEMA to analyze the Wheatland area and determine if the designated floodplain area could be reduced for the existing residents. As background, in previous FEMA mapping efforts throughout Yuba County, areas that were protected by unaccredited levees were mapped as if the levees did not exist, resulting in pushback from numerous communities. As a result, FEMA developed the Leveed Area Mapping Procedures Analysis to address areas with unaccredited levees or areas with partially accredited levees that allow local communities to evaluate various breach or overtop scenarios to determine the FEMA regulated floodplain.
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3/16/21 BOD Item 11 Attachment A Page 5 of 9
Preliminary analysis shows only minor changes to the floodplain using the revised procedures, so the project is on hold pending further discussion with Yuba County and the City of Wheatland to determine whether to continue with the FEMA remapping process.
Project Cost(s): Yuba Water Agency $ 150,000 TOTAL $ 150,000
Secondary Spillway Project
The Secondary Spillway project will enable Yuba Water to pre-release stored water, as well as excessive inflow into New Bullards Bar Reservoir into the Lower Yuba River in advance of and during, severe storm events. The project will also allow the Agency to create additional storage to capture peak flood flows and reduce peak flood releases. The Secondary Spillway consists of two gates set at an invert elevation of 1,893 feet and has a release capacity of 35,000 cfs. The $225 million project will utilize an open channel to release water from New Bullards Bar Dam and with 30% design complete, staff expects 60% design available for review later this year.
The operation of the spillway was simulated as part of multiple feasibility studies utilizing Forecast Informed Reservoir Operations (FIRO) operations and found to be extremely effective at reducing downstream peak flows in the region. The Secondary Spillway has also been tentatively integrated into the Yuba-Feather FIRO and Lake Oroville and New Bullards Bar Water Control Manual update projects.
Project Cost(s): Yuba Water Agency $ $11,040,000 State / Federal $ TBD – A funding plan is being developed TOTAL $ $225,000,000
Forecast Informed Reservoir Operations
Yuba Water is working closely with DWR and the Scripps Institution of Oceanography (Scripps) on a Forecast Informed Reservoir Operations (FIRO) initiative for the Yuba and Feather Rivers. FIRO is a promising forecasting tool which employs advanced technologies to allow agencies like Yuba Water to better predict, and manage, weather forecasts and reservoir operations. Yuba Water collaboration with DWR and Scripps, on the Yuba-Feather FIRO project, is designed to improve Atmospheric River and reservoir run off forecasting in the Yuba and Feather river watersheds.
This initiative will complement the Agency’s operations of dams and reservoirs in the Yuba River, and thereby enhance public safety, water management, and climatic resiliency. This program will also support the USACE in its process to update the Water Control Manual for New Bullards Bar Dam. The mechanism for applying the new forecasts and enhanced project operations is through the existing Forecast Coordinated Operations framework. This work is expected be fully integrated into the New Bullards Bar Water Control Manual update process in 2024 Page 6 of 9
3/16/21 BOD Item 11 Attachment A Page 6 of 9
Project Cost(s): Yuba Water Agency $ 2,500,000 State / Federal $ 2,900,000 TOTAL $ 5,400,000
New Bullards Bar Water Control Manual Update
The New Bullards Bar Water Control Manual (WCM) is foundational to flood protection in Yuba County and the function of the New Bullards Bar Dam because it serves as the operating rules for the flood control element of the facility.
This USACE update to the WCM is critical because the current flood operating rules are primarily based on the time of year, and generally do not include provisions to use specific forecasts to inform or trigger releases. When complete, however, this more advanced USACE approved operating procedure will benefit the people of Yuba County by being far more adaptive and take advantage of improving forecasts realized by through the FIRO project. Since last year, Yuba Water has been working closely with consultants, partners and members of the USACE WCM development team to assist in the update of this manual. A new manual is scheduled to be available in 2024.
Project Cost(s): Yuba Water Agency $ 500,000 State / Federal $ 2,000,000 TOTAL $ 2,500,000
Forecast Coordinated Operations
Forecast Coordinated Operations (F-CO) is a multi-agency program to coordinate flood operations of the New Bullards Bar Dam with Oroville Dam to minimize downstream flood emergency impacts. This is achieved through a common decision support system and improved communication between Yuba Water, DWR, USACE, and the National Weather Service.
This successful program has enabled local and state project operators to meet downstream flow objectives and minimize the risk of flooding. Continuing improvements in flood data collection and modeling tools, risk evaluation tools, real-time information, and flood forecasts are being implemented by the agencies under F-CO. This is an ongoing project, which started in 2005, and is the foundation of the more advanced and complementary programs including FIRO and the Secondary Spillway projects.
Project Cost(s): Yuba Water Agency $ 175,000 (to date) State / Federal $ 4,900,000 TOTAL* $ 5,075,000 (to date)
*This is an ongoing program and future costs are expected to be around $100,000 annually. Page 7 of 9
3/16/21 BOD Item 11 Attachment A Page 7 of 9
Yuba County Real-Time Inundation Mapping Tool
The project will implement a ‘Real-time Inundation Mapping’ (RTIM) tool that combines forecasts of flows in the Feather and Yuba River with potential levee failure information to produce and disseminate maps of expected inundation to the Yuba County Office of Emergency Services (OES) and Sheriff’s Offices (YCSO).
The RTIM will be operated by Yuba County and include inundation mapping models and interactive dashboards to aid in emergency management, emergency planning, and training. The project will adapt existing hydraulic models for real-time inundation mapping purposes, will integrate components of the F-CO tool with these models and deploy the resulting application on Yuba County infrastructure and in the cloud.
Implementation of the finished product will provide the county with an opportunity to have a state- of-the-art tool at its hands and further lead the way in Emergency Management and Disaster Response thereby creating a safer community for the residents of Yuba County.
Project Cost(s): Yuba Water Agency $ 440,000 State / Federal $ N/A TOTAL $ 440,000*
*Grant request of $40,000 for the feasibility study was approved in 2020, a grant request for the remainder will be presented to the Board this Spring.
Flood Risk Management Plan
There are no shortage of public safety and climatic resiliency needs in Yuba County. The Agency is strengthening its commitment to identify and address these needs, and to evaluate potential cost- sharing opportunities.
To help provide direction, the Agency has retained HDR to develop a comprehensive flood risk management plan to identify short term projects that meet high-priority needs, as well as long term programmatic planning to provide sustainable flood protection under changing conditions. A primary focus of the plan is to ensure the Agency is well positioned for state or federal funding opportunities as we embark on these critical public safety and climatic resiliency infrastructure improvements. Staff expects this plan to be complete in early 2022.
Project Cost(s): Yuba Water Agency $ 400,000 State / Federal $ N/A TOTAL $ 400,000
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3/16/21 BOD Item 11 Attachment A Page 8 of 9
Yuba County Real-Time Inundation Mapping Tool
The project will implement a ‘Real-time Inundation Mapping’ (RTIM) tool that combines forecasts of flows in the Feather and Yuba River with potential levee failure information to produce and disseminate maps of expected inundation to the Yuba County Office of Emergency Services (OES) and Sheriff’s Offices (YCSO).
The RTIM will be operated by Yuba County and include inundation mapping models and interactive dashboards to aid in emergency management, emergency planning, and training. The project will adapt existing hydraulic models for real-time inundation mapping purposes, will integrate components of the F-CO tool with these models and deploy the resulting application on Yuba County infrastructure and in the cloud.
Implementation of the finished product will provide the county with an opportunity to have a state- of-the-art tool at its hands and further lead the way in Emergency Management and Disaster Response thereby creating a safer community for the residents of Yuba County.
Project Cost(s): Yuba Water Agency $ 440,000 State / Federal $ N/A TOTAL $ 440,000* *Grant request of $40,000 for the feasibility study was approved in 2020, a grant request for the remainder will be presented to the Board this Spring.
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3/16/21 BOD Item 11 Attachment A Page 9 of 9