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: Page 1 of 9 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. Page 3 of 9 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.