Natomas Levee Improvement Project - October 2020
NATOMAS LEVEE PROJECT
Natomas Levee Project—U.S. Army Corps of Engineers
Goal: Complete levee improvements started by SAFCA/State to provide Natomas Basin at least 200-year flood protection
Project Status: Project is fully authorized by Congress (2014 Water Resources and Reform Development Act). Appropriations are made on an annual basis
Cost Sharing Partners: SAFCA (local) and Central Valley Flood Protection Board (State)
Operation and Maintenance Responsibility: Reclamation District No. 1000
Construction Status: See Construction Phasing Map
October 2020 Status:
i. The Corps issued its 95% plans for this reach early in August and 100% plans are in progress. SAFCA is in the processing of acquiring necessary right of way including several homes.
ii. Clearing of trees and relocation of utilities starts in winter 2021 Contract Award is scheduled for September 2021 with cutoff wall and adjacent levee construction starting in spring 2022.
i. This construction project contract was awarded in spring, 2020. Initial clearing and stripping as well as demolition of three houses has commenced. Cutoff wall construction, construction of the adjacent levee and seepage berm will commence next spring. Don Caldwell has been representing the District and working with the Corps’ inspectors and resident engineers to provide project support.
ii. The plans have been completed for the Reach B, I 5 Window closure project. The bidding on this project is being held, waiting for the result of negotiations with Caltrans on a framework agreement with DWR, SAFCA, and the Corps covering their review and processing of comments on the various NLIP projects where Caltrans permits are required.
iii. Clearing and grubbing has commenced and full construction activity will commence in spring 2021. A separate project to close the I-5 window in Reach B at the crossing of the Sacramento River is scheduled for spring 2021.
i. The Reach C project was completed by SAFCA several years ago and the Districts’ role is now providing annual maintenance activities in this reach.
i. The relocation of the Vestal Drain was completed in early summer 2020, however the project is still in the final acceptance phase. District staff and consultants maintain constant contact with the Corps’ inspectors and Resident Engineers, lobbying for completion of the Districts’ punch list of deficiencies prior to flood season. The plans for reconstruction of Pumping Plant 4 have been repackaged into a separate project – having been deleted from the earlier construction project due to delays resulting from PG&E conflicts. Project construction award is scheduled for end of calendar year 2020. District consultants M & H and staff have conducted a review and have commented on these plans.
ii. Bids will be solicited soon for reconstructing Pumping Plant 4 including new plant pumps, motors and other equipment purchased during the NCC levee and canal work contract which concluded this summer. The schedule is to award the Plant 4 work by the end of 2020.
i. Reach E extends along the Pleasant Grove Creek Canal from Sankey Road north to Howsley Road.
ii. The Corps of Engineers completed the 65% plans in July. Comments were due by August 28. The District submitted comments along with SAFCA and State DWR. The proposed project includes limited areas of a 50-foot-deep cut off wall and levee widening with 3:1 back slope and a landside levee patrol road for the entire length.
iii. Comments were submitted on the 65% plans. Proposed work includes levee widening and limited cut-off wall. SAFCA and State DWR are working on right of way acquisition. The 90% plans are due in January 2021 with Contract Award scheduled for July 2021.
iv. As part of the project, the existing five drainage culverts through the levee foundation will be replaced with reinforced concrete pipe from beyond the waterside levee toe through the existing levee and the new widened levee section.
v. Current schedule is for contract award in July 2021 with construction complete by November 2022 (two construction seasons).
i. Reach F is along the Natomas East Main Drain Canal from Sankey Road to Elverta Road. It is being designed concurrently with Reach G
ii. The Corps of Engineers and non-federal sponsors (NFS) held the 10% design review in August. The Corps preliminary design does not include cut-off walls but does include levee widening—currently on both land and waterside. NFS are recommending no waterside fill and will have our geotechnical consultant review the design which may suggest some cutoff walls and consistent design with Reach G.
iii. The project team reviewed the preliminary design and provided input on the proposed design. Current plans propose levee widening and potentially limited cutoff walls. Current schedule is for 35% plans by January 2021 with Contract Award in spring 2022.
i. Reach G is along the Natomas East Main Drain Canal from Elverta Road to south of Elkhorn Blvd. It is being designed concurrently with Reach F.
ii. The Corps of Engineers and NFS held the 10% design review in August. The Corps preliminary design includes some limited cutoff walls and levee widening with landside slope flattening (3:1) and patrol road the entire length similar to Reach E.
iii. Next milestone is 35% plans in January 2021. Current schedule is for contract award in March 2022.
i. Levee cutoff walls, slope flattening and restoration of the levee section will be complete by November 1 of this year. Patrol / maintenance road grading may continue into 2021.
ii. Installation of raised discharge pipes for Pumping Plant 8 is scheduled for completion by November 1, 2020 but may need to be extended by a few weeks due to unforeseen difficulties with connections to the existing pipes.
i. Construction of the cutoff wall and levee slope flattening is essentially complete, requiring only repaving and stripping for contract completion.
ii. District staff, consultants, and project representative are winding down their project monitoring and support activities for this construction work.
iii. Construction of the cutoff wall is complete. A separate contract (Reach I Contract 2) to construct a patrol / maintenance road and perform levee slope flattening is scheduled to be awarded in late 2021 for construction in 2022 pending right of way acquisition