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Knightsen Wetland Restoration Project
Project Overview
Overview
East Contra Costa County Habitat Conservancy and partners are developing a habitat restoration project on a 645-acre property east of the Knightsen community. The project team is currently developing concept plans, considering multiple objectives that will create and restore wetlands and other habitat, provide community flood protection, improve Delta water quality, and explore recreation opportunities.
Project Brochure (PDF)
Location
Knightsen is located in the Sacramento-San Joaquin Delta on a generally flat plain along the old Delta shoreline. Historically, the area drained as sheet flow and some shallow channels toward wetlands that lined the water’s edge of the Delta. The flat topography of the area, combined with a variety of constructed features such as railroad tracks, roads, and levees that prevent water from reaching a natural outlet, results in flooding.
Background
A history of flooding and poor stormwater quality prompted the Contra Costa County Public Works Department, in conjunction with the Knightsen Town Advisory Council, to conduct a feasibility study to determine the best approach to address drainage concerns in this region. This study, as well as other studies undertaken since then, identified the 645-acre project site as a good location to direct and store floodwaters, thereby reducing flood impacts in the community. Acquisition of the property and development of the multi-objective restoration project would therefore benefit the community when future drainage improvements are built.
The East Contra Costa County Habitat Conservancy is leading the effort to develop the project, recently producing conceptual design alternatives for public comment. This conceptual alternative development phase of work is expected to be complete by October 2019. In the next project phase, project alternatives will be analyzed, refined, and a preferred design will be selected.
Project Partners
- East Contra Costa County Habitat Conservancy
- Contra Costa County Public Works Department - Flood Control District
- East Bay Regional Park District
Updates
In addition to regular agricultural activities on the property, other activities will be occurring intermittently. The following activities are scheduled.
Week of September 7, 2020
Activity: Geotechnical Field Investigations
Soil test pits are planned in areas of the property north of Delta Road to evaluate the type of soil materials.
Reason: Geotechnical engineers and hydrologists will be on the property performing field investigations to evaluate existing conditions that will inform the design of the levees to protect adjacent properties, understand potential onsite restored habitats and to support continued groundwater investigation.
Week of June 15, 2020
Activity: Geotechnical Field Investigations
Soil test pits are planned in internal areas of the property to evaluate the type of soil materials and located areas with soils suitable for use as levee fill.
Reason: Geotechnical engineers will be on the southern and eastern parts of the property performing field investigations to evaluate existing conditions that will inform the design of levees to protect adjacent properties, and to support continued groundwater investigation. Soil analyses will include slope stability including static and seismic loading, settlement and seepage evaluations.
Week of June 8, 2020
Activity: Geotechnical Field Investigations
Soil test pits are planned in internal areas of the property to evaluate the type of soil materials and located areas with soils suitable for use as levee fill.
Reason: Geotechnical engineers will be on the southern and eastern parts of the property performing field investigations to evaluate existing conditions that will inform the design of levees to protect adjacent properties, and to support continued groundwater investigation. Soil analyses will include slope stability including static and seismic loading, settlement and seepage evaluations.
Week of June 1, 2020
Activity: Geotechnical Field Investigations
Cone Penetration Tests (CPTs) are planned to measure soil structural qualities to explore potential project levee alignments.
Week of May 18, 2020
Activity: Geotechnical Field Investigations
Exploratory borings will be drilled to retrieve soil samples to test areas of the site perimeter along potential project levee alignments; and ground monitoring wells will be installed to support continuing groundwater investigation
Week of December 9, 2019
Activity: Road Improvements
Reason: To ensure that there is safe access to the agricultural pumps year round, the road that parallels Eagle Lane and No Name Slough will be improved to be an all-weather access road. These improvements will allow staff and contractors be safely access the pump station and remove water off the site during wet weather.
Week of December 1, 2019
Activity: Road Improvements
Reason: To ensure that there is safe access to the agricultural pumps year round, the road that parallels Eagle Lane and No Name Slough will be improved to be an all-weather access road. These improvements will allow staff and contractors be safely access the pump station and remove water off the site during wet weather.
Note: Delayed due to rain.
Activity: Geotechnical Field Investigations
These initial investigations will consist of cone penetration tests and drill borings along potential levee alignments.
Reason: Geotechnical engineers will be on the southern and eastern parts of the property performing field investigations to evaluate existing conditions that will inform the design of levees to protect adjacent properties. Initial analyses will include slope stability including static and seismic loading, settlement and seepage evaluations.
Public Meeting 2
Thursday, July 11, 2019
7 pm - 8:30 pm
Knightsen Farm Bureau
3020 2nd Street, Knightsen
Meeting Announcement (PDF)
Meeting Materials and Notes (PDF - 4.7 MB)
Public Meeting 1
Wednesday, May 2, 2018
7 pm - 8:30 pm
Knightsen Farm Bureau
3020 2nd Street, Knightsen
Studies, Assessments, and Resources
Online Resources
Technical Studies 2019 - 2021
- Assessments and Studies Plan (PDF)
- Baseline Soils Evaluation and Hydrologic Study (PDF - Large Document 9 MB)
- Biological Resource Assessment and Botanical Resource Survey Report (PDF - Large Document 14 MB)
- Utilities Constraint Memo (PDF)
- Weed Assessment (PDF)
- Wetland Delineation (PDF - Large Document 28 MB)
- Surface Water Hydrology Assessment - UPDATED (PDF)
- Conceptual Alternatives Report - UPDATED (PDF - Large Document 20.4 MB)
- North Parcel Soil Trenching Memo - February 2021(PDF)
- Geotechnical Data Report - August 2020 (PDF)
Background Documents
Funding for the various stages of this effort including acquisition, studies, assessments and design has been provided by: California Coastal Conservancy, California Department of Fish and Wildlife, California Wildlife Conservation Board, Contra Costa County Flood Control & Water Conservation District, East Bay Regional Park District, East Contra Costa County Habitat Conservancy, Knightsen Community Services District, Sacramento - San Joaquin Delta Conservancy, and U.S. Fish and Wildlife Service.