A Street Permanent Embankment Stabilization Across from Crescent Ave in Castro Valley, Alameda County.
Summary
SCH Number
2024120461
Public Agency
Alameda County Public Works Agency
(ACPWA)
Document Title
A Street Permanent Embankment Stabilization Across from Crescent Ave in Castro Valley, Alameda County.
Document Type
NOE - Notice of Exemption
Received
Posted
12/12/2024
Document Description
The Alameda County Public Works Agency owns and maintains A Street Road in Castro Valley. Due to the 2022-2023 winter storm and high run off of flows, a retaining wall located on the eastbound side of A Street at the boundary between Unincorporated Castro Valley and adjacent to San Lorenzo creek failed. As a result, emergency temporary repairs were performed to fix the road in order to open the street for vehicle traffic and to prevent the road from continuing to erode and collapsing into the creek. The emergency repairs consisted of constructing a steel sheet pile retaining wall and placing approximately 630 cubic yards of rock slope protection and 860 cubic yards of 3/4 inch gravel along the creek bank below. Permanent repairs will stabilize the bank and address erosion issues by incorporating the existing rock slope protection into the new vegetated boulder revetment. The project will involve the removal of approximately 19 cubic yards of damaged concrete and the 630 cubic yards of rock slope protection and 860 cubic yards of 3/4 inch gravel that was placed during the emergency repair. The concrete will be removed to improve the environmental impacts of the site. A vegetated boulder revetment will be constructed along the creek bank. The revetment will be infilled with soil and vegetated with willow cuttings to enhance ecological restoration. A concrete waler and ground anchors will be installed to provide additional support to the existing sheet pile retaining wall, ensuring the bank's long-term integrity. Access to the creek will be provided via a temporary ramp built from a county-owned property, allowing safe transport of equipment. De-watering of the creek would be done by cofferdams and through a gravity or mechanical pump system. This ramp and cofferdams will be dismantled after project completion and restoration to previous conditions. After construction, the restored site will be monitored to assess vegetation growth and bank stability.
Contact Information
Name
Moses Tsang
Agency Name
Alameda County Flood Control & Water Conservation District
Job Title
Deputy Director
Contact Types
Lead/Public Agency
Address
Phone
Email
Name
James Yoo
Agency Name
Alameda County Public Works Agency
Job Title
Associate Environmental Compliance Specialist
Contact Types
Lead/Public Agency
Phone
Email
Location
Cities
Hayward
Counties
Alameda
Regions
Unincorporated
Cross Streets
A Street and Crescent Ave
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
Sec 15301, Existing Facilities
Reasons for Exemption
The proposed project constitutes repair, maintenance, and minor alterations to existing public facilities involving negligible expansion of use.
County Clerk
Alameda
Attachments
Notice of Exemption
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