Vineyard Pipeline Emergency Repair
Summary
SCH Number
2024111002
Public Agency
Zone 7 Water Agency
Document Title
Vineyard Pipeline Emergency Repair
Document Type
NOE - Notice of Exemption
Received
Posted
11/26/2024
Document Description
Zone 7’s field inspectors discovered that a segment of Zone 7’s Vineyard Pipeline where it crosses Arroyo Valle (at Bernal Avenue in Pleasanton; see map and photos below) has eroded by streamflow and has lost original structural support. This pipeline segment was constructed to be embedded below the channel bed and covered with a concrete cap. At present, this segment of pipeline cap is partially exposed under water within Arroyo Valle, with no soil cover above; the downstream side of the cap and pipeline have been eroded and exposed. The current condition of the pipeline is unstable and extremely vulnerable to winter streamflow forces as well as instream debris coming down from the upper reaches of the watershed (branches, trash, etc.). Action to stabilize and protect the pipeline is urgently required before creek flows increase, which would prevent later action to protect the pipeline, leaving it vulnerable to heavy winter storm flows.
The emergency repair is anticipated to include two repair steps over approximately 7 work days:
1) Minor repairs to access road / Staging. To accommodate the emergency repair, portions of the 500-ft. long maintenance access road require some limited improvements (e.g., filling gaps and potholes) to accommodate safe ingress and egress for equipment, which will be staged nearby, outside of the wetted channel.
2) Placement of rock to protect pipeline/cap. Within the work area, crews will clear the channel bed of organic debris and soft soil to promote a close contact of rock to underlying channel sediment. Rock will be placed upstream and downstream of the exposed pipeline cap and above the cap within the low flow channel for a total of approximately 80 linear feet. This includes 6” of drain rock overlain by 36” of 1/4 ton riprap.
No coffer dam or dewatering is proposed. Staging and general site preparations planned for November 26-27. In wetted channel work planned for December 2-6. Work is weather permitting; current forecast calls for no rain for this period.
Contact Information
Name
Elke Rank
Agency Name
Zone 7 Water Agency
Job Title
Senior Water Resources Planner
Contact Types
Lead/Public Agency / Parties Undertaking Project
Phone
Email
Location
Coordinates
Cities
Pleasanton
Counties
Alameda
Regions
Citywide
Cross Streets
Nevada St @ Bernal Ave.
Zip
94566
Total Acres
1.5
Jobs
1
Parcel #
various
State Highways
84
Railways
UPRR
Airports
Livermore Municipal
Schools
Thomas Hart, Amador, Harvest Park, Pleasanton Middle, Vintage Hi
Waterways
Arroyo Valle
Township
3S
Range
1E
Section
00
Base
MDBM
Other Location Info
Location is within the Arroyo Valle waterbody
Notice of Exemption
Exempt Status
Emergency Project
Type, Section or Code
15269(b)
Reasons for Exemption
The Vineyard Pipeline is a critical transmission pipeline essential to deliver treated water to the City of Pleasanton and other areas of Zone 7 Water Agency’s service area. The adverse consequences of pipeline failure here will be significant; in short, however, it would lead to direct impacts on important water delivery service. Furthermore, a rupture of this pipeline segment would result in high-volume releases of chlorinated water to Arroyo Valle.
County Clerk
Alameda
Attachments
Notice of Exemption
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