HomeMy WebLinkAbout04.a Update on Grayson/Walnut Creek Levee Improvements, DP 7341Page 1 of 4
Item 4.a.
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December 4, 2024
TO: ENGINEERING AND OPERATIONS COMMITTEE
FROM: AMANDA CAUBLE, ASSOCIATE ENGINEER
DAN FROST, SENIOR ENGINEER
REVIEWED BY: DANEA GEMMELL, PLANNING AND DEVELOPMENT SERVICES DIVISION
MANAGER
GREG NORBY, DEPUTY GM - OPERATIONS & ENGINEERING
ROGER S. BAILEY, GENERAL MANAGER
SUBJECT: RECEIVE UPDATE ON GRAYSON/WALNUT CREEK LEVEE
IMPROVEMENTS (DP7341)
Please see the attached update and overview for the Grayson Creek/Walnut Creek Levee Improvement
Project. This is a companion item to the California Environmental Quality Act consideration for
the relocation of Contra Costa Water District's Alum Residual Pipeline Project located on Central San's
treatment plant, which is also on the Engineering & Operations Committee agenda for December 4, 2024.
Staff will present the material during the meeting and answer any questions.
Strategic Plan Tie -In
GOAL ONE: Customer and Community
Strategy 3 - Build neighborhood and industry relations
GOAL SIX: Infrastructure Reliability
Strategy 1 - Manage assets optimally
ATTACHMENTS:
1. Presentation
December 4, 2024 EOPS Regular Committee Meeting Agenda Packet - Page 28 of 35
Page 2 of 4
December 4, 2024
Grayson/Walnut
Creek Levee
Improvements
Update
Engineering and Operations
Committee
Danea Gemmel[
Planning and Development Services Division Manager
Dan Frost
Senior Engineer
Amanda Cauble
Associate Engineer
Highlights of Levee Project
PROJECT ELEMENTS
Raise Walnut and Grayson Creek levees along the
wastewater treatment plant to provide protection
against a 0.2% ("500-year") storm event with three feet
of freeboard
Raise approximately 7,400 linear feet of levee from
Highway 4 to BNSF railroad by 2.5 to 3 feet
Selected to receive a Building Resilient Infrastructure and
Communities (BRIC) Grant
Property transfers with Contra Costa County
New high security fencing along eastern property South
of Imhoff Drive
Relocation of lighting, cathodic protection, and
protection of electrical and instrumentation vaults
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BENEFITS
Levee will protect $150M+ of existing
treatment plant assets
Increased protection from:
Catastrophic failures (flooding tunnels and basements,
influent, solids handling, primary effluent and final
effluent pumps)
Loss of service
Emergency discharge and/or backup of untreated
wastewater into streets and Martinez, Concord, and
Pleasant Hill neighborhoods
E
December 4, 2024 EOPS Regular Committee Meeting Agenda Packet - Page 29 of 35
Page 3 of 4
Project Partners =�
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US Army Corps
of Engineers.
CONTRA COSTAE
PUBLIC WORKS
Flood Control
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Cal OES
Water Boards
�� San Francisco Bay
Conservation and Development ►�
Commission
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PnoJect Design and Constnuiction JPurpow; County Public WoTks leadin
tronmental review, p—iLLin&
d—Sa and construction
with Central San review)
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December 4, 2024 EOPS Regular Committee Meeting Agenda Packet -Page 30 of 35
Page 4 of 4
Future Board Actions
E&O Dec 2024 Levee Project/CCWD Alum Pipe Relocation:
Find the Project Exempt from CEQP 11riv, ; W
REEP Jan 2025 — CCWD Alum Pond Lease:
Set and Conduct a Public Hearing to Declare Alum Ponds a
Unneeded and Authorize a Lease Agreement with CCWD with —
a Maximum Ten -Year Term
E&O Jan 2025 — Levee Project MOU:
Authorize the General Manager to Amend the Agreement
with CCC Flood Control District for Implementing the
Grayson/Walnut Creek Levee Improvement Project
E&O TBD — Future Item — Levee Project Grant:
Adopt Resolution Accepting Terms for a Building Resilient
Infrastructure and Communities (BRIC) Grant for the
Grayson/Walnut Creek Levee Improvement Project, s
December 4, 2024 EOPS Regular Committee Meeting Agenda Packet - Page 31 of 35