WIVENHOE DAM RADIAL AND
BULKHEAD GATE PROTECTIVE COATING REFURBISHMENT
COMMITTED TO EXCELLENCE.
SECTOR / DISCIPLINE
Water Infrastructure
LOCATION
Wivenhoe Dam
Brisbane Valley Highway
Wivenhoe Pocket, Qld
DATE
JULY 2022
ASSET OWNER
Seqwater
CLIENT/DELIVERY AGENCY
GHD
VALUE
$7.5m
PROJECT DESCRIPTION
Seqwater is the Queensland Bulk Water Supply Authority and manages the SEQ Water Grid – an interconnected network of water catchments, storage dams, treatment plants, reservoirs and pipelines. Wivenhoe Dam is the largest dam in the water grid and is one of three Seqwater gated dams.
The Wivenhoe Dam Bulkhead Gate was built in 1984 and is used to isolate the dam water from the radial gates for maintenance purposes. The bulkhead gate was found to be not sufficiently sealing the water due to deteriorated seals and the annual patch painting is no longer achieving the protection to the gate structure.
The radial gates are manually operated structures that allow the
controlled release of water from the dam, typically during a flood event were showing signs of corrosion to metal work and degradation of the gate seals. Two of the five radial gates were previously painted in 2013 are to be repainted due to chalking.
JC CIVIL PROJECTS ROLE
JC Civil Projects was engaged by GHD to provide an independent cost estimate, program, risk and opportunity review of the Wivenhoe Dam Bulkhead and Radial Gate Protective Coating Refurbishment project. This service provided Seqwater with an out-turn cost estimate for use within the detailed business case phase.
KEY DELIVERABLES
JC Civil Projects played a pivotal role in several key aspects of estimating the project, including:
-
Prepared the project cost summary (total out-turn cost) in line
with first principles estimating, AACE, and industry best practice
principles, ensuring alignment with the Project Assessment
Framework (PAF) and the Building Queensland Business Case
Development Framework (BCDF) -
Developed a detailed delivery program and associated construction methodology
-
Conducted thorough risk analysis and opportunity reviews
Provided detailed constructability feedback to the client, fostering increased design collaboration with future tenderers -
Accurately forecasted time and cost for the project, facilitating the development of a detailed budget by the client
-
Developed a detailed construction methodology that allowed for complex scaffolding and reduced potential safety issues associated with cranage on the project.
KEY PROJECT HIGHLIGHTS
The project was part of the Sustaining Capital Planning
Investigations (SCPI) Contract, and split into two main areas of
works, including:
-
Area 1: Refurbishment of the bulkhead gate
-
Area 2: Refurbishment of the radial gates
Overall works delivered included:
-
Temporary works construction
-
Scaffold access
-
Temporary support for removal of gate seals
-
Removal of gate seal and clamp plate
-
Remove and service guide wheels and side rollers
-
Preparation (including abrasive blasting) and painting of the upstream radial gate structure
-
Prepare and paint the bulkhead gate structure
-
Preparation (including spot repairs) and painting of the downstream radial gate structure.
OUTCOMES AND ACHIEVEMENTS
JC Civil Projects produced a comprehensive project cost summary, delivery program, and methodology aligned with industry best practices and
provided detailed constructability feedback and optioneering
advice.