The Rewa Water Supply Feasibility and Investigation Study (including Survey and Geo-technical services ) for a 40 Million Litre per Day(MLD) Water Treatment Plant, a 80 MLD Intake Pumping Station, 10ML Reservoir and 26 kilometres (km) pipeline.
The Rewa River Water Supply Scheme which was completed in December 2015, involved the design and construction of a new water supply source and water treatment plant for the Suva-Nausori Water Supply System. The key components of this project included a new river intake and pumping station on the Rewa River, new clear water reservoir and pumping station, 26kms of pipeline to connect to existing water supply system servicing Nausori and surrounding areas.
This project was the first major project undertaken for the Water Authority of Fiji (WAF) using funding obtained from the Asian Development Bank (ADB)
It was recognised that an interdisciplinary team drawn from a number of MWH offices would be required to deliver this project successfully within the required timeframe and budget. The nominated Project Director engaged with some of the key staff during the proposal phase to identify the required resources and opportunities to use collaborative working tools to limit requirements for travel to Fiji and the associated costs and to identify ways in which a cost effective feasibility report and preliminary design could be delivered. The approach identified and subsequently followed during the delivery of the work included:
Bringing in technical specialists at the outset to resolve key design criteria and issues quickly with WAF
Adopting a project delivery model that used a series of technical notes to agree the various issues and basis of design with WAF for all the key aspects of the work including the raw and treated water quality parameters, water treatment process selection, pipeline materials and alignments, reservoir configuration and capacity, project staging, control system integration etc.
Use of the MWH process design tools and spreadsheets to develop the WTP design and sizing of the process units
Use of the existing preliminary design developed for the Bukit Barun Stage 8 WTP project in Brunei that had the same water treatment process that was being considered for Rewa and was sufficiently developed such that design outputs could be readily reused. The use of the existing 3D design models (which were quickly resized to suit the new plant configuration and dimensions) provided a significant increase in efficiency
The use of RNet staff who had recently worked on the Bukit Barun Stage 8 WTP project and were completely familiar with the design and able to make rapid changes to the original documentation to suit the requirements for the Rewa WTP
Use of a recent WTP filtration tank block configuration from work being undertaken in UK by RNet
Use of previous assessments of sludge dewatering technologies undertaken by MWH in the USA and modified for Brunei to enable WAF to come to a quick resolution on the sludge treatment process
The use of collaborative tools to keep the client up to date. This included having the Client attend fortnightly progress meetings at the MWH offices so that technical specialists could join using Skype and use screen sharing to present their reports
Delivery of the WTP preliminary design using 3D CAD which enabled the design to be quickly varied to optimise the site layout with respect to foundations, site access, pipework layouts, excavations and earthworks cut/fill balances
Investigate and confirm suitability of proposed sites for key components
Topography Survey for proposed site and pipeline route
Identify options for configuration/staging of works
Determine water treatment objectives, assess treatment process options and identify preferred option
Develop preliminary designs and cost estimates for proposed option
Review construction requirements and related issues
Overall feasibility of the proposed Rewa Water Supply Scheme.
2016 MWH Global Beacon Award Winner – Global internal award that recognizes teams that demonstrate excellence in knowledge transfer and reuse