Conceptual and Detail Design for the Manono Water Scheme
Samoa Water Authority
June 2011 – September 2011
GHD Ltd NZ
Preparation of Detailed Design for Improvement to the Manono Island Water System
Fully assess water needs of populations on Manono Island and the ability of existing systems to sustainably and reliably meet these needs. Confirm sustainable capacities of existing water sources and investigate all potential alternate sources. Alternate sources should include the possible option of establishing a desalinisation plant financed through JICA. Prepare a detailed long term water supply options study with costing and recommendations on preferred water supply systems. On adoption of the preferred option by the SWA, complete detailed designs, assist SWA to call tenders and advise on construction of works.
Analysis of Existing Water Supply Systems and Identification of options for Improvements
Gather all population information and assess water demand
Obtain information on sustainable yields from existing bores.
Analyse hydraulic capacity of existing networks including provision for leakage.
Test existing networks to confirm actual pressures and flows are within 5% of calculated values.
Provide a GAPS analysis of existing systems to identify upgrade requirements.
Analyse the environmental, technical and recurrent cost implications and benefits of a desalinisation plant for Manono.
Prepare Interim Report on Existing Water Supply System and options/ recommended outline solutions to strengthen the system. The objective will be to supply safe drinking water at a reasonable pressure with 24 hour supply.
Detailed Design of Works
Liaise with SWA, WSCU and MNRE to agree the preferred option and to finalise a scope for the detailed design.
Prepare a Preliminary Environmental Assessment Report (PEAR) for the preferred option and submit to PUMA. Liaise with PUMA to obtain approvals or to undertake further studies (e.g. EIS).
Undertake detailed design of all agreed works in the form of a Detailed Design Report including the required design drawings, technical specifications and Bill of Quantities.