Project record

Honiara wastewater mains and two deep-sea outfalls

A large-diameter sewer pipe being lowered into a supported trench on the Fisheries-to-Ranadi section in Honiara in October 2024

Solomon Water

Honiara has rehabilitated two old wastewater outfalls and built part of the eastern sewer network, but the next marine package is not settled in public. The 2023 EIA designs two lines: 350 m by 400 mm at the National Referral Hospital and 500 m by 800 mm at Ranadi. Solomon Water's 2025 plan also repeats an older three-outfall basis with a 900-1,000 m by 357 mm NRH line and a 500 m by 312 mm Soap line, while separately budgeting NRH and Ranadi packages. ADB still lists bid documents in preparation and no new-outfall works award.

Project signal

Tender in Solomon Islands

Current status ADB still lists bid-document preparation for the new marine works; Solomon Water's public plan carries competing three-outfall, two-new-outfall and NRH/Ranadi package definitions, with no works award disclosed Source confidence Confirmed

Location

Solomon Islands / Global islands

Segment

Marine utilities

Status

ADB still lists bid-document preparation for the new marine works; Solomon Water's public plan carries competing three-outfall, two-new-outfall and NRH/Ranadi package definitions, with no works award disclosed / Confirmed

Last checked

19 July 2026

Coverage

Related sectors

Marine utilities is the primary work classification. Related sectors connect this record to adjacent marine delivery and market coverage.

Subject index

Related subjects

These subject pages bring together related projects, technical articles, reports, and evidence methods.

Project anatomy

Contract scope and delivery roles

Client / authority
Government of Solomon Islands; Solomon Islands Water Authority trading as Solomon Water
Delivery parties
Pacific Engineering Projects Ltd - contractor for the separate Ranadi Road-to-Goodwood sewer works; no contractor is disclosed for the NRH or Ranadi outfall works
Contract route
The wider Urban Water Supply and Sanitation Sector Project is supported by ADB, EU, World Bank, GEF and government financing. Solomon Water's 2025 corporate plan carried separate planning estimates of USD 13.2 million for the NRH sewer and outfall and USD 23.8 million for the Ranadi sewer and outfall, without naming contractors. ADB currently lists the outfall bidding documents in preparation. EIB approved a related facility in December 2025, but its environmental sheet says the new pumping stations and sea outfalls are not part of that facility.
Execution window
The February 2023 environmental assessment described a staged network and a two-year construction period for the outfalls and outfall pump stations. Solomon Water's 2025 corporate plan retained Q2 2027 as a planning completion date for the NRH and Ranadi packages. The current ADB status does not support treating that date as a contracted programme because bidding documents remain in preparation.
Works package
The 2023 EIA baseline covers approximately 15 km of pipes, six pumping stations, fine screening, a 350 m by 400 mm NRH marine outfall and a 500 m by 800 mm Ranadi marine outfall. Solomon Water's 2025 plan also reproduces an older basis with 13.4 km of gravity sewer, 4.1 km of pressure sewer and 'Outfalls (3)', then lists a 900-1,000 m by 357 mm NRH line and a 500 m by 312 mm Soap line. These are competing design histories, not a combined construction scope.
Marine interfaces
The later NRH and Ranadi concept crosses reclaimed foreshore, intertidal and subtidal ground before discharging beyond the nearshore zone. The EIA considers trenching, floating and controlled sinking of HDPE pipe, diffuser connection, backfill and rock or concrete-mat protection. The tender still needs to settle the number of new marine lines, final alignments, discharge points, lengths, diameters and seabed protection.
Commercial evidence boundary
The open demand includes final survey and UXO clearance, outfall pump stations, large-diameter HDPE supply and handling, beach and seabed trenching, controlled submergence, diffuser and protection works, environmental controls, testing and commissioning. The two public design histories are different enough to change pipe quantities, marine plant and installation duration. Neither proposed new outfall has a disclosed contractor or awarded price.

Project timeline

Material developments

Dated events that changed scope, counterparties, delivery, commissioning or operating status.

Open this project in the Change Log

ADB still lists the new outfall works at bid-document stage

The current record confirms two existing-outfall rehabilitations but does not disclose a construction award for the purpose-built NRH and Ranadi marine lines.

Source

EIB approved a related facility with the marine works excluded

The approval supports Honiara sewer reconfiguration, but the EIB environmental sheet limits its project to new sewer lines and a 60 cubic metre-per-day septage plant and says the new pump stations and sea outfalls are not included.

Source

The eastern landward sewer section reached 3.2 km

ADB's current implementation record reports 3.2 km constructed by 30 June 2025. That progress belongs to the landward network and does not establish marine outfall construction.

Source

Environmental design fixed a two-outfall baseline

The assessment defined a 350 m NRH line and 500 m Ranadi line, six pump stations and about 15 km of sewers, while leaving the final offshore installation method to procurement.

Source

Evidence gap

What remains unverified

Outstanding evidence

  • Issued works tenders that reconcile the two-outfall and three-outfall design histories
  • Final NRH and Ranadi lengths, diameters, discharge points and pump duties
  • Confirmed funding for the outfall pump stations and marine pipelines
  • Contractor award, notice to proceed and approved marine installation method
  • UXO clearance, bathymetry, geotechnical checks and final discharge coordinates
  • Construction of the 400 mm NRH and 800 mm Ranadi outfall lines
  • Diffuser, screening, standby-power and pump-station integration
  • Closure of obsolete nearshore outfalls and foreshore clean-up
  • Hydraulic testing, discharge permits, plume monitoring and operating acceptance

Related records 2

Reporting status

Tender, confirmed confidence

Last checked 19 July 2026 across 8 cited sources. The dated timeline above carries the project events.

Last checked 19 July 2026 Cited sources 8

Sources and related records

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Source collections

Project sources 8