Case Study: Kawakawa Bay – Vacuum Sewer System Transformation

Project Overview

Client: Manukau Water Ltd (now part of Watercare Services Ltd)

Location: Kawakawa Bay, New Zealand

Challenge: Replace an aging septic system with a cost-effective, environmentally safe, and reliable sewerage network for a seaside township.

Key Outcomes:

  • Beach declared safe for swimming within 12 months.
  • Significant reduction in untreated sewage discharge.
  • Award-winning environmental and sustainable design.
Kawakawa Bay NZ

The Challenge

Kawakawa Bay is a picturesque coastal town with:

  • A resident population of ~700 (increasing to 2,000 during holidays).
  • High water tables, poor drainage, and flat topography.

The existing septic systems caused severe environmental concerns:

  • Untreated sewage discharged onto the beach.
  • Public health warnings on seafood consumption and recreational water use.

Manukau Water needed a solution to:

  • Overcome challenging terrains.
  • Minimize power requirements and operational complexity.
  • Ensure resilience during seasonal population surges.

Our Solution

Innovative Vacuum Sewerage System:

  1. Minimal excavation required, reducing disruption.
  2. Negative pressure operation ensures zero leakage or overflow.
  3. Ability to handle seasonal flows
  4. Public ownership eliminates dependence on private systems.
  5. Low cost maintenance with back up power
  6. Telemetry-enabled monitoring enhances operational control.

Implementation

Key Features:

  • Shallow trenches for reduced installation costs.
  • Low-power vacuum pump station with solar backup.
  • Real-time system monitoring for efficient maintenance.

Community Impact:

  • Fast and efficient construction minimized resident inconvenience.
  • Immediate improvement in marine water quality.

Results

  1. Environmental Impact: Marine water quality drastically improved.
    • Beach reopened for swimming.
    • Warning signs removed within a year.
  2. Cost Efficiency: Lower capital expenditure compared to alternative systems.
  3. Sustainability Recognition:
    • Awarded the Arthur Mead Environment and Sustainability Award.

In 2010, following extensive research, which included visits to Flovac systems in Queensland and New South Wales, Manukau Water commissioned the first vacuum sewerage system in New Zealand.

“Our research concluded that vacuum had all the advantages of being a clean solution that required minimal excavation,” says Porter. “After talking to operators in Australia, we also decided that a publicly-owned system was going to be desirable over a privately-owned system.

There was nervousness because this was first time a vacuum system was being used in  New Zealand, and there was no local knowledge, but from an operational point of view it’s been a great experience.”

“One of the things that particularly impressed us was the simplicity of the connection to the vacuum pits and the fact that it was completely under our control, avoiding the need for individual home-owners to operate privately-owned systems. More recently the system has incorporated telemetry for monitoring, further enhancing our operational control.”

Vacuum has proved over a long period that it’s a good engineering option, and that’s why it is now being expanded to new residential developments in the Auckland region.”

Why Choose Flovac?

Our vacuum sewerage systems are designed for environmentally sensitive regions and challenging terrains, offering:

Low environmental impact.

High reliability and ease of maintenance

Contact Us

For more information, visit flovac.com or email [email protected].