Foul and surface-water drainage basics

An introduction to the two kinds of drainage connection and the considerations that come with them.

Foul vs surface water

Foul water is wastewater from toilets, kitchens and washing. Surface water is rainwater run-off from roofs and hard surfaces. They are often handled by separate connections.

Connecting to the network

• New connections to the public sewer require an application and approval.
• Foul and surface water may connect to different parts of the network.
• The water and sewerage authority reviews and approves connections.

Build-over and diversions

Building over or close to a public sewer usually requires a build-over agreement. Where a sewer conflicts with your development, a diversion may be needed.

Adoption

New drainage infrastructure may go through an adoption process, where the authority takes on future ownership and maintenance. Requirements vary.