Drainwise banner 02

Glossary of terms

DrainWise Project

Show Sidebar

Glossary of terms

A glossary of terms for stormwater and wastewater.


Is wastewater from toilets. It contains human waste.

Camera inspections

Closed circuit television inspections (CCTV) use a video camera to record the condition of a sewer pipe. The camera is remote controlled from the surface; video footage is reviewed to identify any defects such as cracks, root intrusions or leaky joints.

Dye testing

Dye testing may be conducted to confirm connections to the sewer. The test involves adding a special non-toxic dye to the sewer connection and monitoring a downstream sewer manhole for the dye.


Is the wastewater from the kitchen, bathroom sinks, bath, shower and laundry. It does not contain human waste. 

Gully trapGully trap.

Is the basin in the ground with a water seal to prevent foul odours of the sewer reaching the surface. Wastewater from your kitchen, bathroom and laundry is piped to a gully trap before emptying into the sewer. Gully traps are buried in the ground with the tops or surround raised above the ground to prevent surface water entering into the sewer.  See image.


Inflow is stormwater that enters directly into the sewer (wastewater) system. The cause is low gully traps, illegal downpipe connections to the sewer, cracked or damaged pipes.


Infiltration is stormwater that seeps into the ground and enters the sewer system through pipes and connections.  The cause is connection defects, cracks and joints in the pipes.


Used on stormwater and wastewater systems to allow access to the pipes for clearing of blockages or monitoring flow.

Property inspection

Inspection on residential and commercial properties in the Gisborne urban area by the DrainWise Team. Properties are inspected to investigate the risk of rainwater getting into the wastewater system.


Found under household fixtures such as basins and sinks, and also gully traps. Stops foul odours coming back into houses from the wastewater system.

Sewer system

Sewer pipes receive wastewater from within buildings - kitchen, bathroom, laundry, toilet. These pipes move wastewater to the treatment plant before its discharged through the marine outfall.

Smoke testing

Smoke testing is injecting smoke into a sewer manhole and noting where the smoke comes to the surface. The test is to identify direct stormwater connections to the sewer system, also known as cross-connections. The smoke is non-toxic, stainless, odourless and vegetable based.


Commonly known as guttering. Collects roof water and directs it to downpipes.

Storm trap

Can look very similar to gully traps, but are used to collect stormwater from the roof and section prior to discharge to the Council system via the property stormwater lateral.


Stormwater is rainwater that runs off surfaces such as your roof, the road, driveway, footpath, industrial yards and even the lawn. Stormwater pipes and drains collect the rainfall and carry it untreated to the nearest waterway. 
More information on stormwater

Stormwater lateral

Pipe that directs the property stormwater to the Council system. Often made of PVC or earthenware.

Stormwater sump

Chamber where stormwater is collected from surface runoff, such as in property back yards. The lid is usually grated to allow rainwater to enter.

Wastewater (commonly known as sewage)

Wastewater is used water and waste from our home's kitchen, laundry, bathroom and toilet; commercial properties and industries. 
More information on wastewater

Wastewater lateral

Pipe that directs the property wastewater to the wastewater mains in the street. Common pipe materials are PVC, earthenware, asbestos cement, reinforced concrete.


Managing our wastewater

Watch this video, it explains Gisborne's city's wastewater network