What do we mean by “rezoning”?
When we get reports of customers with no water our first thought is “how do we get the water back on” rather than how do we fix the burst main. When there has been a burst main that is causing people to be without water the majority of the time we get the water back on in less than an hour. Often the water comes back on by “rezoning” rather than fixing the main straight away. But we appreciate this is not always the case.
So what does it mean?
Simple speaking it means we supply your water through different water mains, which means the water at your home starts to flow again. Our network is split into a number of different zones, called Waste Water Districts. Most of these zones can be supplied through more than one route. Valves across the network allow us to change the route, so by turning the valve we can bring water into the zone from different routes as well as stopping it coming from other routes.
When we get reports of a burst main we first send a District inspector out to investigate. Whilst this is happening we will look at possible rezoning options. If there is a rezoning option the District Inspector can implement this once they have completed a risk assessment on site. This is how we manage to get the majority of people back in water in under an hour.
Rezoning can sometimes see a drop in water pressure at your home. This is fairly normal as the network has more properties to supply with less water (greater demand). Essentially more people are being supplied from a Waste Water District.
It can also cause slightly coloured water at your tap. This is due to the pressure difference causing sediment to be disturbed. It often passes after a few minutes if you run the tap.
How come not everyone gets their water back after a rezone?
More often than not a rezone means the water returns to all those affected. Sometimes, however, a minority of people don’t see their supply return following the rezone. This is usually because the burst main is located to close to your home.
It is important to understand the different types of mains that make up our network. We have different types of mains; strategic mains which carry large volumes of water around the region, often moving water to reservoirs; distribution mains which move the water around more local areas (such as the Waste Water Districts); and finally supply/ communication pipes which supply your home.
The valves need to perform a rezone may be located to close to your home for the rezone to supply your home. If this is the case you will need to wait until the main can be fixed. This is usually done in less than three hours.