About 18 million litres of water a day—enough to fill around 30 Alexandra swimming pools—will be supplied to Alexandra and Clyde by the Lake Dunstan Water Supply. So how do we make sure the pipelines can carry the weight of all that water?
“Once the pipes are in the ground, we regularly pressure test them as part of quality assurance—to check they are leak-free and safe to carry the amount of water that will be flowing through them,” says CODC Senior Project Engineer Kevin Furnival.
The crews have been pressure testing pipes over the past couple of weeks, all with good results.
Pressure testing involves filling the pipes with water once both ends are capped off. Pressure is applied, forcing any trapped air out of the pipe. Once stabilised, further pressure is applied.
Fulton Hogan foreperson Maurie McDonald checks the pressure gauge during pressure testing
of a Clyde wastewater pipe. The gauge logs pressure data, holding it until the project management team download the data for checking.