How much water is leaking from our pipes?

In the third in a 4-part series we find out how much water is used, how much is lost to leaks, and how the city is working to find them.

These various technical gizmos on top of a pressure reducing valve measure the amount of water passing through

These various technical gizmos on top of a pressure reducing valve measure the amount of water passing through

I am taking a closer look at Cranbrook’s water system with Director of Public Works Joe McGowan. We started at Phillips Reservoir, where our water is stored before being sent to homes and businesses. Then we visited some of the 13 pressure-reducing stations in the city that make it safe to turn on our taps. Most recently, we drove around Cranbrook, visiting areas where our pipes are in the worst shape, parts of town that Joe likened to a popcorn popper because of all the ruptures.

Now, Joe is telling me what the city is doing to find all of the problem areas and start the process of reducing the leaks.

Each of the 19,125 people in Cranbrook uses 387 litres a day. Last year, Cranbrook as a whole used 4,402 mega litres of water.

Each year, Cranbrook performs a water audit. An audit report presented in February found that in 2012, Cranbrook lost four times as much water due to leakage as it would if the water distribution system was in good shape.

Statistics gathered across the developed world indicate that each time a water main bursts, it takes on average six days to repair, allowing time to learn there’s a leak, to find the leak, and repair the leak. In those six days, 576 cubic metres of water will leak out.

The same survey indicates that if it’s a service pipe from the main to the home, it takes longer to repair: 60 days to learn about the leak, 14 days to locate it, and one day to repair. In that time, 720 cubic metres of water will be lost.

Even if the pipes were brand new, we would still lose water. Every water system loses 10 per cent of the water that passes through it, Joe explains.

“No matter how well you install a water system, you are going to lose about 10 per cent. You can never overcome that on a big system. Nothing is perfect – it’s unavoidable.

“The water loss above that is what we are going after – the unaccountable. That’s the stuff that disappears and we don’t know where it is going.”

It might seem that Cranbrook is losing vast quantities of water, but compared to other communities in the Kootenays it’s about average.

According to Columbia Basin Trust, in 2009 more than 40 per cent of all the water produced in the Kootenays was lost, equating to 5,037 Olympic sized swimming pools every year.

Compared to Cranbrook, which loses 33 per cent of its water to leakage, Fernie and Kimberley lose more than 70 per cent of their water, Sparwood about 60 per cent and Elkford 56 per cent.

To help combat the problem, Columbia Basin Trust launched a WaterSmart initiative, where municipalities sign on to reduce water consumption by 20 per cent by 2015.

Cranbrook signed on in March 2010, and is taking several steps to reduce the amount of water escaping from our system.

“If something is going to break, it’s going to break at the weakest point,” says Joe. “The question is: what can we do to maintain the quality we have and extend its life span?

“We are identifying the points in the city’s water distribution system that are most susceptible to failure.”

The city is partnering with four companies with niche experience to scour the water system, looking for problem areas.

There are eight steps to take to reduce the amount of water Cranbrook loses. First is the water audit, which tells the city how much water should be used, and how much is being lost. Next, utilities crews conduct visual surveys to look for obvious signs of leakage, such as water showing up on a road, yard or ditch.

Then they start breaking the city down area by area.

“We determine how much water goes in and how much water comes out of a defined area between 2 and 4 a.m.,” says Joe, adding that the time frame is chosen because fewer people are using water then. “We look at how much is being used versus how much should be used based on the number of properties in that zone. That tells you in relative terms where you are losing water.”

When they find an area that is losing more water than expected, the area is broken down again and again until they can isolate a small area that is losing a significant amount of water.

“Now that we have identified a bad area, we put a meter there permanently and watch it,” says Joe.

Check out Thursday’s Townsman for the fourth and final part of “Under Pressure”, where we look at a simple but clever way the city is decreasing the amount of water leaking from our pipes.