Outdoor Taps, Irrigation And Garden Plumbing

Indoor leaks announce themselves. Outdoor leaks just run into the ground, and the first evidence is a water bill that has climbed for no obvious reason.

The garden tap

The most common outdoor leak, and the easiest to ignore.

A dripping garden tap wastes more water than people expect, and because it drips onto soil or a drain, nobody sees it.

The usual causes are a perished washer, a worn spindle, or a tap that has been overtightened for years by people trying to stop the drip. Mounting is the other issue: a tap fixed to render or loose brickwork gets levered every time a hose is connected, and eventually it cracks the pipe behind the wall. That leak is inside the wall and it is a much bigger job.

A tap that wobbles when you turn it needs fixing before it starts leaking, not after.

Backflow prevention

Any outdoor tap that a hose can be left in, particularly one near a garden, a pool or a wash bay, needs backflow protection.

The risk is real: a drop in mains pressure can siphon water back into the supply, and anything the hose end is sitting in comes with it.

On a residential building this is usually a simple device at the tap. On larger properties and anywhere with irrigation, it is a testable device with an annual inspection requirement. Where it applies and has never been tested, that is a compliance gap rather than a maintenance one.

Irrigation systems

Irrigation is the most common source of invisible water loss on a strata property.

Solenoid valves stick open. The zone runs continuously instead of on its schedule. Because it runs at night, nobody sees it, and the garden just looks well watered.

Underground pipe damage. Roots, ground movement, or a spade during landscaping. The water goes straight into the soil.

Broken sprinkler heads. Run over by a mower, snapped off, or pushed out of alignment so the zone waters a wall.

Controllers that were never adjusted. Set once at installation and never changed, so the system waters through winter and through rain at the same rate as January.

A rain sensor is the cheapest fix available and it is missing from most systems.

Finding the leak

This is where [water meters and sub-metering](/blog/water-meters-sub-metering-and-leak-detection) earn their place.

Shut every outlet, then watch the meter. If it is still moving, water is going somewhere.

Isolate the irrigation separately and repeat. That one test tells you whether the loss is inside the building or outside it, and it takes ten minutes.

On a property with no isolation to the garden system, add it. Being able to shut irrigation without shutting the building is worth having before the day you need it.

Drainage is the other half

Water arriving at the building is as much of a problem as water leaking out of it.

Surface falls that run toward a wall rather than away from it. Blocked stormwater pits. Downpipes discharging beside a foundation instead of into the drainage system. Garden beds built up above the damp course, which puts wet soil against the wall.

Each of those drives moisture into the building, and the symptom turns up inside as rising damp or failed render. The [blocked drain](/blog/blocked-drains-and-what-the-blockage-tells-you) that matters most is often the one outside.

The seasonal check worth doing

Before summer, test every zone and watch it run. Look for heads that are broken, misdirected or buried.

Check the controller schedule against the season, and fit a rain sensor if there is not one.

Check every outdoor tap for drips and for movement in the mounting.

Read the meter with everything off.

It is an hour of work. On a property with gardens it routinely finds more water than anything else on the maintenance list.