Irrigation leak detection in Tempe

The City of Tempe runs its own urban flood irrigation service, delivering Salt River Project water to seventeen city parks and around eight hundred and fifty residential customers, and maintaining more than thirty-seven miles of irrigation mains and over a thousand irrigation valves. Nowhere else we work is organised like that.

Irrigation leak detection in Tempe usually means working out whether water is being lost on the city's delivery side or on the private side of your own valve, in a network whose delivery times and shut-down months are published.

Every figure here is the City of Tempe's own published description of its urban flood irrigation service.

How does Tempe's delivery schedule help diagnose a leak?

It gives every symptom a timestamp to be checked against. Residential deliveries begin at ten at night on Sunday and can take several days to complete, so ground that is saturated early in the week and drying by the weekend is behaving exactly as it should.

Ground that stays saturated through a dry stretch, or in November and December when no irrigation water is delivered at all, is not behaving like a delivery. That is the point at which a pressurised line, a pool, or something under the house becomes the more likely explanation.

Where does the city's system end and yours begin?

At your valve. The city maintains the mains and the valves that make up the delivery network; what happens to the water after it is turned into your property — the berms, the grading, the private pipe and the containment — is yours to manage.

So a leak that shows up as water escaping the lot boundary, or failing to spread across the yard it was meant to flood, is generally on the private side of that line, and that is the side we work on.

What is different about a flood system compared with a sprinkler system?

The water is not continuously pressurised, so the classic signs of a pressurised leak — a meter creeping round, a constant wet patch, an audible escape — mostly do not apply. A flood system misbehaves in the shape of the delivery instead: water going the wrong way, arriving short, or pooling where it should drain.

Watching an actual delivery is therefore worth more than any equipment. What the water does in the first hour tells you where the route has failed.

Does a rented property complicate it?

It changes who can act rather than what is found. Owner-occupancy in Tempe is 42 percent, the second lowest of any area we cover, so the person watching the water go the wrong way is frequently a tenant. The finding goes in writing with photographs so it reaches whoever owns the property and the diagnosis is not repeated.