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Municipal Water Mains · Narrowing the search

Step Testing & Zone Isolation for BC utilities.

Close valves in a planned sequence, watch the zone meter, and the leak tells you which segment it lives in. Step testing is the old, unglamorous, devastatingly effective way to shrink a leaky zone to a few hundred metres of main — before acoustic crews finish the job.

Night ops
Run at minimum demand
Segment-level
Loss isolated per step
L/hr
Quantified per segment

Free phone consult · No pressure · Mon–Sat 8am–6pm PT

Why utilities choose it

Built for

High-MNF zones where loggers haven't convergedQuiet leaks on plastic mains defeating acousticsQuantifying loss per segment for repair-vs-replace callsConfirming a zone is clean after disputed repairs

How it runs

  1. 1

    Test design

    The zone's valves are mapped into a closing sequence that isolates segments progressively, with customer impact assessed — step tests run at night partly so that brief, planned isolations pass unnoticed. Critical users are identified beforehand.

  2. 2

    Night execution

    With the zone meter logging, valves close step by step. Each closure that drops the inflow by more than the expected demand of the isolated segment has just located leakage inside it — quantified in litres per hour, live.

  3. 3

    Segment ranking

    By morning the zone's loss is allocated across segments: this 400-metre run carries the bulk of it, those streets are clean. The search area collapsed from a zone to a block.

  4. 4

    Acoustic finish

    Correlation and ground mic work pinpoint within the guilty segments — fast now, because the hydraulics already said where to listen. Repairs follow, and a closing meter check proves the recovery.

Ground crews + aerial screening, one company

Leak.ca has pinpointed BC water leaks on the ground since 1999 — and now screens whole corridors from the air first when the network scale justifies it. Our drone thermal water main survey ranks kilometres into suspect zones; the crews on this page turn those zones into paint marks. One accountable program from flight to dig sheet — see the full municipal water main hub.

Utilities ask

How does a step test actually find leakage?

By process of elimination, measured at the zone meter. The zone's inflow is watched while valves close in sequence, each closure isolating another segment. When a closure drops inflow by more than that segment's plausible night demand, the difference is leakage inside the segment you just isolated. It is beautifully indifferent to pipe material, depth, soil, or how quiet the leak is — if water flows to it, the meter sees it stop.

Why use step testing when acoustics exist?

Because some leaks defeat listening: deep mains, soft trench backfill swallowing noise, PVC attenuating it, or background loss spread across many small weeps no single one of which correlates. Step testing doesn't care — it counts litres. The professional pattern is hydraulic narrowing first where acoustics struggle, acoustic pinpointing inside the guilty segment after. Each method covers the other's blind spot.

Will our customers notice the test?

Designed and run properly, almost never. Isolations are brief, sequenced at minimum-demand hours, and planned around critical users (anyone on home dialysis, care facilities, process customers get specific handling). The test plan includes restoration verification — every valve confirmed reopened, the zone confirmed back to normal supply before the crew leaves. That discipline is non-negotiable.

What does the utility get out of one night of step testing?

A loss map of the zone in litres per hour per segment — which is also a repair budget in disguise: segments carrying heavy loss justify excavation or replacement; segments carrying nothing get crossed off every future search. Combined with the post-repair re-test, it's the tightest before/after accounting a leak program produces.

Related municipal services

← Municipal water main hub·Complete guide·Government programs

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