01-40_WC_149_JUL-AUG26_PT - Flipbook - Page 24
INFRASTRUCTURE
Flooded with Evidence
How forensic investigations shape water main break disputes
BY EDWARD POON
WATER MAIN BREAKS every two
minutes on average in the United States
and Canada. When it bursts, the visible
geyser is only the beginning. Behind the
scenes, municipalities must navigate a
maze of interconnected pipes, complex logistics,
and aging infrastructure to prevent a chain reaction of floods, sinkholes, and property damage.
Isolating a break is more complicated than it
appears, as is determining the cause of the failure.
Because shutting off water flow is rarely as
simple as turning a valve, water main breaks
can cause substantial damage to homes and
buildings, personal and business assets, electrical
and mechanical systems, and roads and sidewalks.
As a result, disputes often arise over who will
ultimately be liable for these losses. Given the
many considerations at play (e.g., physical
conditions, environmental stressors, external
forces, maintenance, event response), the answer
to this question typically hinges on the ability of
a forensic investigation to identify the root cause
and contributory factors.
A
Key causes of water main breaks
Water main failures are rarely sudden accidents.
More often, they are the result of aging
infrastructure under long-term stress, occasionally
combined with real-time triggering events. Most
water main breaks can be traced to a handful
of causes, each requiring technical analysis and
validation to distinguish the primary cause and, if
Edward Poon is the
Director of Canadian Forensic
Operations with HKA.
24
WATER C AN ADA • JULY/AUGUS T 2026
appropriate, one or more compounding or
contributing factors.
CORROSION AND MATERIAL FATIGUE. Regardless of
material, water mains have a natural service life of 75
to 100 years, depending on installation conditions
and maintenance. Pre-1980s cast iron and steel pipes
still in use today are particularly susceptible to both
interior and external corrosion due to water chemistry
and soil acidity. Stray electrical currents, such as those
from transit systems or improper grounding, can also
accelerate electrochemical decay in metal pipes.
Freeze-thaw fractures. In colder climates, repeated
freezing and expansion of water within or around
pipes can split pipes at weak points and create cracks,
especially in shallow or poorly insulated lines. These
fractures deepen with each seasonal cycle, creating
susceptibilities in water mains that require repair or
replacement to prevent rupture.
SOIL SETTLEMENT AND GROUND MOVEMENT. Soil behavior
is another environmental force that impacts water
mains. For example, dry soil that contracts in drought
conditions can destabilize pipe bedding. Alternatively,
expansive clay soils in wet seasons can introduce
upward or lateral pressure, stressing pipes, joints, and
couplings. Other types of ground movement related to
seismic activity, excavation, construction vibration, or
heavy traffic can shift pipe alignment or cause joints to
separate.
PRESSURE SURGES. Water distribution systems are
engineered as grid-like looped networks, enabling
water to flow from multiple directions. When valves
are opened or closed rapidly to support flow for a
firefighting operation or to accommodate a pipe
repair, for instance, a sudden spike in pressure occurs
that increases the risk of bursts, primarily where pipes
have existing vulnerabilities. The same holds true for
excessive pump cycling. The shockwaves from these
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