Environmental Engineering Reference
In-Depth Information
Table 20.13.
Dam safety inspections as recommended by ANCOLD (2003).
Type of inspection
Personnel
Purpose
Comprehensive
Dams engineer and
The identification of deficiencies by a thorough onsite
specialists
1
(where
inspection; by evaluating surveillance data; and by
relevant)
applying current criteria and prevailing knowledge.
Equipment should be test operated to identify
deficiencies. For a safety review consider:
- Draining of outlet works for internal inspection;
- Diver inspection of submerged structures.
Intermediate
Dams engineer
The identification of deficiencies by visual examination
of the dam and review of surveillance data against
prevailing knowledge with recommendations for
corrective actions.
Equipment is inspected but not necessarily operated.
Routine dam safety
Inspector
The identification and report of deficiencies, by
structured observation of the dam and surrounds, by an
inspector, other than the operator, with recommendations
for corrective actions.
Routine visual
Operations personnel
The identification and report of deficiencies by visual
observation of the dam by operating personnel as part of
their duties at the dam.
Special/emergency
Dams engineer and
The examination of a particular feature of a dam for
specialists
1
some special reason (e.g. after earthquakes, heavy floods,
rapid drawdown, emergency situation) to determine the
need for pre-emptive or corrective actions.
Note:
1
Examples of specialists include mechanical and electrical engineers, to inspect outlet works, spillway gates
and automated systems, and corrosion engineers).
Table 20.14.
Frequency of inspection for dams with no known deficiency (adapted from ANCOLD, 2003).
Inspection type
Consequence of
Routine dam
Routine
failure
3
Comprehensive
Intermediate
safety
visual
Special
Daily
1
Extreme
On first filling then
Annual
Monthly
As required
5 yearly
Daily
1
to
High A, B, C
On first filling then
Annual
Monthly
As required
5 yearly
tri-weekly
Significant
On first filling then
Annual to
3-Monthly
Twice weekly
As required
5 yearly
2-Yearly
to weekly
Low
On first filling,
Monthly
As required
then 5 yearly
Very low
Dam owner's
Dam owner's
As required
responsibility
2
responsibility
2
Notes:
1
Dam owners may undertake a review to determine if a reduced or increased frequency of inspection is
acceptable. The review should be carried out by a dams engineer and take into account such matters as
Regulator requirements, dam consequences of failure and risk, type and size of dam, dam failure modes and
monitoring arrangements.
2
Monthly routine visual inspections and 5 yearly intermediate inspections with test operation of equipment
and review of consequences of failure category are suggested.
3
See Section 8.2.3 for definitions of the consequences of failure.
