Your Dam Your Responsibility (PDF~1.2MB)

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4 Planning to Build a Dam
4.2 Services of an Engineer
Because of the size and nature of many farm dams, and because construction of most
farm dams looks deceptively simple and uses familiar technology, it is tempting to think
that the services of a professional engineer are not required. This is often a mistake.
Not only is it true that a significant proportion of farm dams fail, but did you know that a
high percentage of dams fail during their first filling, especially in Victoria? This generally
means the design, construction or filling rate of the dam was an aspect that was not
understood.
One of the key reasons for such a failure is the properties of dispersive clay soils.
Rapid wetting of the compacted embankment can cause the micro-particles of clay to
disintegrate. Detailed assessment of this problem is usually outside the expertise of farm
dam owners. There are also other reasons for such failures.
An experienced dam engineer carrying out the dam design and supervising the
construction is beneficial because the structure will be properly designed and built to
current industry standards. The cost of engineering services should be a minor percentage
of the total cost of the work. More importantly, that cost is very small when compared
to the cost of reconstructing the dam if it fails, not to mention the additional cost of
compensation for the damage caused by the failure.
Note also that relatively few engineers are experienced in dam design and/or construction
supervision, and you should take care to ensure that the engineer that you select to
design or supervise the construction of your dam is a suitably qualified engineer. Also
make sure that the engineer whom you select has an adequate track record of experience
in dams of a size and type which is relevant to you, including experience with earth
materials found in Victoria.
A suitably qualified engineer is a professional engineer who:
a) has qualifications sufficient for eligibility for membership of Engineers Australia;
b) is recognized by the engineering profession as experienced in the engineering of dams;
c) is competent to undertake the investigation, design, construction supervision, repair
and remedial work, operational, surveillance, maintenance and decommissioning
activities associated with farm dams; and
d) has an appropriate amount of professional indemnity insurance.
A competent and experienced dam engineer would be able to demonstrate:
1. A sound knowledge of relevant dam design principles and methods to ensure safety,
economy and durability;
2. An appreciation of local meteorological, hydrological and geological conditions;
3. A knowledge and understanding of current industry practices and standards with
respect to dams; and
4. A broad knowledge of other factors which might be relevant in particular situations,
including knowledge of legal obligations under the Water Act and awareness of such
potential problems as siltation, wave action, other forms of erosion, and pollution.
When selecting an engineering service, make sure that the engineer’s level of
professional indemnity insurance is sufficient to match the cost of the work and the
consequences of failure. This is not only in the engineer’s interests, it is also in yours.