Retaining walls are generally standard and quite easy to specify, however some sites may cause problems. These problems can include:
Retaining walls along or over easements.
Where an allowance must be made for excavation in the easement at a future date. This may mean a different type of wall other than a steel post/concrete sleeper wall (such as a gravity block wall that can be dismantled, if required), or longer than standard sleepers to span over the easement.
If your retaining wall is going to be built over an SA Water easement, it must not impede SA Water’s access to the easement, or have an impact upon any SA Water services.
Refer: Proposed Encroachment over SA Water Easements
Rock on site.
Retaining a rock wall may require a steel post/concrete sleeper wall bored and cast into the rock or a different type of wall.
As expensive as rock boring is, with the proper equipment this may be the best and cheapest option.
Alternatively, a steel-reinforced, concrete-filled blockwork wall on a concrete slab footing may suit”.