Last month Sydney experienced the effects of an East Coast Low with extended periods of heavy rainfall resulting in flash floods, fallen trees, collapsed power lines and damage to foundations and retaining walls.
It is common for retaining walls to be constructed between adjoining properties on different levels. Some retaining walls are quite old and do not comply with modern building standards. Who is responsible when retaining walls between adjoining properties fail?
Each case will depend on its own facts but some guidance on the way in which the courts will approach the issue is to be found in a decision of Justice Austin in Yared v Glenhurst Gardens  NSWSC 11.
The defendant was the owner of a property to the rear of the plaintiff’s property. There was a common boundary with the defendant’s property. The surface level of the defendant’s property adjoining the common boundary was four to seven metres above the surface level of plaintiff’s property. The retaining wall gave lateral support to a high embankment at the common boundary line. It was constructed according to the methods and standards in use in 1927. The boundary ran through the retaining wall.
Heavy rain fell on 7 August 1998 causing the retaining wall to partly collapse, depositing a large quantity of bricks, soil, vegetation and debris on the plaintiff’s land.
The plaintiff sued the defendant for damages alleging that fill material deposited by the defendant above and behind the retaining wall constituted a legal nuisance and that the defendant was negligent in removing trees and vegetation on its land that had held the fill material in place.
The defendant cross-claimed against the plaintiff for damages alleging that she was negligent in not maintaining the structural integrity of the wall and that it constituted a hazard on her property which she failed to abate.
The plaintiff relied on a decision of the English Court of Appeal in Leakey v National Trust  1 QB 485 which is authority for the proposition that a landowner in occupation of his land has a duty, when he is aware or ought to be aware of a hazardous condition on the land which puts the neighbouring land at risk, to take such steps as are reasonable in all the circumstances to prevent or minimise the risk of injury or damage to the neighbour’s property.
Although it was not direct authority, Justice Austin had no doubt that the principle in Leakey’s Case would be followed in this country. He commented that the retaining wall had benefited the defendant by retaining its soil and had benefited the plaintiff by maximising the use of her land and protecting her from landslip. His Honour said that while the defendant had a relevant duty under the principle in Leakey’s Case, it was not a duty to replace the retaining wall or otherwise retain its land wholly at its own expense, but it was a duty to do that which is reasonable in the circumstances, and no more or less than that.
His Honour was of the view that it was an appropriate case for the defendant to contribute an appropriate part of the cost of remedial work and to allow access to contractors so that the work could be carried out. He expressed the opinion that the defendant’s duty was to contribute one half of the reasonable cost of remedial works.
Justice Austin criticised the parties in Yared v Glenhurst Gardens for failing to reach a sensible resolution of their dispute.
Dividing Fences Act 1991
The Dividing Fences Act 1991 addresses how the cost of a dividing fence is shared between adjoining landowners. Under section 3 of the Act, a dividing fence only includes a retaining wall where the retaining wall is a foundation or support necessary to the support and maintenance of the fence.
Owners of adjoining properties will be put to considerable inconvenience and expense if they litigate a dispute about responsibility for the failure of a retaining between their properties.
They have a mutual interest in ensuring that the land on and around the common boundary of their properties is stable and that necessary remedial works to replace a retaining wall are carried out in a safe manner with a view to protecting the integrity and stability of both properties.
In most cases, adjoining owners will be better served by negotiating a sensible resolution of a dispute about responsibility for a collapsed retaining wall rather than litigating the dispute.
Foulsham and Geddes notes that this article is written for the purpose of providing generalised information and not to provide specialised legal advice. If you require qualified legal advice on anything mentioned in this article, our experienced team of solicitors at Foulsham and Geddes are here to help. Please get in touch with us on 02 9232 8033 today to make an enquiry.