The case of Davies & Ors v Gold Coast City Council [2021] QDC 135 concerned a claim in private nuisance to the District Court of Queensland (Court) by property owners (Plaintiffs) against the Gold Coast City Council (Council) in respect of subsidence allegedly caused by the Council's stormwater pipe in an easement in favour of the Council that is over part of the Plaintiffs' property (Subject Land).

The Council argued that the Plaintiffs had constructed a retaining wall which had caused the stormwater pipe to break and that was in breach of the terms of the easement. 

The Court firstly determined if the Plaintiffs were in breach of the terms of the easement, and if not, how the damage to the Subject Land was caused and the party responsible for the damage. 

The Court held that the Council was liable in private nuisance for the following reasons:

• The Plaintiffs did not breach the terms of the easement by constructing the retaining wall. 

• The Council was responsible for fixing the broken stormwater pipe, and it was the broken stormwater pipe that caused the subsidence to the Subject Land. 

• The Council’s failure to repair the broken stormwater pipe and the resultant subsidence was a material interference with the Plaintiffs' reasonable enjoyment of the Subject Land and amounted to liability in private nuisance. 

The stormwater pipe conveys stormwater into a canal next to the Subject Land. The stormwater pipe exits through a retaining wall inclusive of a headwall, cut-off wall underneath the stormwater pipe outlet, two concrete wings around the stormwater pipe outlet, and a concrete apron underneath the stormwater pipe outlet wings. The retaining wall was constructed by the Plaintiffs and is adjacent to a larger revetment wall bordering the entire width of the Subject Land that faces the canal. 

The Council argued that the construction of the retaining wall caused the stormwater pipe to break, and the Plaintiffs constructed the retaining wall without the Council’s approval. 

The Plaintiffs did not produce any approved plans for the construction of the retaining wall. Instead, the Plaintiffs relied upon the evidence of the tradesman who constructed the retaining wall to establish that the Council approved its construction. 

The Court held that the absence of approved plans at trial did not preclude a finding that the retaining wall was approved for the following reasons: 

• The evidence provided by the tradesman was clear and persuasive about his recollection of events and, in particular, he was able to recollect the names of the relevant Council inspectors. 

• The original building approval for the dwelling showed the retaining wall. 

• The Council's records were inconclusive, and a reasonable inference could be drawn that the approval of the retaining wall was misplaced or lost. 

The Court was therefore satisfied that the Council had approved the construction of the retaining wall. 

The Council argued that the retaining wall was in breach of the terms of the easement because it did not allow "…full and free right and liberty to enter upon the easement land for all purposes incidental to maintenance of the drainage…" (at [86]). 

The Court considered the following principle in Brown v Jackson [2015] QSC 355 (at [16]) in respect of construing an easement dealing with a situation where obstructing the easement in any way was prohibited:

"Generally, unless there is a provision to the contrary, a right of way easement which is sufficiently wide to permit its purpose will not prevent the servient owner from fencing the easement, with the dominant owner accessing the right of way by means of gates at such points as reasonably meet his or her requirements."

The Court distinguished the facts and circumstances in Brown v Jackson [2015] QSC 355 from the drainage easement in this case by finding that the entirely underground stormwater drain in this case was not comparable to a gate that interfered with access to a driveway. The Court held that the retaining wall did not prevent the Council from using the easement for the intended drainage and maintenance purposes. 

The Court held that the Plaintiffs were not in breach of the terms of the easement for the following reasons:

• The terms of the drainage easement did not prohibit the construction of a retaining wall.

• Since the Court found the retaining wall was approved by the Council, the Plaintiffs could not be in breach of the terms of the easement. 

The Court considered what had caused the subsidence of the Subject Land. The Court heard expert opinion evidence from the Plaintiffs' structural and geotechnical engineering experts, which demonstrated that a loss of sand backfills in and around the stormwater pipe and stormwater pipe outlet structure was the main cause of the subsidence.

The Council conceded that it was responsible for the stormwater pipe, but not for the stormwater pipe outlet structure in the Plaintiffs' retaining wall. 

The Court held that the Council was as responsible for the stormwater pipe outlet structure as it was for the stormwater pipe itself. As a question of fact, the stormwater pipe could not be separated from the stormwater pipe outlet structure. The stormwater pipe outlet structure performs the essential tasks of facilitating the stormwater in the stormwater pipe to disgorge into the canal and retains the engineering bedding of the stormwater pipe. 

Because the stormwater pipe and stormwater pipe outlet structure are inseparable, the Court concluded the following:

• The stormwater pipe outlet structure was an essential element of the Council’s stormwater system within the easement. 

• The Council was responsible for the matters causing the loss of sand backfill. 

• The Plaintiffs bear no responsibility for the causation of the subsidence of the Subject Land despite the infrastructure being located on the Plaintiffs' property. 

The Court relied on the following principle in Turner v Kubiak [2020] QDC 223 to determine what amounts to a private nuisance (see [60] to [63]):

"A mere interference that causes damage does not constitute a nuisance. A balance has to be achieved between the right of an occupier to do as they desire with their own land and the right of their neighbour not to be interfered with…However, to be actionable as a nuisance, the interference…must be both substantial and unreasonable…
 
[What is] unreasonable involves weighing the respective rights of the parties in the use of their properties."

The Plaintiffs submitted that whether there had been a private nuisance depended on the authority granted by the terms of the easement to interfere with the Plaintiffs' enjoyment of the Subject Land. The Court agreed and found that the terms of the easement granted the authority for the Council to use and maintain the stormwater pipe, but it did not authorise the Council to either: 

• unreasonably interfere with the Plaintiffs’ use and occupancy of the Subject Land; or

• cause, create, or contribute to any physical damage to the Subject Land.

Therefore, the Court was satisfied that the Council’s actions amounted to private nuisance for the following reasons: 

• The loss of backfill in and around the stormwater pipe and stormwater pipe outlet structure was the fault of the Council and it had caused the subsidence on the Subject Land. 

• The subsidence on the Subject Land was a substantial and an unreasonable interference with the use of the Subject Land. 

• Even though the Council did not install the stormwater pipe outlet structure, the Council had failed to take reasonable steps to remedy the nuisance since it became aware of the existence of the nuisance in November 2012. 

The Court gave judgment for the Plaintiffs and held that the Council was liable in private nuisance. The Court made the following orders: 

• An injunction requiring the Council to remove or replace the stormwater pipe or alternatively requiring the Council to carry out remediation work. 

• An order that the Council pay to the Plaintiffs general damages of $50,000 for the loss of use and enjoyment of the Subject Land. 

• An order that the Council pay to the Plaintiffs special damages of $110,108 for the repairs to the Plaintiffs' retaining wall.