PADCA developed a residential facility called Woodgrove for the elderly on Lot 3344 Pietermaritzburg. Shortly thereafter, Redlands Development Projects developed Redlands Estate, a residential estate and business park on higher ground (Lot 321 Pietermaritzburg) that slopes down toward Woodgrove. The properties are not contiguous; they are separated by George McFarlane Lane (a municipal road) and two privately owned properties. Redlands Estate developed from 11.85% to 42.2% impervious coverage, increasing stormwater run-off. The developers installed a stormwater reticulation system that discharged water into the municipal stormwater system, which then flowed through a 600mm pipe into a canal on Woodgrove. This replaced an earlier 450mm municipal pipe. The municipality approved the stormwater plans in accordance with guidelines in force at the time. PADCA built its canal knowing it would receive stormwater from higher properties and the municipal system. The municipality had servitudes allowing it to discharge stormwater onto Woodgrove, which was subject to conditions of title requiring it to allow watercourses authorized by the municipality. PADCA claimed the increased volume and velocity of water from Redlands Estate exceeded natural flow and caused damage to Woodgrove.
The appeal was dismissed with costs, including the costs of two counsel.
A property owner who discharges stormwater into a municipal stormwater system in accordance with plans approved by the municipality and in compliance with applicable municipal guidelines acts lawfully and cannot be held liable under either the actio aquae pluviae arcendae or neighbour law for damage allegedly caused by that stormwater to lower properties. Where stormwater from multiple sources combines in a municipal system before discharging onto a lower property, and where the lower property is subject to servitudes requiring it to receive municipal stormwater and was developed with knowledge of the stormwater discharge system, the owner of the lower property cannot compel the owner of one contributing property to attenuate its discharge. The duty to take reasonable care in neighbour law does not extend beyond compliance with municipal approval conditions for stormwater disposal where the municipality is the authority responsible for assessing and managing water disposal needs for the area.
Wallis JA expressed several important observations not essential to the decision: (1) He noted considerable doubts about the availability of the actio aquae pluviae arcendae in relation to urban as opposed to rural properties, citing Roman and Roman Dutch authorities suggesting the remedy was limited to rural properties. (2) He questioned whether contiguity between properties is essential for the actio, noting that while most authorities deal with contiguous properties, some Roman law texts suggest contiguity may not always be required, though the issue of how to determine relevant proximity remains unresolved. (3) He observed that if contiguity is not required, difficult questions arise about when properties are too remote for obligations to arise, especially where discharge occurs through municipal systems. (4) He noted the illogical result if lower owners could recover from upper owners for discharging into municipal systems when they could only recover from the municipality for negligence. (5) He emphasized that negligence alone may be insufficient for neighbour law claims and that an element of unlawfulness and a duty element are required, with the reasonableness of imposing liability being central to determining when such duties arise. (6) He noted that the passages relied on from earlier cases involved the converse situation (upper owner seeking to compel lower owner to accept concentrated water) and if anything supported rather than undermined PADCA's case.
This case clarifies important principles regarding stormwater management, development rights, and the interaction between common law remedies (actio aquae pluviae arcendae and neighbour law) and modern municipal planning regulations. It establishes that compliance with municipal stormwater disposal requirements approved by the local authority constitutes lawful conduct that cannot be challenged under the actio or neighbour law. The case raises (but does not definitively resolve) important questions about whether the Roman law actio aquae pluviae arcendae applies in urban settings and whether contiguity between properties is required for the actio to be invoked. It reinforces that property owners cannot select one of many sources contributing to stormwater discharge through a municipal system and demand special attenuation measures. The judgment highlights the primacy of municipal planning authority in regulating stormwater systems and the limitations on private law remedies where development proceeds in accordance with lawful municipal approval. It also demonstrates the evolving nature of stormwater management requirements, noting that modern regulations require greater on-site attenuation than was required when Redlands Estate was developed.