Porous Lane Case Study: Driveway, Henderson Valley
The Henderson Valley property had long been affected by persistent water pooling and stormwater management challenges during multiple Auckland weather events. These issues were intensified by the presence of an active stream emerging across the site, making traditional driveway construction and impervious surfaces unsuitable.
Through a connection made at the Water New Zealand Conference, Watersmart assessed how Porous Lane, the 2025 Stormwater Innovation of the Year Award winner, could be integrated as a resilient, water-sensitive solution tailored to the site’s unique conditions.
Watersmart provided technical expertise and product supply, supporting the installation of Porous Lane permeable paving to effectively manage stormwater while maintaining the durability required for vehicle traffic. Porous Lane Accredited contractors Siteworks Ltd lead the main civil works and installation of the Porous Lane driveway. Given the soft ground conditions, a geotextile cloth was installed across the driveway footprint to stabilise the subgrade. A robust, layered base was then constructed to ensure long-term performance, consisting of:
100mm of GAP40, mechanically compacted for structural strength
100mm of GAP20, mechanically compacted to create a stable bedding layer
To further control subsurface and edge water movement, a Nova Coil drainage system was installed along the driveway and connected to the existing cesspit, providing reliable conveyance during heavy rainfall events.
Despite the challenges posed by soft ground, active water flows, and vehicle loading requirements, the project delivered a durable and future-focused outcome. Through careful base preparation, integrated drainage design, and the use of a permeable paving system, stormwater is now managed on site without increasing runoff.
Key Achievements
Significantly improved stormwater management during extreme weather events
Elimination of surface water pooling across the driveway
Successful application of an award-winning permeable paving system in a residential setting
A resilient, water-sensitive solution aligned with best-practice stormwater management