The Tree Nurturing System (TNS™) captures, cleans and infiltrates stormwater where it falls – cooling the city, protecting waterways, and keeping street trees alive.
Centralised pit-and-pipe drainage is built to remove water from a single point as fast as possible. Efficient at moving water – but it disrupts the natural cycle that keeps soil, waterways and trees alive.
Traditional systems collect and convey contaminants downstream, detrimentally impacting the health and function of the receiving environment.
Rainfall is piped away, leaving dead, barren soils. Groundwater falls deeper; soils lose oxygen, minerals and elements, and become hard and compacted.
The standardised approach commits cities to a significant end-of-line maintenance regime, alongside costly, time-consuming and insufficient manual irrigation.
Conventional drainage isn't climate-neutral plumbing. Every storm, it drives the very climate impacts cities are fighting – degraded waterways, urban heat, and lost water security.
Drainage flushes sediment and nutrients straight to receiving waters, where turbidity blocks light and smothers seagrass. TNS captures and filters runoff at the source, so less reaches the bay.
In Queensland, Moreton Bay's seagrass decline has been attributed largely to stormwater sediment and nutrient loads; higher sediment loads non-linearly shrink seagrass habitat.
Runoff sheets across sun-baked pavement, picks up heat, and carries it into creeks and downstream estuaries – stressing aquatic life and lowering oxygen. TNS infiltrates runoff into cool soil instead of discharging it warm.
Runoff from hot impervious surfaces can exceed 39 °C, and overseas studies document post-storm stream-temperature surges of 7–9 °C. The extension to downstream estuaries is a recognised risk pathway rather than a measured marine figure.
Draining water out of the landscape leaves no stored moisture for the evapotranspiration that cools cities, intensifying the urban heat island. TNS holds water in the soil to sustain vegetation and its cooling.
Evapotranspiration from well-watered vegetation is a core cooling mechanism in water-sensitive urban design; remove the water and you remove the cooling.
Rapid conveyance sends erosive peak flows through channels, strips groundwater recharge, and leaves streams to dry between storms – ‘urban stream syndrome’. TNS slows, stores and sinks flow to restore baseflow.
Hydrologic ‘flashiness’ from impervious catchments drives channel erosion, habitat loss and reduced dry-weather flow – a well-documented degradation syndrome.
Rain interacting with hot, low-albedo surfaces – and the pollutants mobilised off them – may amplify downstream thermal and water-quality impacts. Source control like TNS intercepts runoff before this can compound.
This is an area of active BGI research and our working hypothesis (Richards, 2023), not settled science – presented to flag a question we're investigating, not an established result.
All of it – the floods, the heat, the dying waterways – shows up on your street as one thing you can actually see.
Many urban street trees are planted in shallow graves, surrounded by hard, compacted engineered soils – root zones starved of water, oxygen and minerals. Declining immunity lets pathogens like phytophthora attack the cell structure, slowly and surely. Without a healthy root mass to hold the trunk and canopy, trees fail and collapse – and in many urban areas, that costs community lives.
Imagine a system that works like a sponge in nature. The TNS™ soaks up rainwater, cleans it, and gently releases it where it's needed most – to urban trees and plants – while letting the excess seep down to replenish groundwater. A decentralised, source-control approach: slow it, store it, sink it.
The combined systems of soil, water and vegetation – known as blue-green (living) infrastructure – moderate the release of water in heavy rainfall and provide fresh water through heatwaves. This fosters vegetation growth, expands tree canopy, and lowers urban heat.
Unlike conventional drainage, the TNS™ is a decentralised approach. That decentralisation significantly reduces the displacement of flows and volumes – mitigating rapid runoff and pollutant mobilisation by a magnitude of scale.
Source control reverses the logic of conveyance. By slowing, storing and sinking runoff, the system reconnects urban environments to natural hydrological processes.
Each unit manages its own micro-catchment. Units arrange wide or narrow, deep or shallow, independently or connected – added, removed or rearranged to suit local space, grade and site constraints.
Ideal for retrofitting existing streets without costly excavation or redesign – adapting from dense urban streets to open landscapes while holding consistent infiltration and water-quality performance.
The TNS™ distinguishes itself from other tree-pit devices through its inflow rate and its comprehensive approach to stormwater management.
An eco-friendly sponge made from special concrete. Placed along kerbsides, it cleans runoff as it flows so clean water reaches trees and plants – and filters runoff before it enters the tree pit, with treatment efficiency well above other systems. Learn more at envirokerb.com.au →
Porous media – whose voids collect oxygen, nutrients and minerals – support algae and bacteria that feed on runoff contaminants, including hydrocarbons. Intercepted under shallow sheet-flow, constituents stay microscopic, minimising accumulation and sustaining high flow-rate performance over time.
The removable-tray ESPPI protects waterways and oceans from plastic, litter and substantial pollutants. Unlike pit-and-pipe systems, gross pollutants remain in the tray of the porous kerb – so maintenance is dramatically simpler: only a street sweeper is required.
The key differentiator is the decentralised approach, which reduces the negative impacts of conventional drainage by a magnitude of scale. Through a range of proprietary stormwater-management solutions, the TNS™ is configured for both minor and major rainfall events.
Runoff retention, distributed detention and slowing the water significantly reduce flood risk, replenish groundwater, and protect downstream water systems – while maintaining ecosystem health.
How they work together: the ESPPI sits upstream to manage the first flush, with fully porous EnviroKerbs™ downstream, adjacent to it, taking the high flows. The number of units is calculated from the micro-catchment runoff calculations.
Sources: EnviroKerb™ inflow capacity from PPC Australia falling-head infiltration-cone testing (envirokerb.com.au). TNS™ treatment efficiency from MUSIC modelling, supported by multiple sources and live projects.
Matter SensAI sensors measure flow against a calibrated baseline, so a drop flags an inspection before it becomes a blockage – turning maintenance from a fixed schedule into a predictive, data-driven response.
See the full Matter integration →
Matter (watermatters.ai) – digital water-risk intelligence. BGI integrates Matter's SensAI radar-and-AI sensing for real-time stormwater and flood monitoring. See how it integrates →
Integrating proprietary modular tank, structural cell and drainage void systems – configured to depth, capacity and site type.
A street tree over a structural soil cell and tank module – fed and cleaned by the EnviroKerb™ and ESPPI.
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A grassed verge served by the EnviroKerb™, water ramp unit, tank module and drainage cell.
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EnviroKerb™ feeding a drainage cell and tank module for stormwater retention beneath the pavement.
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A planted raingarden over Rigofill ST modular blocks and RigoFlor™ geotextile.
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Water is a living system – intrinsically connected with land, culture and community. Our approach reflects the enduring principle that water should return to Country and sustain life.
Aligned with Australia's National Water Initiative (2004), the Insights Paper – Pathway to Enduring Recognition of Aboriginal Peoples' Water Interests (2022), and the forthcoming National Water Agreement.
The Tree Nurturing System (TNS™) is owned and licensed by Blue Green Infrastructure Pty Ltd. The patent is made, and the TNS™ trade mark used, under licence from BGI.
Four modular variants integrate proprietary tank, structural cell and drainage void systems – a practical bridge between policy intent and real-world implementation.
Growing national and international recognition that water is a living system – the National Water Initiative, recognition of Aboriginal Peoples' water interests, and the forthcoming National Water Agreement.
The decentralised, source-control approach reduces the negative impacts of conventional drainage by a magnitude of scale – runoff retention, distributed detention, and slowing the water.
Whether you're specifying WSUD for a council or development, or a capital partner backing climate-resilient infrastructure – start a technical conversation. We're an engineering-led company moving toward raising capital, and investment materials are available on request.
