Turning the Tide in Nelson: Up‑Flo Filter Supports Cleaner Urban Waterways
A Growing City, Rising Stormwater Pressures
Nelson’s coastal environment is one of Aotearoa’s most valued natural assets — but rapid urban development is increasing the volume of stormwater runoff entering local waterways. During rainfall events, runoff can carry fine sediments, hydrocarbons, heavy metals, and organic contaminants into sensitive marine ecosystems.
To protect Nelson’s water quality, the project team required a stormwater treatment system that could deliver reliable, high‑performance results within a compact footprint.
The Challenge: Effective Treatment in a Constrained Urban Site
The development needed a solution capable of removing:
- Fine sediments
- Heavy metals
- Hydrocarbons
- Organics and organic‑bound bacteria
- General stormwater contaminants
The treatment device also had to integrate seamlessly into the site layout while meeting Nelson City Council’s stormwater quality expectations.
The Solution: Up‑Flo® Filter in a Hynds Precast Chamber
A 15‑module Up‑Flo® Filter was selected for the project and installed within a Hynds precast concrete chamber.
The Up‑Flo® Filter provides:
- A patented upwards‑flow treatment path for maximum media contact
- A drain‑down system that prevents standing water
- High pollutant‑removal efficiency across a range of flows
- A compact, modular design ideal for tight urban spaces
Stormwater is directed into the chamber, passes upward through the filter media bags, and is treated before entering the stormwater network.
Image source Hynds
Local Delivery Through Strong Collaboration
The installation was delivered by Hynds and the project team, who managed the manufacture, delivery, and onsite placement of the chamber. Hynds supplied an 2550 mm diameter manhole fitted with 15 Up‑Flo® Filter modules, ensuring durability, structural integrity, and straightforward access for future maintenance.
The system was installed efficiently, demonstrating the value of combining Hydro International’s treatment technology with Hynds’ local infrastructure expertise.
Outcomes: Reliable Treatment for a Sensitive Environment
- The Up‑Flo® Filter now provides the site with:
- Effective removal of key stormwater contaminants
- Consistent performance under variable flow conditions
- A durable, low‑maintenance treatment system
- Compliance support for regional water‑quality requirements
- This installation contributes to protecting Nelson’s waterways and supporting sustainable urban development.
Image source Hynds
Proud Partners in New Zealand
Hydro International’s partnership with Hynds ensures that advanced stormwater treatment technologies — including the Up‑Flo® Filter — are delivered efficiently and supported locally across Aotearoa.
Together, we’re helping safeguard the region’s natural environment for future generations.
Want to know more?
Explore how the Up‑Flo® Filter delivers high‑performance stormwater treatment across New Zealand and worldwide.