Blue Mountain First Flush Diverter w/ Catch-All Tee
Rainwater Downpipe First Flush Diverters 80/100mm
$84.85 excl. GST
- Catch-All Tee: directs the initial runoff into the chamber & prevents bypass
- Set flush volume: simple rule-of-thumb sizing & pollution-factor guidance so you can fine-tune how much to divert.
- Proven mechanism: floating sealing ball rises and seats when the chamber is full, locking contaminated water in the chamber.
- Flexible install: mount vertical, horizontal, or in a “wet” (charged) system
- NZ-ready sizing: suits 80 mm & 100 mm downpipes commonly used in NZ.
Stop storing the dirty first flush
Cleaner tank water with Blue Mountain First Flush Diverter with Catch-All Tee.. Its self-cleaning drainage uses a slow-release valve to empty the chamber after rain, resetting your system automatically. Fine-tune performance with adjustable flush volume—just change the pipe length to divert exactly the dirty first runoff your roof sheds. Built for NZ conditions, the tough PVC body shrugs off UV, salt air and year-round weather.
Trusted first-flush performance for cleaner tank water
The Catch-All Tee design forces the dirtiest “first wash” off your roof into the diverter chamber before any water can pass to the tank—so you only store cleaner water. Ideal for new installs or upgrades on 80 mm and 100 mm downpipes common in New Zealand.
How it works?
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First rain carries dust, pollen, bird droppings, etc. into the tee.
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The Catch-All Tee directs this dirty water down into the chamber.
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As the chamber fills, the floating ball rises and seals against the seat.
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Only then can cleaner water continue to your tank; the chamber drains slowly via the outlet.
Install notes for Blue Mountain First Flush Diverter w/ Catch-All Tee (80/100 mm) — NZ
- Suitable orientations: wet (charged), vertical, horizontal. Ensure the outlet remains accessible.
- Mount at least 150 mm above ground when assembled, and follow solvent-weld steps for a watertight fit.
- Use the included flow-control washers (start with the smallest; increase size if blockages occur).
- Aqua Works tip: Pair with a leaf-screening rain head upstream to reduce debris load and maintenance.
FAQs - Blue Mountain First Flush Diverter w/ Catch-All Tee (80/100 mm) — NZ
What is a First Flush Diverter Catch-All Tee?
A downpipe-mounted first-flush diverter that improves tank water quality by isolating the dirtiest “first wash” from your roof. The built-in Catch-All Tee is shaped so no water can bypass across the tee until the first-flush chamber fills—so only the cleaner water reaches your tank.
What makes the Catch-All Tee different from a basic tee?
It’s shaped so no water can bypass across the tee until the chamber fills and the ball seals—so you harvest cleaner water.
Can I use it in a wet (charged) system?
Yes—there’s a suggested orientation for wet systems in the manual.
How big should my first-flush be?
Use the pollution factors (0.5–2 L/m²) and the 8.8 L per metre of 100 mm pipe rule to size your chamber for local conditions.
What downpipe sizes does the NZ model fit?
80 mm and 100 mm (female sockets). Model WDDP211.
What else do I need to buy?
Just the 100 mm chamber pipe (length depends on your sizing). All fittings, brackets, screen, washers, and outlet are included.
Specifications
- Brand: Rain Harvesting by Blue Mountain Co.
- Description: 80mm/100mm, pipe not included
- Code: WDDP211
Download Documents
Installation Instructions
