Rain Activ is an exciting opportunity, both to large developers and self builders alike. The system has succeeded in reducing SuDS costs during planning, purchase and installation.
The tanks come in a range of sizes from 1,500 litres to 15,000 litres.
As well as simply reducing costs, Rain Activ far outperforms its competitors in numerous key areas:
- Industry leading, ultra low storm water discharge rates.
- Professional calibration.
- Arrives to site fully assembled and ready to install.
- No moving or consumable parts, fully self-cleaning.
- Discharge rate calibrated between 0.05 - 1.95 litre per second
- Add rainwater harvesting for a very small extra cost
How Does Rain Activ Work?
Rain Activ utilises a simple to install, pre-assembled, shallow dig rainwater storage tank, along with a self cleaning filter and a controlled discharge valve. Rainwater from the roof is heavily filtered as it enters the tank, removing any particles larger than 1mm. Once the rainwater reaches a set point within the tank it is discharged at a controlled rate. Due to the quality of filtration involved, a very small orifice can be used without the risk of blockage. For this reason, Rain Activ can provide industry-leading rates of discharge as low as 0.05 litres per second.
Every system sold is bespoke, and calibrated to each site’s requirements. Our engineers use Micro Drainage™ hydraulic modelling software to ensure the system discharges at the desired peak rate during a storm event. As the system already contains various key components, such as the tank and high quality filtration, the addition of a submersible pump and management system turns the system into a full domestic rainwater harvesting system.
Ultra Low Discharge rates
Rain Activ delivers new industry low levels of storm water discharge. The systems can be calibrated to provide a calculated discharge value as low as 0.05 litres per second up to 2 litres per second dependant on site requirement. With discharge levels this low, Rain Activ provides a solution for sites that have previously found meeting storm attenuation criteria difficult or impossible. These include:
- Smaller developments (1-10 homes) where the rate of storm water is not great enough for effective use of vortex flow control.
- Greenfield sites.
- Sites with very low discharge rates stipulated by planning.
- Contaminated sites.
*Fully enclosed system with a max excavation depth of 1.5m
Rain Activ produces a much flatter discharge curve than other storm attenuation systems. This means the system can help reduce stress on the drainage network over a greater range of storm, rather than being calibrated to one specific event.
Calibrating Rain Activ
Our design team calibrates every Rain Activ bespoke to site requirement; both the peak discharge rate and volume of attenuation. Our extensive hydraulic modelling, lab testing and field testing provides academically supported data in order to calibrate the system correctly.
- Required run off rate.
- Roof size.
- Geographical location.
- Potential water usage (if combining with Rainwater Harvesting).
Using the data provided above, our experts use Micro Drainage™ hydraulic modelling software to test the system and provide documentation ready for immediate submission to planning authorities.
Please call our sales team with the information above to allow us to specify the correct system on 01733 405 111.
Easy To Install
The F-line flat tank can be installed into much higher water tables than a standard round tank. If you don't know what your water table will be like in the winter, you're safer to install a flat tank.
The F-Line tanks are flat and the installation depth is 60% less than other rainwater tanks. The excavation can be up to 70% less, meaning little earth excavation, easy handling and less cost for you! The small excavation pit is easily filled in and your garden will look just like it did before.

Technical Details
Tank Size in Litres |
1500 |
3000 |
5000 |
7500 |
Weight Kg |
80 |
170 |
250 |
310 |
Length |
1200 |
2400 |
2960 |
3340 |
Width |
2400 |
2400 |
2220 |
2310 |
Overall Height* |
1015 - 1415 |
1015 - 1415 |
1350 - 1750 |
1415 - 1815 |
Ground to Invert** |
335 - 735 |
335 - 735 |
335 - 735 |
330 - 730 |
Excavation
Tank Size in Litres |
1500 |
3000 |
5000 |
7500 |
Length |
1600 |
2800 |
3360 |
3740 |
Width |
2800 |
2800 |
2620 |
2710 |
Overall Height* |
1115 - 1515 |
1115 - 1515 |
1450 - 1850 |
1515 - 1915 |
*Overall height allows for 100mm compacted aggregate
**Using a VS60 (635mm Shaft)
The overall height difference above is because up to 400mm can be cut off the 635mm shaft on site so as to achieve your exact invert level.