Downpipe Diverter

A short description of how a rain water downpipe diverter works.

A rainwater downpipe diverter is a device designed to redirect and collect rainwater run off from a building's roof into a storage container, such as a rain barrel. The diverter is typically installed along the downpipe, which is the vertical pipe that carries rainwater from the gutter to the ground.

The basic principle of a downpipe diverter involves a mechanism that can be manually or automatically adjusted to divert water either towards the storage container or allow it to flow directly down the drain. The diverter typically consists of a T-shaped connector that is inserted into the downpipe.

When the diverter is set to collect rainwater, a flap or valve within the device redirects the water flow into a hose or pipe connected to the storage container. Once the container is filled, the diverter can be adjusted to direct excess water back into the downpipe, preventing overflow. Some diverters also include a filter to screen out debris and prevent it from entering the storage container.

By using a rainwater downpipe diverter, homeowners can harness rainwater for various purposes, such as watering plants, gardening, or using the rain water as the source for the filtration system to create drinkable water. This promotes water conservation and reducing reliance on traditional water sources.

Manual Diverter

There are two types of manual diverter that are available here in England from a limited number of retailers. The main concern with a manual diverter is that it is down to you to operate it. If your away from home, you wont be able to turn it on, wasting the opportunity to fill your system.

You will also have to be the judge of how much water you should divert away from the first flush (see first flush diverter for more information about this).

The first is the “BFG Downpipe Rainwater Collector, 80mm Diameter". Available from Amazon.

The design is very simple with a tap that can be turned on or off and the price is very cheap. If your guttering system is made with the 80mm range then your good to go. This can be slotted into a 80mm downpipe with ease and your up and running. The main problem that I can see is that most gutter systems here in England are usually made from the 68mm round system or the 65mm square system.

You will need a coupling reducer to fit the unit to the downpipe. I can not find a square to round adapter, so that one is out of the question. A 80mm to 68mm reducer is what is needed, two to be precise. The first reducer will sit at the relevant height on the downpipe and then the diverter can sit in the socket, with the second reducer placed on top of the diverter and then the downpipe placed into the upside down reducer. Then you done.

The only problem is, that the 80mm to 68mm round reducer is very hard to find. There is one here:

https://guttercentre.co.uk/68mm-82mm-circular-downpipe/5676-hunter-82mm-spigot-to-68mm-socket-circular-downpipe-reducer-gr004.html

They are coming in at £4.70 each and then there will probably be a delivery charge so remember to factor that in to your budget.

The Second Manual Diverter

The second is the "Rain Water Collection Diverter, Rainwater Collector System Durable Rainwater Diverter Kit, Downpipe Rainwater Diverter Stainless Steel Rain Trap Diverter Fits 3"*4" Standard Downspout" Available at Amazon.

the diverter has a flap that can be pulled down to start diverting the water and then placed back upright to divert any water back down the downpipe.

The information states that it fits 3 and 4 inch downpipe. Again here in England we officially use the metric system, and a 3 inch pipe is equal to 75mm, which is bigger than are our usual 68mm downpipe. So adapters and reducers will be needed adding to the overall cost.

Automatic Diverter

The following is an example of an automatic diverter. The unit fits onto the downpipe and diverts the rain water through a small length of pipe into the storage tank.

Eco Trade Counter Rain Trap available from Amazon.

This is a versatile diverter, because Eco Trade state that “ Our rain diverter is designed to fit round downpipes of 63mm, 68mm, 80mm and 100mm as well as square drain pipes of 61mm and 65mm. Making this versatile for various gutter systems.”. So that would cover most peoples guttering systems here in England.

You will need to add an over flow pipe from your storage tank back to the downpipe, because this unit will divert all the water from the downpipe, so during heavy rain fall the excess water needs to be released back to the downpipe.

But for the price and versatility this is a great option for getting started and when installed correctly you can walk away of forget about it.

Automatic Diverter with Filter

The next one to look at is this automatic diverter with filter from "3p – Technik" available at Amazon currently for £58.95. which is also the best price that I could find.

They state that this will easily fit our range of guttering here in England, “Fits all UK round down-pipes from 68 to 100mm, square 65 to 75mm (not just 65 square and 68mm round).”. So that's a bonus.

It contains a a stainless steel mesh inside the unit that filters the leaves, debris and very small particles away. It can be easily removed for cleaning and maintenance. The hose outlet has a water tight seal when it is attached to the storage tank, so if it is installed at the correct height it will double up as the overflow for the tank as well.

This unit provides 3 functions as a rain water diverter, a pre-filter and the overflow for the storage tank. Making it a very useful piece of kit.