Making the most of water – rainwater harvesting
Given the difficult growing conditions this year, now might be a good time to consider utilising rainwater harvesting on your yard. Terry Finch from our sustainability partner ADAS Equine explains the benefits.
Benefits of rainwater harvesting
As temperatures rise and we are less able to predict weather pattens, it makes sense to make better use of the free, and mostly sustainable, supply of water that falls fairly regularly in the UK.
Rainfall totals for winter 2024/2025 and spring 2025 were below average across all regions with the Met Office recording the second driest on record in England.However the annual average rainfall in the UK amounts to 1160mm, so why not make better use of some of that?
You do not need to be licenced to harvest rainwater as long as it does not harm the environment, i.e. it should not adversely affect normal watercourse flows.
We previously discussed the many ways we use water on our yards, for drinking, soaking feed, washing down etc, to significantly reduce your metered water bills. Rainwater has a balanced pH and is free of the treatments found in mains water, horses and other livestock will generally favour the rainwater over mains where they have a choice.
Things to think about:
- How much water do you use and where is the biggest need?
- Do you have a suitable collection area?
- What quality of water do you need?
- How much rainfall do you have?
- What is the cost of installing a rainfall collection system?
The amount of water you can collect will depend on where you can most easily collect it from, generally the easiest way is from a roofed area.
It is worth making sure your guttering is clean and in good condition and also checking your roofing materials before considering installing a collection system. For example, it would not be recommended, to install a collection system on a roof made of asbestos sheets where contamination could potentially occur.
Tanks come in many sizes from 150 litres upwards. Tanks are best darkened to prevent light encouraging algae growth in the water whilst in storage. The recommendation would normally be to have capacity for up to 2-3 months’ worth of rain, but even collecting relatively small amounts could still be beneficial.
Think carefully about where you locate your storage tank/s - both for convenience of use, but also in relation to managing any excess water in high rainfall periods and where any overflow pathways may run.
Filter out any debris to prevent sediment - this can be as simple as some fish net stocking or fly rug material on the inlet to the tank. The majority of water tanks come with raised outlets to allow sediment to collect below, which can be periodically emptied for cleaning.
Complete filter kits are available for larger systems, as well as pumps that can be helpful to divert water to where you need it most.
Covering white containers reduces discolouration
Horses do not need the collected water to be treated; how often do we see them favour the pond over the clean bucket? However, it is a good idea occasionally empty out your tanks for a good clean. If you have capacity and the need, ultra-violet light treatment can be used to produce potable water (safe for human consumption).
For smaller yards with less roof capacity, you can still benefit from collecting your rainwater without spending lots of money. Simple water butts with connection kits are available for under £50 and can easily be set up to divert water off relatively small roof areas or even field shelters to feed water troughs or be used for hay soaking or washing down. Having multiple collection points and co-locating with field water troughs can also be helpful and reduce labour for watering horses where there is no mains supply available.
You can take sustainability even further by repurposing containers such as clean IBCs and blue barrels that have been used for food transportation. IBCs can collect 1m3 of water, and they can be stacked to increase storage capacity in a small space, whilst blue barrels can be connected together to increase capacity. These items can be found second hand on the internet and are a relatively low-cost way to store water.
If you have large, roofed buildings, barns, stables or arenas, or are interested in more complex systems, you can speak to a rainfall harvesting company who will calculate for you the potential amount of rainfall collection possible from your buildings and the volume of storage that you might need and will recommend the best system for your circumstances. (Free to use calculators are also available online.)
Here are our key takeaways
- Have a walk around your yard, look at your existing roof space and gutters and see what might be possible
- The cleaner the water going into your tank the better
- Clean your gutters and roofs if necessary
- Filter out debris and sediment when collecting rainwater
- Excluding light will reduce algal build up keeping your water clearer
- Save labour and water costs through making a few small changes
For more detail have a look at the Environment Agency guidance available on the Ecosystems Direct website.