How to Use Rainwater for Equestrian Needs and Save Money

There are a lot of equestrian centre and livery yard owners who are shocked by the size of their water bills. This article explains how these can be decreased.

Maybe you run a yard or a riding stable. Maybe you are lucky enough to have horses at home. Either way, you know how much water horses use. Yet from your stable roofs, or barn roof, or house roof, you could be storing litres and litres of rainwater to use instead of expensive mains water.

The horse has a pulled tendon or ligament. The vet says to hose the injured leg for 20 mins to half an hour every day. That is the same as 3 baths or a minimum of 300 litres. Or a 20 minute shower. Then there韘 the drinking water: a horse drinks 40 to 60 litres a day. And washing the feed buckets, hosing down the yard, cleaning off muddy legs not to mention shampooing and rinsing the whole horse, soaking the hay. And there韘 the yard WC being used all day long by clients and staff (eg 30 flushes a day = @ 180 litres). They may even be a washing machine for dirty numnahs and bandages. There韘 the arena to water: perhaps the sprinkler is on for an hour or two: that韘 another 1000 to 2000 litres. There are a multitude of jobs that all use water. For a yard with 10 horses, you could be using around 2000 litres a day.

All the above uses could be supplied with rainwater. With the large roof area provided by stables, barns and indoor schools, sufficient quantities of rainwater can be collected and stored for all uses that do not need drinking quality water (mains water).

The initial choice is between above or below ground storage tanks. Above ground tanks are cheaper to install as there is not the cost of digging a hole as there is for underground tanks. However, underground tanks are to be recommended as the stored water stays fresh and cool if not above ground (bacteria do not form in temperatures under 12 C) so horses will drink it more readily. It makes sense to put the tank underground, since sometimes space is very limited.

The tank should be placed in the best location to collect rainwater from the downpipes. The rainwater is cleaned, either by a filter in the downpipe, or more normally, by a filter in the tank itself. These filters require very little maintenance and remove enough debris to make the water quite suitable for all those uses that don't need human drinking--quality water.

A pump inside the storage tank takes the rainwater to where ever it is needed. The type of pump normally used can deliver up to 5 bar (household pressure is around 2.5-3.0 bar) or over 3000 litres an hour. It is certainly powerful enough to water an arena or other large area, as it can pump water up to a 45 metre head. If the pump is connected to a hose or tap, it will automatically start when this is turned on.

Another essential feature needed is a reliable mains back up that will switch automatically to mains water if the storage tank runs out.

The supplier for your rainwater system will do a tank size calculation for you, this is worked out on the average rainfall for where you live, the roof area, and what you need the rainwater for. The cost will be less in the context of a new construction when a digger and plumber may well be on site already, typically ?000 to ?000. In a retrofit, there will be additional installation costs. Specialist installers are not required. Competent builders and plumbers should be able to do the installation quite easily. The one important current building reg to meet is to ensure there is an air gap be the rainwater and mains water pipework so there can be no cross contamination.

Normally, planning permission is not necessary. However, planners now often favour building applications that include rainwater harvesting. Official pressure is on to reduce mains water consumption on the one hand and also to alleviate flood threats. Rainwater harvesting helps with both these issues. Using some of the rainwater for constructive use means less potential flood water pouring down the drains or onto land.

If you are considering using rainwater in the yard, you may also think about using it in the house. Thirty to 40% of our domestic water literally goes down the toilet or is used by the washing machine. So nearly half of our 150 litres a day of mains water could be replaced by mains water. In the house, it is energy-efficient to use a gravity-feed system with a smart header tank (such as the Rain Director). In such a system, the rainwater is pumped to a special rainwater holding header tank, and so the energy-greedy pump in the main storage tank is activated only when the header tank is empy rather than everytime, for example, a WC is flushed. This saves 8 to 10 times on electricity use. A gravity-feed system like this would not be suitable on the yard, as there would not be enough pressure for hosing down and watering.

A quote done recently for an equestrian centre wanting to use rainwater for watering 2 arenas specified either a 13000 litre capacity for just over ?000, or to be able to rely on rainwater in a drought, 26000 litre capacity for ?400 with vat and delivery.

If you are a business, you can benefit from the Enhanced Capital Allowance scheme whereby 100% of material and installation costs of rainwater harvesting systems registered on Water Technology List can be offset against tax liability.

Rainwater harvesting is clearly an option to consider in an equestrian environment. With such high water usage, the payback on the investment will make it worthwhile in 5 or 6 years.