Rainwater Harvesting Ltd.
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RainWaterHarvesting Ltd.
Unit A Harrier Park
Southgate Way
Orton Southgate
01733 405100
Fax 01733 230996



Rainwater Harvesting For Farmers

The Environment Agency has issued an excellent new publication 
- Rainwater Harvesting: an on-farm guide

Payback for rainwater recycling tank and equipment in just 2 years


Farmers and Agricultural Contractors why not take the example in Environment Agency Rainwater Harvesting and On Farm Guide (2009) page 14, andFarm Tank for rainwater harvesting use the approved tank size calculator which you can find on the web here 

200 cows in the herd drinking 84 litres per day makes a demand of 6.132 million litres or 6.132 cubic metres of water a year

The roof area in the example is 3,000 square metres in a region of the UK where rainfall across the year is 700 millimetres. After 80% filter and evaporation loss (British Standard 8515) this roof will supply 1.68 million litres or 1,680 cubic metres of water a year. This is the same as an average of 4,600 litres per day.

Balancing supply and demand
The yield of the roof is not enough for drinking water for all the cows, in fact only 27% of what’s needed. But that is still mains water saved. In fact, if the demand is bigger than the supply, the tank size can be smaller because it will be emptied faster and will more often be empty to receive a new rain shower. In the EA example, this roof would give enough water for milk cooling or parlour washing. By the way, who says you can’t store the water used for milk cooling (a bit warm) and use it for floor washing later.

The tank size calculator and the standards used indicate a tank size of 96,600 litres, enough to hold the average daily supply off the roof of 4,600. 21 times 4,600 makes 96,600. The retail price of a 21,000 gallon (95,000 litre) corrugated steel tank is £2294 ex VAT. With delivery charges, fitting, filter and pump that would come to more like £3000.

The savings are 1,680 cubic metres of water a year @ £1 per cubic metre (www.water.org.uk) which makes £1,680 i.e. payback of £3000 in just 2 years (3000 divided by 1680). Payback would be even shorter after financial incentives under DEFRA’s Farming and Forestry Improvement Scheme.


Environment Agency Guide for Farmers interested in rainwater harvesting

> Download the Environment Agency Rainwater Harvesting and On Farm Guide (2009)



DEFRA Guide for Farmers interested in rainwater harvesting This scheme has closed but read more here>

Rural Development Programme for England - Farming and Forestry Improvement Scheme (FFIS)


Farm and Horticultural systems

See our Farm and Horticultural Systems here

01733 405111


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Housing Developers

Information for rainwater harvesting systems in multi-dwelling housing developments.

News & Views
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News & Exhibitions

Come and see us at thee exhibitions

Rain Director® Gains WRAS Approval!

WRAS Approved Rain Director

Rain Backup in a Box

RainWater Harvesting Ltd's innovative Rain Backup in a Box® automated mains water top ups for rainwater harvesting tanks

National Self Build and Renovation Centre

Rainwater Harvesting Exhibition Stand - National Self Build and Renovation Centre

Our permanent exhibit at the National Self Build and Renovation Centre

International Rain Water Alliance

Member of the International Rainwater Harvesting Alliance

DEFRA Water Technology List approved

WTL - we're listed


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