Many thanks to Craig who has shared with us his solution for harvesting water in his wood.

One of the main problems at our wood is a lack of water. We bring drinking water in aquarolls but as we stay for upto three weeks ferrying washing water in was impractical. I used to bring 400 litres in barrels 45 miles but the cost in diesel was crippling. We found a solution on the internet used in Africa called a biosand filter. As we were only using the water for washing and washing up we used fine play sand as the filter media. If you search biosand filter you can find out all the technical info as well as how you can make a filter suitable for making drinking water.

It all starts with an outdoor workshop roof where we collect rainwater through a filter which removes a large amount of vegetable matter.

Next the water is stored in an IBC (1000 litre tank) .It passes from here into the sand filter, the outlet of the sand filter has to be higher than the upper level of the sand so the filter never dries out. (some element of the biology needs to stay wet and not freeze!) so the pipe rises to the inlet on the second IBC.It is then fed via a float valve into a clean water stroage tank. Because of the fittings we can only store 800 litres of clean and 800 litres of dirty water.

This system provides us with plenty of filtered water for washing and washing up. I have drunk from it but don’t usually as it can be stored for long periods. The tanks are painted black to keep sunlight out, which can cause algae to form.

As far as maintenance goes, onces a year I clear the top couple of inches of sand off. As you can see from the photos the muck only goes an inch or so through the sand and a little further at the edges. In winter we have cut dead bracken and filled the enclosure to isulate the filter. It has been in service three years now and still seems to be performing well.