Saturday, July 08, 2006

“The thirsty earth soaks up the rain / And drinks, and gapes for drink again.” So wrote the poet Abraham Cowley in 1656. Last year, France suffered la Sécheresse (a drought) pretty much all over. When we were looking for somewhere to settle, one of the criteria we considered was the climate: and Brittany looked wet enough to grow our veggies.

However, just when all our young plants were trying to establish themselves, last month just 24mm of rain fell into our rain gauge, whereas the average (according to the official France Meteo website (and click on “Caractéristiques climatiques”) is 42mm. For July, 37mm is expected and, on Tuesday, we recorded a massive 32mm. With another 9mm overnight, we are already over the “target”.

Whilst we and the local farmers are pleased to see the rain, having so much fall all at once onto baked hard earth isn’t ideal as most will run-off without infiltrating. What we need to do is find someway of smoothing out these peaks and troughs of supply and avoid having to use expensive, treated tap water to water the garden: rainwater harvesting is the thing. Looking around at some of the options, the infrastructure and cost is daunting: huge great plastic tanks needing to be buried in the ground, pipes, pumps and filters and all at a cost which suggests a payback in decades.

Cobbling together a budget solution (for about 1/5th of the cost of a ready made system) we’ve bought a 1000 litre (220 gallon) tank and built a support to raise it up to avoid the need for a pump. We just need to buy a filter, which I’m researching at the moment, then connect it all up and hope for some more rain. For a really pragmatic approach to all things watery, and the formulae to calculate how big a storage tank you need relative to size of roof and water requirement, I cannot recommend Judith Thornton’s book The Water Book highly enough.

For another perspective on permaculture from a different part of the globe (Texas, USA) check out “Trailer Park Girl’s” blog .