It’s trickier than you’d think, collecting rainwater. In theory at least, all you need to do is shove one end of a pipe into the end of the guttering and the other into a water butt and it will fill up with pure sweet rainwater. In the imagination the rain flows in, filling the tank in no time at all. But in practice much of our rain is of the 0.1mm per hour drizzly stuff, and so you have to be very patient and make sure that there are as few leaks as possible and finally you need to keep all the pipework as level as possible because water won’t flow uphill. As you see from the photo, my efforts to raise the water butts to the maximum possible height meant that the flexibility of the delivery pipe has introduced a bit of a dip that I’ve now levelled up with the help of a long cane and a cable tie. I won’t know how well it’s all working for a week or so, but a similarly inefficient system filled four barrels totalling 1000 litres so far this winter. But it’s worth the effort. Water is one of the principal inputs for an allotment, along with recycled compost and manure and if it’s possible to be self-sufficient in any of them, it’s all the better for the environment.
But water butts are one of the most commonly neglected items you see on allotments. They languish in the shade of a collapsing shed; sometimes with surplus water trickling from the top or more likely a lidless dump from a discontinued comfrey water experiment; the best but least attractive thing about it being to provide a breeding space for rat tailed maggots which eventually become hoverflies. Why is this? Why do we install them with our heads full of their promise and abandon them a season later? My feeling is that it’s due to the very slowness of filling and emptying them. Aside from a season like the one we’re enduring at the moment, when the water table seems to be at knee height, most seasons provide more intermittent showers than satisfying downpours and so we wait patiently until the water butt fills; unwilling actually to use it in case we need it later in the season. Then, as autumn approaches and we contemplate using the water we discover that the tiny outlet tap delivers water so slowly it takes an eternity to fill a can, and the pressure is too low to feed a soaker hose. The dilemmas accumulate. You can always bale the water out with the watering can, but if you elevate the butt to get a stronger feed you need to be 7′ tall to reach. The trick is to have two watering cans, leaving the second to fill while you use the first. Alternatively, dripper systems can function well on low pressure feeds – we use ours in the greenhouse. In practice, though, sadly it seems quicker to walk to the council provided water trough and use expensive drinking water. Watering, it turns out, is a skill that has to be learned.
On our plot we’re planning to store water wherever we can harvest it, but – and here’s the challenge – we’re on a slope. The greenhouse and the shed are at the top of the slope, so that’s fine. But there’s a big opportunity to harvest water if I build a roof to the compost bins – about fifteen square metres – but they’re at the bottom. So how do we move the water from the bottom to the top? At the moment we’ve got a petrol generator which weighs a ton and needs to be driven up from the flat; and along with a small submersible pump we can move water very efficiently if rather noisily. But I’m intrigued by the thought of lifting the water with a home-made hydraulic ram pump to move it up to the new storage system. I first saw a hydram in use in Ffestiniog, and then a friend had one in the Brecon Beacons, they’re wonderful pieces of engineering but they cost an arm and a leg if you buy a ready made. But the joy of internet searches is that there are YouTube videos galore that show how to make one with a bunch of old plumbing spares. I watched an inspiring video of an (I think) Indonesian man making a large pump and installing it in a stream with the help of friends to fill what looked like a 10,000 gallon tank – enough to supply a hamlet. I’m wondering if I could build one that’s portable so it could be moved from tank to tank …. who knows? – but if I can make water flow uphill that will be wonderful.
