Water: Floods and Droughts

There’s two real problems with water – too much, and too little.

Too much water can be due to heavy rainfall (remember, wet places are predicted to get wetter) which leaves water lying on fields, running off roads, over-filling rivers and reservoirs. That’s the problem in the UK at the moment – more than 200% of the usual monthly rainfall has fallen in some places, and as a result low-lying areas in Somerset have reverted to the marshland they were, centuries ago before our ancestors drained them. The soil is so saturated that new rain just runs straight off into the rivers, so they’ve risen to record levels in some places – the river Severn in Worcester on the 13th February 2014 stood at 18 feet and 7 inches (5.67m) of water, a new record.

There is a silver lining to this soggy cloud – the heavy rains have replenished aquifers depleted by years of insufficient rain for the demands made on them in the past few decades and the south of the UK shouldn’t need to worry about droughts affecting drinking water supplies for a year or two.

All the same, the water blanketing fields ruins crops and grazing land, forces farmers to use vital forage supplies to feed livestock penned on higher ground instead of the beasts being out grazing, disrupts services for people living in those areas as roads are submerged, enters houses and ruins the contents.

Similarly, storm surges can drive far higher sea-levels to overtop coastal defences, flood coastal lands, destroy infrastructure and property. In due course, sea-level rise will do the same thing more gradually and less dramatically.

If you can’t move out of the way of a flood, you can at least take steps to mitigate the effects. There’s plenty of official advice on the web – such as the Environment Agency’s suggestions, here. I would just add that if you’re relying on your own power source to power a pump during flooding, don’t put your genny where the floods might reach it. That’s what went wrong at Fukashima dai-ichi…..

The opposite problem is not enough water, either because there isn’t enough rain to maintain groundwater and river supply, or because there’s too many people chasing a limited supply. Droughts in the UK aren’t usually all that severe at present but hosepipe bans and irrigation restrictions are fairly regularly put in place in dry summers, and in the future a warming world is very likely to make heatwaves and droughts more common in summer (Dry places will get drier!) There’s nothing we can do about making more rain fall out of the sky, but we can mitigate the effects of droughts and over-demand by conserving water, restricting the amount of water we use and finding alternative sources of water.

A common way to start as a survivalist is to hoard plastic bottles, jerrycans or barrels of water, carefully rotating them every 2 years or so to keep the water fresh, and storing supplies of thin bleach and/or chlorine tablets to sterilise stored water. It’s a start, but in all honesty, if we’re facing a summer like, say, 1979 when it didn’t rain for months, most people won’t be able to store the hundreds of litres of water required to keep even a small nuclear family alive, let alone water the garden or flush the loo. Water is heavy and if you pile 100 litres of water (enough water for 4 people to drink 2 litres each per day for just under one month), you’re putting 100kg of stress on the floorboards. It’s also bulky and can’t be compressed. You also need more than 2 litres per person per day, because that’s just your drinking water. What about cooking, washing, laundry, hygiene?

Can you keep it outside? Well, up to a point. In cold winters water outdoors may freeze, which will cause it to expand and burst its container. It’s still heavy, bulky and turns green with algae if it’s exposed to the light. If you live in a flat or shared property, though, you may not have an outside in which to safely keep it.

We have water butts in the garden that – at present – are used for watering the garden in dry weather and for watering the livestock. These capture water off the roofs of the outbuildings via downspout linkages on the guttering, enabling us to store rainwater from wet times and use it when we need it in dry times. That reduces our demand on local mains supply and means we can ignore hosepipe bans. If we needed to, we could bring in water from the garden butts and run it through a water filter (a British Berkefeld, or Big Berky, lives in the kitchen) to render it entirely fit to drink.

The Berky will cheerfully accept a bucket of water from a roadside ditch at the top and dribble out potable water at the bottom (I know it will, I’ve done it. And fished out a few stray tadpoles, too) – having a good filter and spare filter elements in hand is a very useful precaution for many different scenarios, from water contaminated with volcanic ash to having to acquire water from unconventional sources. I bought mine a few years ago when I was travelling the country widely in a converted camper-van and needed to be able to keep myself and the dogs supplied with clean water without access to the mains supply. There are many good filters on the market – at the moment I would say the cream of the crop are the Berky and the US-made Sawyer filters, but shop around and try to match what you buy to your own personal circumstances.

When there’s a shortage of water, it’s well worth putting a large brick in the cistern of your toilet to reduce the amount of water that’s used on each flush. A sealed bag filled with water will also do the job! If you have an old-fashioned cistern that uses gallons of water every time, consider replacing with a modern, more efficient design. In serious shortages, remember that you’re flushing your toilet with drinking water and stop flushing from the cistern – you can easily flush the loo with left-over water from laundry or washing-up, recycling your water more efficiently. You can also use ‘grey’ water that’s been used for cooking, washing or washing up to water the garden, rather than using drinking-quality water.

At the ultimate end of the drive to conserve water lies the composting toilet, which doesn’t use water to flush at all. If you’re interested in this subject (and for many reasons we should all think about it!) then the Humanure Handbook is the go-to source of info.

All this is on a personal level. What can we do to reduce water use outside the house? There’s a lot we can do via our shopping lists – buy locally sourced foods so you’re not responsible for importing food that’s grown by irrigation in tropical or subtropical dry countries. Crops like maize (sweetcorn) use a lot of water when they’re growing, so when we buy a tin of sweetcorn, we’re effectively importing that water from the country that the corn grew in. It’s possible to look up the amount of water that different crops use (so-called ’embedded water’) in sites like this one – you might be amazed how much hidden water you’re using!

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