How can we ensure the world has enough fresh water?

Robert A. Heinlein addressed this type of topic in many of his stories of space exploration and colonization. In space oxygen / breathing air and potable water are valuable and scarce commodities, and since they have to be manufactured through recycling – which costs fuel and energy resources – they are always “paid for” by the consumers. The ugly fact made plain in such novels is that in space if you can’t afford to pay for the air you breathe and the water you drink then you can’t be there, and you’ll have to go back Earthside… if you can live long enough to get there.

So one way to provide drinking water where it is needed is to value it more than it already is by charging its replacement cost – plus profit – for it. The benefit of Earth over space is that the planet does have ways to produce, channel and recapture water that might otherwise be ignored. Producers respond to market incentives. That’s why most of us can take relatively short trips to incredibly well-stocked supermarkets and buy food from around the planet: because food is not treated as a “free resource” and producers have arisen – all over the planet – to produce and transport and distribute exactly what we want, at the prices we’re willing to pay.

As you correctly note, water is one of the most freely available resources on the planet, and for that very reason has always been considered “free”. It’s not. We need to explicitly recognize its value by allowing producers to charge what the market will bear. In some places, that’s going to make living so costly that people will more naturally avoid those areas for more favorable market conditions – or it will spur producers to find a way to produce the necessary resource at better and better prices (as competition spurs them to find less and less expensive ways to produce and still make profits that attract them to the business in the first place), making places that are now only marginally able to carry human populations more capable – and richer all around.

At some times, that’s also going to mean that potable water is more valuable than at other times. Our metered water prices should reflect that fact. Prohibitions on car washing and lawn watering are useless; charging people the replacement cost for the water they choose to expend will drive home its value to all consumers.

Stop having too many babies.

While it is not a long-term solution I think every house should collect rainwater, even if only to water the garden or flush the toilet or use in the washing machine, it should be compulsory for new houses to be built with the capacity to collect rainwater, an obvious no-brainer to me.

I agree with @Adagio. I think each new housing development and business complex should have water storage as part of the design. Even if it’s just for garden watering, toilet flushing and the like there is roof space or space under carparks and the like that could be used to collect water. We were in drought for years and it made us very conscious of not wasting water.

At any point in time, some part of Australia is in drought. So the state of Victoria is building a desalination plant. It seems like a good idea but as with most projects of its kind, is deeply mired in political arguments and budgetary problems. Still with so much salt water about, it seems like it might be a solution.

There are different solutions for different situations. A few that I like especially well: remove silly laws against reusing your greywater (water that has been used once, such as for showering, but not water from the toilet or from washing dishes) which can be used a second time to flush toilets, water the garden, or run through a cultivated wetlands system. Desalination in areas where this can be done pretty well with the heat of the sun. Water conservation and retention areas in dry places, done well, can create lakes and ponds and re-green the place, making the land all around it likelier to retain water rather than have it run off too quickly before it can recharge aquifers. Switch to more dry-land farming, because Big Ag is a prime user and waster of water. Drip irrigation instead of spraying water into the air to reach plants, so it can scatter and evaporate.

We’re pretty wasteful of water right now because it seemed endless and we learned that wasting resources for convenience is acceptable. But if we own up to the waste and buckle down, we could be OK.

We can save a bunch of water by personal awareness and conservation, but many times as much water is used per capita on manufacturing and food production.
55 gallons for a cup of coffee (includes watering the plant).
10 gallons for a slice of bread.
A liter of bottled water takes 4 liters of water to produce, not including making the bottle.

Changing what we consume and how can make a huge difference.

I think this is a fabulous idea and I’m sure the concept will be developed further as time progresses, there must be infinite ways of improving on things we use every day, go industrial designers!

@Adagio – Now call me a germaphobe or whatever, but I don’t like the idea of standing over top of the toilet to wash my hands. However the idea itself is good. It would be easy enough to plumb toilets so that the gray water from the sink is drained directly into the toilet tank to use for flushing.

@rooeytoo oh yes, germaphobe alright : ^)

As far as rainwater goes, some areas with consistent rainfall collect enough for all their needs. On the island of Saba each house/building has a huge cistern beneath it, and a roof that collects the rain.

In Chicago they are exploring a different approach, allow the rainwater to get into the ground. In most cities there the rain hits pavement and that is treated as a problem, the water gets channelled into gutters and storm drains and to the sea or into the sewerage system. Chicago is trying out porous pavement that will let the water settle right through it into the water table.
In a city like Los Angeles that is more than 20% paved over for cars, and where rain comes in infrequent torrents, it could make some sense to get the water into the ground instead of coursing down the side of the road or hillside.

The world does have enough fresh water. Far more than even 10 billion people would ever need.

The issue is this: the inexpensive availability of fresh water where people live.

Recently, I’ve read about an interesting proposal:

1) Develop smart green transportation systems
2) Move farming to areas with plenty of water
3) Reuse grey water in dry regions (toilets etc)
4) Use green desalination facility in dry areas to produce water for washing and personal hygiene (showers etc)
3) Use scarce fresh water resources in dry areas as drinking water only