Vast African water source found

[summer]

BBC

By Matt McGrath
Science reporter, BBC World Service

A newly discovered water source in Namibia could have a major impact on development in the driest country in sub-Saharan Africa.

Estimates suggest the aquifer could supply the north of the country for 400 years at current rates of consumption.

Scientists say the water is up to 10,000 years old but is cleaner to drink than many modern sources.

However, there are concerns that unauthorised drilling could threaten the new supply.

Huge resource

For the people of northern Namibia water is something that they either have too much of or too little.

The 800,000 people who live in the area depend for their drinking water on a 40-year-old canal that brings the scarce resource across the border from Angola.

Over the past decade the Namibian government have been trying to tackle the lack of a sustainable supply in partnership with researchers from Germany and other EU countries.

They have now identified a new aquifer called Ohangwena II, which flows under the boundary between Angola and Namibia.

On the Namibian side of the border it covers an area roughly 70 km by 40 km (43 miles by 25 miles).

According to project manager Martin Quinger, from the German federal institute for geoscience and natural resources (BGR), it's a substantial body of water.

"The amount of stored water would equal the current supply of this area in northern Namibia for 400 years, which has about 40 percent of the nation's population."

"What we are aiming at is a sustainable water supply so we only extract the amount of water that is being recharged.

"What we can say is that the huge amount of stored water is will always be enough for a back up for an area that is currently supplied only by surface water."


Test drilling on the new aquifer
This region is dependent on two rivers for its water supply. But this has restricted agricultural development to areas close to these water sources. Mr Quinger says that the new aquifer has great potential to change the nature of farming in the area.

"For the rural water supply the water will be well suited for irrigation and stock watering, the possibilities that we open with this alternative resource are quite massive." he explains.

As well as providing a new source for agriculture in a region the aquifer will augment existing potable supplies. Martin Quinger says the discovery may be up to 10,000 years old but it is still good to drink.

"If the water [has spent] 10,000 years underground, it means it was recharged at a time when environmental pollution was not yet an issue, so on average it can be a lot better than water that infiltrates in cycles of months or years."

Dangerous drilling

The natural pressure that the water is under means that it is easy and cheap to extract. But because a smaller salty aquifer sits on top of the new find it raises the possibility that unauthorised drilling could threaten the quality of the water.

Martin Quinger says that random drilling into the aquifer could be dangerous.

"If people don't comply with our technical recommendations they might create a hydraulic shortcut between the two aquifers which might lead to the salty water from the upper one contaminating the deep one or vice versa."

One of the biggest advantages of the new aquifer could be in helping people cope with climate change.

The researchers estimate that it could act as a natural buffer for up to 15 years of drought.

As well as identifying the new water source a key aim for the researchers involved is to develop the capacity among young Namibians to manage their country's water resources before the funding from the EU runs out.

[Daria Morgandorffer]

Wow, that's fascinating. I'm frankly shocked that something of this magnitude hadn't already been discovered- aren't there fairly sophisticated ways of locating large water sources these days?

[Deleted]

Jul 20, 2012 13:50:10 GMT -5 Daria Morgandorffer said:

Wow, that's fascinating. I'm frankly shocked that something of this magnitude hadn't already been discovered- aren't there fairly sophisticated ways of locating large water sources these days?

You would think so.
Either way, thats awesome.

[darnkatz]

Jul 20, 2012 13:50:39 GMT -5 asdfjkl said:

All they need is oil and then we'll give a shit about them.

I just spewed smoothie every where. Well played.

[hawkeye]

Ok, I need a scientist in here to explain this to me.

The water is 10,000 years old? How can that be? They also said it flows- it must be flowing into some other body of water somewhere right?

God, I feel like a moron.

[Daria Morgandorffer]

Jul 20, 2012 13:50:39 GMT -5 asdfjkl said:

All they need is oil and then we'll give a shit about them.

I dunno, I hear blue is the new black

[downtoearth]

Jul 20, 2012 13:52:24 GMT -5 hawkeye said:

Ok, I need a scientist in here to explain this to me.

The water is 10,000 years old? How can that be? They also said it flows- it must be flowing into some other body of water somewhere right?

God, I feel like a moron.

I'm not sure in this case, but it could be a very deep perched aquifer, which means water collects on a low permeability zone (silt/clay layer) at very deep levels, which often is not connected to the surface. Here's a picture with a couple perched aquifers below ground.

Water can still "flow" in the perched aquifers as they are recharged from far above and the water flows out off the edges or downward through the silt/clay layer at very slow rates.



That's only one criteria, but if it's 10,000 years old, I'd guess this.

[downtoearth]

Jul 20, 2012 13:54:44 GMT -5 Daria Morgandorffer said:

Jul 20, 2012 13:50:39 GMT -5 asdfjkl said:

All they need is oil and then we'll give a shit about them.

I dunno, I hear blue is the new black

I agree, but sometimes I think I should have stayed in water resources instead of remediation.

[Deleted]

Jul 20, 2012 13:52:24 GMT -5 hawkeye said:

Ok, I need a scientist in here to explain this to me.

The water is 10,000 years old? How can that be? They also said it flows- it must be flowing into some other body of water somewhere right?

God, I feel like a moron.

It sounds like it is a deep aquifer. Water moves really slowly once you get down deep - but it does move. Most water ends up going horizontally through shallower aquifers, but a small portion will go deeper and hit this. All water moves "downhill" toward the ocean, but some of it goes very slowly.

[pixy0stix]

This is amazing!

[Daria Morgandorffer]

Jul 20, 2012 13:59:09 GMT -5 asdfjkl said:

Jul 20, 2012 13:54:44 GMT -5 Daria Morgandorffer said:

I dunno, I hear blue is the new black

I'm actually pretty sure that water right are going to be like super fucking important in the next 20 years or so. I play to put a lot of my 401(k) stock into water purification and detection technologies. As soon as I figure out what those are.

But I do think this is really cool. Not to undermine the importance of it as it relates to quality of life for Nambians, but I'm curious whether 10,000 year old water would contain minerals, elements, life forms that would be worth researching from a scientific perspective.

Yup. Living in Phoenix for 8 years really opened up my eyes to water rights issues. It's going to get right nasty in the Southwest over the next few decades.

[arborgold]

Water rights are actually already really important in a lot of places. I wrote an article in law school about water rights in Botswana.

[bhnumbers]

Is this the kind if thing where in 30 years the Nile or some other major source is going to dry up and people are going to be like "oooooh, that's what that water went to?"

Eta: clearly I know nothing about this stuff, I just can't wrap my brain around it...