UME talks groundwater issues with the Environment Agency's Darryl Lew
UME discusses groundwater issues with Darryl Lew, executive director of environment quality at Environment Agency Abu Dhabi
As overall water demand across the region continues to rise sharply, groundwater – or rather the lack of it - has been a regular talking point in the industry.
Here, UME talks with Darryl Lew of Abu Dhabi’s Environment Agency about the current groundwater situation in Abu Dhabi, and what is currently underway to improve the situation.
With a very evident arid desert climate, minimal and sporadic rainfall and no surface water bodies, it is perhaps not surprising to hear that Abu Dhabi’s groundwater aquifers record very little recharge.
“Groundwater is largely a non-renewable resource. That is because a lot of the groundwater that exists in geological strata below the ground was deposited in that geology approaching 10,000 years ago, in a different climatic regime.
It’s what is called Fossil Groundwater, and in much of Abu Dhabi there is very little – if any - recharge going on,” says Darryl Lew, Environment Agency Abu Dhabi’s executive director of environment quality.
What water there is held as groundwater is therefore under considerable pressure from the demands of agriculture and forestry, municipal and industrial uses.
Indeed the Environment Agency has said that present abstraction rates of groundwater are 25 times more than the average recharge rate, with irrigation for farming and landscaping alone accounting for a huge 72% of consumed water.
Such a situation is, of course, unsustainable, and the Environment Agency has consequently been working on a number of major initiatives to considerably reduce reliance on this fragile resource.
“One of the main parts of our action plan is that we need to make any current groundwater use as efficient as possible.
This can be achieved by efficient irrigation techniques, efficient irrigation infrastructure and good management of the precious water that we have. There are some very big gains that can be made through irrigation efficiency practices.”
In common with other parts of the wider industry, the use of recycled water for irrigation purposes present some very significant opportunities to reduce reliance on groundwater reserves.
“A lot of the groundwater could be replaced and not used, in favour of utilising recycled wastewater. This water has been treated to a very high standard for the use of irrigation. If we use the water that is not currently being used, we can reduce the demand on the groundwater. Recycled water is a resource that needs to be used in this kind of climate.”
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With the Environment Agency finding that only 55% of recycled wastewater was used for irrigation in 2009, there is clearly scope for some very significant savings through this technique. At the same time, recycling another currently wasted resource holds some similarly promising prospects.
“Another investment that the Abu Dhabi government is making is around the reinjection of its desalinated water which, at times, is in excess of the needs of the emirate. When the summer demand is very high and the combined cycle power stations are running at full load, a by-product of the process is the desalinated water. So instead of discharging that back in to the Gulf, we’re looking at taking that water and artificially recharging it through artificially constructed recharge basins, and then into the groundwater system.
“They are currently doing that at a site just outside Liwa in the Western Region, and it’s the biggest scheme of its kind in the world. We’re about a year to eighteen months away from finishing construction, and then artificial recharge will start.”
The scale of the project is certainly striking, with around 1.7 billion litres injected into the aquifer in 2012 – boosting emergency water reserves for the emirate from 30 to 90 days. With other schemes – including pilot solar desalination plants and changing the irrigation delivery methods in agriculture - there is clearly a growing practical response to the groundwater issue.
“What we are really saying is that we need to conserve our groundwater as much as possible, as that is our water security as an emirate. The overarching principle with water consumption, efficiency and demand management, is that we need to make sure that we are not using more that we need to of any kind of water. When you have demand-side controls in place, you ensure that the different sources of water are meeting those demands. And groundwater should be the one that is drawn on last of all.”