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James Debono
The over-extraction of ground water in Malta is leading to an unsustainable situation in a number of ground water bodies suffering depletion, as more and more private individuals are extracting the water through illegal boreholes.
The private extraction of ground water now amounts to more than half the total supply being extracted every year in Malta and Gozo.
Ground water extraction is also double the limit sets by the draft water policy of 2004. Most of the water is being extracted by illegal boreholes used for irrigation purposes, but the figure also includes extraction from old wells (spejjer) registered before 1943.
Sources told MaltaToday the amount of water extracted from old wells is negligible. A number of post-1943 boreholes are registered but this does not mean that they are legal.
Of the total 33 million cubic metres extracted annually from Malta’s ground water, an estimated 17.5 million are extracted by private sources, sources told this newspaper.
According to the ‘Water Policy for the Future’ consultation document published in 2004, the average amount of renewable groundwater per inhabitant is estimated at 40 cubic metres per year.
At a population of 380,000 inhabitants this results in a national renewable groundwater quantity of 15.2 million cubic metres every year – less than half the amount of water being extracted today.
Any extraction higher than this safe yield could result in the deterioration of ground water through seawater intrusion. And the extraction of ground water is already estimated to be equal to the recharge of the aquifers from rainwater.
Replying to a parliamentary question, resources minister Ninu Zammit said that the balance between extraction and refill from rainwater amounts to 1 million cubic metres.
According to Malta Resources Authority chief executive Antoine Riolo, the one million cubic metres balance mentioned by the minister falls within the margin of error of the study, in a way that one can safely say that in most underwater bodies the amount of ground water extracted is equal to the recharge from rainwater.
“Holistically, the estimated current total abstraction from the aquifers is comparable to the total potential annual groundwater yield from the aquifers,” Riolo says.
But he also warned that “regional hot-spots do exist where the localised recharge abstraction situation may not be sustainable in the long-term.”
The amount of water penetrating the aquifer amounts to 32 per cent of the rain falling in Malta.
jdebono@mediatoday.com.mt
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