By Hana Namrouqa

AMMAN – Overpumping of water from the Azraq Basin for drinking and irrigation purposes is raising salinity levels at the aquifer, a recently released study indicated.

The basin, which supplies Amman with 17 million cubic metres (mcm) of potable water annually and 43mcm for irrigation, is showing signs of salinisation and depletion, according to the study, released by the International Union for the Conservation of Nature this week.

“The Azraq Basin supplies Amman with excellent drinking water, but due to overpumping from the Amman Water and Sewage Authority (AWSA) well field, as well as from farm wells, the water level has dropped dramatically and signs of salinisation are starting to occur,” the study indicated.

Spread over 75 square kilometres and located 100 kilometres east of the capital, the Azraq Wetland is home to marshlands, natural pools and streams that attract thousands of birds each year.

But excessive extraction of water from the wetland, which started in 1980, has caused water levels to drop by 12-15 metres below the surface, leaving only 0.04 per cent of the marshland that was once rich with flora and fauna, according to experts.

The wetland receives its water from the Azraq joint basin, 94 per cent of which is located in Jordan, 5 per cent in Syria and 1 per cent in Saudi Arabia. The wetland is fed by three main springs that produce 20mcm each year, according to ecologists.

Severe drawdown in the AWSA well field caused a reverse in the hydraulic gradient and consequently, the saltwater in the centre of the basin, locally referred to as qaa (mudflat), started to move in the direction of the well field, according to Ali El Naqa, a hydrogeology professor at the Hashemite University who carried out the study.

“Wells adjacent to the qaa are showing a continuous increase in salinity. The geophysical model indicates that if the present abstraction rates continue, around 66mcm per year, the saltwater will continue to move,” he told The Jordan Times on Thursday.

Saline water is expected to reach the AWSA well field in between 500 to 2,000 years, the professor said.

“Movement of underground water is slow and there are barriers slowing down the saline water’s mixture with the fresh water, but this doesn’t mean the signs should be ignored and current overpumping continues,” Naqa underscored.

In its “pessimistic prediction scenarios”, the study indicated that any increase in pumping from the AWSA well field or in the area north of it, will cause severe drawdown and depletion of several wells in the area in the east and centre of Azraq where the sprigs are located.

“An abstraction quantity of 16-18mcm per year is the safe limit which the Ministry of Water and Irrigation should allow… currently more than the double is being pumped,” the professor noted.

The study recommended installing underground sensors to monitor the groundwater level fluctuation as well as the concentration of ions that contributes to the salinity, such as chloride and sodium.

Once saltwater intrusion occurs it is almost impossible to reverse it, the study said, underscoring that mitigation strategies designed to slow or halt the rate of saltwater intrusion can be expensive but are necessary to protect the water resources from more damage.

The study also urged the Ministry of Water and Irrigation to encourage Azraq residents to extract the high-saline water and produce salt, as well as to reduce pumping from government-owned wells to prevent salt water intrusion in the AWSA well field.