Plans for flood water tunnel spanning the island

The government is planning a vast underground tunnel network that would capture and distribute flood water and treated waste water across the island in a bid to wean the country off its unhealthy dependence on the water table.

The €70 million system is also expected to resolve Msida and Birkirkara's flooding problems and lead to substantial savings on the country's desalination bill.

The project, which is still on the drawing board, is likely to be submitted for prospective EU funding within a couple of months, following cost/benefit analyses studies and environmental impact assessments, the Resources and Infrastructure Ministry has told this newspaper.

The idea is to link Malta's three major flood water catchment areas - Marsa, Salina and Birkirkara - with a network of underground tunnels that would start roughly in Xemxija and end in Xghajra, where the system would be connected to the planned sewage treatment plant.

From there, the tunnels would distribute the water to different areas where it can be used primarily for agricultural purposes.

The system would complement a series of infrastructural works that have been carried out over the past few years to deal with floodwater in Marsa and in Burmarrad. It would also provide a solution for the flood-prone areas of Birkirkara and Msida.

Originally, the plan was to have a series of large, underwater reservoirs built in Birkirkara, as an alternative to water courses, which are impossible to build in the area because of the level of development.

Eventually, however, the option of developing a network was explored and preliminary cost/benefit analyses showed that the system could be viable.

But besides enhancing the country's flood prevention infrastructure, the tunnel system's primary role would be to "harvest" flood water, making good use of it and providing a solution to the rampant extraction currently taking place from the water table.

The government estimates that some 20 million gallons of water are being extracted from the water table each day, roughly six million gallons more than is regarded to be sustainable for its natural replenishment. Of those 20 million gallons, some 10 million are used as potable water while the rest are used for agricultural purposes.

The government believes that its project would radically change this situation. The Xghajra plant alone is expected to produce an estimated 10 million gallons of water per day from treated sewage while, based on provisional estimates, the tunnels would be able to store and deliver massive amounts of floodwater annually. Studies have shown for instance that freak heavy storms have, in the Birkirkara catchment area alone, produced some 160 million gallons of water in a single day. So far, all this water ends up in the sea.

On the one hand, Malta's agricultural needs would be satisfied, which means that water extracted from the water table can be used exclusively as potable water and maintained at a strict 14 million gallons per day. On the other hand, close to 10 million gallons of water per day could be saved from the desalination process, bringing about significant energy savings.

Resources and Infrastructure Minister Ninu Zammit would not go into the specifics of the project, saying it was too early. He did emphasise, however, that preliminary costings were positive.

If implemented, the prospect of finally making good use of flood water is excellent news for any country. In Malta's case however, as a recent report by the United Nation's Intergovernmental Panel on Climate Change highlighted, energy security and the depletion of the water table are among Malta's most pressing climate change-related issues.

The ministry has been criticised for not doing enough to deal with illegal extraction of water and for not having yet delivered a water policy.

On this point, however, Mr Zammit insisted yesterday that the government's flood prevention programme always had the long-term aim of aiding in the country's water management. The watercourses built were designed to trap water in certain areas precisely to have the water seep into the water table in those areas, thus replenishing it.

"That was the first phase, which dealt with the basics. Now we are moving on to managing the water we can now control in a more efficient manner," he said.

There is no date yet for the publication of the water policy but the minister pledges to tackle illegal water extraction once agriculture is given a viable, alternative source of water.

"The truth is that if we prohibit certain farmers from extracting water we would be jeopardising their livelihood and pushing the price of their produce up."

After 1987, he continued, the government's priority was to provide an adequate supply of good quality potable water, which it did through a massive investment in desalination plants and a reliable distribution network, as well as the upgrading of the entire infrastructure in a way that would mitigate losses.

In recent years, attention has turned to trying to ease the flooding in the catchment areas of Wied il-Kbir (from Buskett to Qormi/Marsa) and Wied il-Ghasel (from Dingli to Burmarrad).

"The next logical step now is harvesting second class water, particularly from the central catchment area of the island (Birkarkara, Msida, Balzan, Lija, etc)."