Storm water outfall should be located at Ta’ Barkat –MEPA experts

The EPD has advised the MEPA Board that any shifting of the outlet location onto a more virgin site on the coast would trigger a negative recommendation on the whole project.

The new storm water outfall is required by the National Flood Relief Project aimed at the prevention or minimisation of flash floods caused by heavy storms which usually recur once every five years.

This will ensure that the depth of run-off in the effected streets will not surpass the 10cm mark.

The EPD welcomed the fact that the flood relief project will alleviatein the Wied il-Ghajn valley mouth and urban areas in the south of Malta.

But it expressed concern about the proposed engineering solution, which would divert half of the Wied il-Ghajn natural valley flow to an outfall located in the predominantly natural coast between Xghajra and Zonqor.

“This would result in the permanent defacement of undeveloped natural rocky coast to accommodate a new tunnel outlet,” the EPD warned.

Initially, the EPD called for the extension of an existing dam and reservoir in Wied il-Ghajn to store the water in this location.

But this solution was shot down by the Coordinator of the Environment Impact Assessment for the project because the existing 5,000m3 reservoir does not have the capacity to contain the 200,000m3 of runoff generated by one storm. Enlarging this reservoir was deemed not to be possible because of lack of space in the valley.

In its final report, the EPD still expresses the concern that the project seeks the rapid discharge of accumulated runoff directly to sea, “with hardly any attempt at rainwater harvesting” but came to accept the need for the outfall.

What remained of major concern was the location of the tunnel exit was a major concern.

The EPD is convinced that Ta’ Barkat is the only spot along the northeast-facing coast between Xghajra and Zonqor where a new breach in the natural coast can be considered as being acceptable in principle.

Although a continuation of the natural coast, this part of the coast is irreversibly dominated by the massive sewage treatment plant and its ancillary coastal developments such as the main pumping station, the sewage outfall and the extensive remodeling of the pre-existing topography.

Ironically, the previously pristine Ta’ Barkat site was chosen as the site for the new sewage treatment plant after the original location in Xghajra had to be abandoned because of its proximity to the Smart City project.

On the other hand, the EPD warns that any other alternative location on the same coast would result in an unacceptable freestanding intrusion in the open coastal landscape.

The proposed project consists of a tunnel which follows an L-shaped route to divert run-off from Zabbar and parts of Triq Wied il-Ghajn to Ta’ Barkat near the sewage treatment plant.

Culverts in different roads will feed the tunnel, which will be equipped with grit separation equipment to minimise oil contamination of the rainwater before reaching the sea.

According to the EIS, the elimination of flooding in Marsaskala would make the development of a Yacht Marina in this location easier.