Marsamxett breakwater could alter harbour circulation

Experts have called for a holistic plan to assess the cumulative impact of the various marinas and any future infrastructural developments in Marsamxett.

An Environmental Impact Assessment (EIA) on the development of a yacht marina at Sa Maison refers to the possibility of a breakwater at the mouth of the harbour warning that “this may significantly alter the circulation and flushing time of the basin”.

The idea of developing a breakwater at Marsamxett first proposed in 1969 was resurrected in a memorandum of understanding (MOU) signed between China and Malta in July last year. Subsequently the project was included in an application for EU funding presented in December.

The study conducted by ADI also claims that a new storm water outlet being constructed at Ta’ Xbiex headland as part of the National Flood Relief Plan approved in 2011, could also contribute to “cumulative negative impacts on water quality in Marsamxett”.

ADI claims that when the new outflow for storm water was approved its impact on other projects in Marsamxett Harbour was not considered in the EIA.

The study concludes that on its own the development of floating pontoons at Hay Wharf, Sa Maison, to accommodate approximately 240 new berthing spaces for yachts is deemed to have a negligible impact on water circulation and quality.

But the same EIA warns about the cumulative impact of the new storm water discharge and the other marinas in the harbour.

The EIA proposes a joint water quality monitoring programme for inner Marsamxett Harbour, to include the marinas in Msida, Ta’ Xbiex, Gzira, Manoel Island, and Sa Maison.

This should be prepared and implemented in order to continue to analyse trends in water quality, possibly as part of the environmental permit of the various marinas. 

In view of the importance of Marsamxett Habour to the economy of Malta, especially in terms of yachting, recreational navigation, tourism, and transportation, the EIA calls for a long-term plan for the harbour’s development and management. 

According to the study the configuration of the harbour with its various creeks and inlets results in a greater time for the water in the harbour to be replaced by water from outside the harbour.

“The water residence time is already high and increased and unplanned coastal developments in this harbour basin could lead to significant deterioration in the water quality, leading to negative repercussions on the viability of existing operations,” the EIA says. 

In addition, it would be advisable for one competent authority to own the model for the harbour and to be responsible for modelling of projects proposed within the harbour to ensure that new proposals do not negatively impact the use of existing facilities.

When assessing the EIA the Malta Environment and Planning Authority called for a study identifying the boat carrying capacity of the harbor, noting that similar studies have been made abroad.

ADI replied that such a study cannot be included in the EIA on a single project and if conducted should take into account the stormwater discharge outfall at Ta’ Xbiex as this could well have the “biggest impact” on water circulation.