Flood waters accumulated from the catchment areas of Pembroke itself and Madliena have plagued lower Pembroke ever since the inception of the new housing estate in Pembroke. The Marine & Storm water Unit undertook a study to establish the volume of rain water run-off that ultimately passes through Pembroke.

It became apparent that Manche Street and Sisner Street were the focal point of the flooding that resulted from heavy storms. The fact that most of these premises have basements further aggravates the residents’ problem.

It transpires that a water course used to exist in this very same area which crossed the lower end of Sisner Street into the existing valley that lies across Mediterranean Street. In actual fact lower Pembroke was the head of the valley.

Wide water drains once connected to this small watercourse from the locality where the newly constructed primary school is now sited. This water drain in turn was connected to other constructed water culverts which collected the accumulated surface rain water from upper Pembroke.

As development in the Pembroke and Madliena localities increased, more rural land (which helps to absorb much of the water from the rain) was lost and the volume of rain surface water from the roofs of new residential areas augmented to such an extent that any kind of precipitation resulted in flooding.

The catchment area of both localities adds up to 621,849m2 with a resulting surface run-off of 0.43 m3/sec. The proposal for the relief of flooding for lower Pembroke consisted of :

i) Collecting the Madiena surface run-off at Sir Adrian Dingli Street;
ii) Constructing a storm water system in lower Pembroke to cater for both Pembroke itself and Madliena. This would ensure a good safety factor for the probability that urban spaces would increase over the years and also as a back-up in case that not all the surface water from Madliena, is effectively directed away from the residential part of Pembroke.

A catchment pit was constructed at the Sir Adrian Dingli – St Andrews’ road junction. This pit serves to collect the surface water run-off from Madliena and direct it away from the residential part of Pembroke. Thus this would effectively reduce the total volume of water by half. It is proposed that in the near future, the catchment will be augmented to improve its efficiency in collecting the surface water run-off.

A storm water system was installed for lower Pembroke with catchment pits constructed at key positions in Sciberras street, Manche Street and Sisner Street  to collect most of the surface water that gathers in lower Pembroke. The storm water exit is directed from Sisner Street across Mediterranean Street and into an existing water retention (soak away) at the head of the remaining part of the valley. A weir exists further down the water course which also served in the past to connect the shooting ranges which border this part of the coastline.