The Maltese islands have very few permanent freshwater streams.

Found on the west side of Malta and in Gozo, these streams are an important habitat to a number of species and plants.

These streams occur in places where the clay layer is still intact.

The Maltese islands are made up of five layers of sedimentary rocks. Rainwater can percolate through all these layers except clay.

In areas where no clay is present, rainwater percolates through the rock strata until it reaches sea level and forms a layer on top of the salty water.

This is the water that is extracted through boreholes and galleries for domestic and commercial use. On the other hand, percolating water does not pass through areas with a layer of clay. The water on top of the clay moves horizontally until it finds a way out, usually a fissure in the rocks and thus forms a stream.

At Baħrija valley we find one of the most important freshwater streams in the Maltese islands.

It provides the habitat for the rare freshwater crab known in Maltese as qabru, a species that requires water to survive all year round.

The conservation of this particular species is of utmost importance because the local race is endemic to the Maltese islands, that is, it is not found anywhere else in the world.

The freshwater crab is already legally protected and nobody can pick it up or kill it but what is required is more protection of its habitat.

The water must be allowed to flow and any form of pollution, especially through pesticides and herbicides, should be strictly controlled.

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