Permeability studies of the limestone reservoir of Atrozela dam (Cascais)

Abstract

With a view to increasing the water supply capacity at the terminal section of the distribution lines, EPAL, the public company in charge of the water supply to Lisbon and surrounding districts, considered the possibility of creating a storage reservoir by the construction of a dam, about 20 m high, on the Penha Longa River near Cascais.

The reservoir to be created by this dam is approximately 2km long, with a storage volume of 1,5 x 106 m3 and is, in its entire extent, situated in a limestone mass with interbedded marl layers.

ln order to define the feasibility of the undertaking, a study of the permeability characteristics of the rock mass was carried out, this study including the project for the works required to ensure the watertightness of the reservoir.