Environmental, foundation or concrete chemistry conditions, such as AAR, lead to water infiltration in the dam body, with subsequent cracking, spalling and deterioration of concrete. Over time the infiltration increases: fines and calcite from the concrete are transported and may cause clogging of the drains; water saturates the dam body; undesirable uplift pressures increase and the factor of safety is reduced; productive water is lost and further deterioration is accelerated.

The installation of a synthetic geomembrane on the upstream face, with a drainage system behind, provides the following benefits:

- stops water infiltration, bridges joints and even large cracks

- reduces/prevents the formation of uplift pressures

- provides freeze/thaw protection to the face

- promotes a substantial reduction in water content of the dam body (dehydration)

- may assist in retarding alkali-aggregate reaction (AAR)

- can withstand seismic events, bridging potential openings of cracks and fissures

- minimum surface preparation is required

- can be quickly installed, in the dry and underwater

- has a well documented long durability

- more than 20 years maintenance-free history.

CARPI has lined more than 45 large dams of all types, to a maximum height of 174 m (571 ft). All installations, some of which are more than 25 years old, prove the system's excellent durability, even in the most severe environments, from the Alps to the Equator.