Glossary

above ground and underground headraces: pipes (if above ground) and/or tunnels, generally lined with concrete (if underground), that carry water from the reservoir (dam) to the penstocks.

ballast: crushed rocky material forming the foundations to support tracks and for their alignment and levelling.

business plan: annual economic planning document

cagr: compounded Average Growth Rate

claim: claims which may be submitted by the Company to the client commissioning the works in order to obtain additional payments, refunds or compensation – in addition to the sums received and recorded by the counterparty administration – should the Company incur greater unforeseen expenses while performing the works that can be directly and/or indirectly attributed to the client.

cyclopean concrete: concrete for dams characterised by a low cement content and large-size stones

diversion and intake works: works forming part of the hydroelectric complex needed for water flow and electric power production.

earthworks and retaining works: excavation and earth and rock movement works.

gravity dam: a type of concrete dam whose characteristic is its considerable thickness for which the dam itself is responsible for resisting water pressure.

hydro-shield: a technique used for excavation of soft soil (clay, silt, sand) and in the presence of water using TBMs.

penstocks : steel pipes made of considerably thick welded sheet metal that carry water (with a difference in level known as a head) to the power station.

RCC (Roller Compacted Concrete): the technique consists in continuous spreading of concrete with a extremely low water and cement content that is subsequently compacted like any standard road embankment soil. Said technique makes it possible to drastically reduce construction costs and timeframes compared to traditional laying of conventional concrete.

reserves : claims which may be submitted by the Company to the client commissioning the works in order to obtain additional payments, refunds or compensation – in addition to the sums received and recorded by the counterparty administration – should the Company incur greater unforeseen expenses while performing the works that can be directly and/or indirectly attributed to the client.

spillways : concrete works forming part of a dam. In the event of an “overflow” of the reservoir caused by heavy rain and/or reduced use of water for energy production, they make it possible to “spill water away” across the surface of the dam without causing it any damage.

surge tanks: works generally performed underground or as part of hydroelectric plants, needed to regulate water flow (when valves are closed/opened) to avoid overpressure (so-called water hammer) which could cause damage to the penstocks and machinery.

TBM (Tunnel Boring Machine): A modern system for excavation and lining using precast concrete, where required, performed using a complex machine whose main part is a cutterhead equipped with cutters (for hard rock or soft soil). There are various types of TBMs: “open”, i.e. without protection for excavation of hard rock; “shielded” for excavation of soft and/or unstable soil; hydro-shield and EPB (Earth Pressure Balance) for excavation of special, variable soil and/or in the presence of water.

underground hydroelectric plant: electric power production plant which, unlike plants above ground level, is built completely underground, in high-resistance rock formations.