The project for the construction of hydraulic safety works for the Lago della Spina dam, in the municipality of Pralormo, became necessary due to damages wreaked upon the dam following the flood of 1994.

The main works are as follows: refurbishment and re-profiling of the downstream facing of the dam, surface water spillway and bottom outlet, by-pass conduit to convey the water under pressure for irrigation purposes, stilling basin to dissipate the water discharged by the bottom outlet and spillway.

The correct design of the morning glory spillway and the stilling basin located downstream of the discharge was checked on the basis of the results provided by a physical model.

The geotechnical analysis provided the design guidelines for interventions to be carried out on the dam body, in order to guarantee its stability in accordance with the safety coefficients required by current legislation.