L’acquedotto dell’imperatore Traiano per il porto di Centumcellae, oggi Civitavecchia, nel contesto ambientale dei Monti della Tolfa, Italia centrale
Author(s)
Date Issued
2023
Type
article
Volume
1
Start Page
41
End Page
73
Journal
Abstract
The aqueduct built by Traiano for the port of Centumcellae in 102 – 110 A.D., 35.5 km long, is located in the Tolfa Mountains with hilly morphology and made up largely of the clayey-calcareous Tolfa Flysch (upper Cretaceous-Eocene) and lava rich in silica of the Allumiere Unit (upper Pliocene–lower Pleistocene), subordinately the Torrent of San Savino Unit clays (Zanclean). The Lava complex is an aquifer supported by the Flysch and Clay complexes
with degree of relative permeability from very low to zero, vertically and laterally divided into compartments characterized by medium high to low degree of relative permeability, separated by an indefinite permeability limit, and perched water bodies at different altitudes of limited extension, that emerge in minor springs with a yield < 1 l/s and major ones with a yield > 5 l/s. The major springs Cinque Bottini and Trinità were captured by the Roman technicians through the drainage tunnels. ACEA Ato 2, that manages the two springs, did not allow access to check the yield, temperature, and chemical physical parameters of the water. Therefore, the literature indicates that in 1693 the yield decreased from 17.5 in April to 9.5 l/s in August, in 1742 and 1761 it shows values between 11.25 and 13-15 l/s, and in 1953 it reaches its lowest value (7.5 l/s). The investigation of the first 6 km of aqueduct shows that the canal built in concrete has an average slope of 0.44%. The terminal cistern of aqueduct, buried about 800 m upstream of the port of Centumcellae, includes two rooms lined with hydraulic mortar and communicating by means of a lead pipe. Each room has a net volume of 593.9 m3: one with the function of a piscina limaria (“b”), the other as a reservoir (“a”). The aqueduct, subjected to substantial restoration work by Pope Innocenzo XII in 1756-1758, operated until the end of the 1950s.
with degree of relative permeability from very low to zero, vertically and laterally divided into compartments characterized by medium high to low degree of relative permeability, separated by an indefinite permeability limit, and perched water bodies at different altitudes of limited extension, that emerge in minor springs with a yield < 1 l/s and major ones with a yield > 5 l/s. The major springs Cinque Bottini and Trinità were captured by the Roman technicians through the drainage tunnels. ACEA Ato 2, that manages the two springs, did not allow access to check the yield, temperature, and chemical physical parameters of the water. Therefore, the literature indicates that in 1693 the yield decreased from 17.5 in April to 9.5 l/s in August, in 1742 and 1761 it shows values between 11.25 and 13-15 l/s, and in 1953 it reaches its lowest value (7.5 l/s). The investigation of the first 6 km of aqueduct shows that the canal built in concrete has an average slope of 0.44%. The terminal cistern of aqueduct, buried about 800 m upstream of the port of Centumcellae, includes two rooms lined with hydraulic mortar and communicating by means of a lead pipe. Each room has a net volume of 593.9 m3: one with the function of a piscina limaria (“b”), the other as a reservoir (“a”). The aqueduct, subjected to substantial restoration work by Pope Innocenzo XII in 1756-1758, operated until the end of the 1950s.