The proposed operation includes the construction of two new additional external water supply networks in the Municipality of Voio with the aim of improving the water supply status of the settlements of Eratira, Galatini, Mikrokastro and Siatista in the Municipality of Voio, the better management of the water supply of the Eratira Springs and the reduction of energy consumption in the existing pumping stations.The operation will be implemented in five sub-projects.The following interventions are foreseen: Construction of a new supplementary external water supply network with a gravitational pressure pipe 762128m in length Φ250mm in diameter made of 3rd generation PE 100 polyethylene, class 20atm, starting from a new cast well near the Eratira tank and ending at the A2 Kaloneri pumping station where a new connection sharing shaft is constructed in an existing water storage tank level control pipeline Construction of a new supplementary external water supply network with a gravitational pressure pipeline 727163m in length Φ180mm in diameter of polyethylene. PE 3rd generation and class 125atm from the existing tank of Mikrokastro to the existing pumping station of Katseli with simultaneous upgrade of the pumping station with replacement of the existing pumping complexThe operation also includes horizontal auxiliary actions for archaeological research and works as well as Technical Consultant services