G.RE.T.A. INSTALLATIONS FOR REAL-TIME MONITORING OF IRRIGATION DAMS AND CANALS

Climate change, with periods of drought and concentrated periods of intense rainfall, has drawn attention on the importance of retaining and properly managing water for agriculture. More than 50% of water in Italy is addressed to irrigation and 47.9% of the total extracted water does not reach the final user (ISTAT report on water 2015-2018). The construction of new irrigation reservoirs is expected in Italy (PIANO NAZIONALE NEL SETTORE IDRICO – “SEZIONE INVASI” art. 1, 155, 145/2018) and one critical issue is ensuring the integrity of these infrastructures, not only for saving water but also for reducing the hydrogeological risks. G.Re.T.A. (Geoelectrical Resistivimeter for Time lapse Analysis) is an Italian autonomous geo-resistivimeter developed by LSI Lastem with scientific support of Politecnico di Milano. It uses Electrical Resistivity Tomography (ERT) measurements for long-term installations. Since soil resistivity is a function of granulometry, porosity and water saturation, G.Re.T.A. can monitor structures in real-time to identify potential seepages, fractures, and similar heterogeneities that can lead to leakages (loss of water) or collapse (risk for human lives and economic activities). The system works remotely and sends data to a cloud platform, where results can be analyzed. Thresholds of alarm can be set and the instrument can be programmed accordingly. Consorzio di Bonifica di Piacenza has recently included a permanent geoelectrical monitoring system in the technical specifications of a tender for the construction of an irrigation basin that will be built in Fabbiano di Borgonovo. The monitoring system will scan the daily situation of the structure, providing an innovative method to assess the vulnerability of the dam to avoid loss of water and to increase the effectiveness of the distribution network. G.Re.T.A. has been already installed along two levees to monitor possible concentrated seepages and detect animal burrows: an irrigation canal in San Giacomo delle Segnate, and Parma river in Colorno.