Water Transmission Tunnel Delivering the Surplus of the Gelas River to the Lake Urmia Basin Project name: Water Transmission Tunnel Delivering the Surplus of the Gelas River to the Lake Urmia Basin Status Completed Registration Date 2018/09/30 Update Date 2024/07/07 Manager Iran Water and Power Resources Development Co. Goals Transmission of the surplus water resources in excess of demands (irrigation, drinking, and industrial water) from Gelas River basin to Lake Urmia; Controlling and regulating water outflow from the Gelas River basin leaving the country; Controlling and compensating of a portion of water collected from Lake Urmia; Schedule Site and Supreme Supervision (3rd Phase) Executive Actions Excavating a 1354 m access tunnel with a negative 10.2% slope; Excavating a 135-m-long, 15-m-high, and 15-m-wide cavern for disassembling the Tunnel Boring Machine (TBM) inside a granite rock mass; Excavating the first segment—the alluvial part—of the main tunnel with a length of 15 km and a negative slope by a Dual Mode TBM from the entrance portal to the cavern where the TBM was disassembled; Assembly of the TBM DS at the exit shop; Excavation of the second segment, with a length of 20.2 km, by a TBM DS at a positive slope; Water transfer capacity of the Gelas Tunnel: 646 million cu. m per year. Geography Location Naghadeh, Piranshahr, Southern West Azerbaijan Province, Iran