The National Water Carrier of Israel (, HaMovil HaArtzi) is the largest water project in Israel, completed in 1964. Its main purpose is to transfer water from the Sea of Galilee in the north of the country to the highly populated center and arid south and to enable efficient use of water and regulation of the water supply in the country. Up to of water can flow through the carrier each hour, totalling 1.7 million cubic meters in a day.
Most of the water works in Israel are integrated with the National Water Carrier, the length of which is about . The carrier consists of a system of giant pipes, open canals, tunnels, reservoirs and large scale pumping stations. Building the carrier was a considerable technical challenge as it traverses a wide variety of terrain and elevations.
History
Planning and construction
While early plans were made before the establishment of the state of Israel, detailed planning began after Israeli independence in 1948. The construction of the project, originally known as the Jordan Valley Unified Water Plan, started in 1953, during the planning phase, long before the detailed final plan was completed in 1956. The project was designed by Tahal and constructed by Mekorot. It was started during the tenure of Prime Minister David Ben-Gurion, and was completed in June 1964 under Prime Minister Levi Eshkol, at a cost of about 420 million Israeli lira (at 1964 values).
Agriculture, drinking water, Jordan's share (1964-1990s) The National Water Carrier was inaugurated in 1964, with 80% of its water being allocated to agriculture and 20% for drinking water. As time passed, increasing amounts were consumed as drinking water, and by the early 1990s, the National Carrier was supplying half of the drinking water in Israel. It was forecast that by the year 2010, 80% of the National Carrier would be directed more at providing drinking water. The reasons for the increased demand for drinking water were twofold. First, Israel saw rapid population growth, primarily in the center of the country which increased the demand for water. As the standard of living in the country rose, there was increased domestic water use. As a result of the 1994 Israel-Jordan Treaty of Peace, among other items, Israel agreed to transfer 50 million cubic metres of water annually to Jordan.
Since 2015 (after large-scale desalination) As of 2016, water from the Sea of Galilee was supplying approximately 10% of Israel's drinking water needs. In the previous years, the Israeli government had undertaken extensive investments in water reclamation and desalination infrastructure in the country, while promoting water conservation. This has lessened the country's reliance on the National Water Carrier and has allowed it to significantly reduce the amount of water pumped from the Sea of Galilee in an effort to restore and improve the lake's ecological environment, especially in face of severe droughts affecting the lake's intake basin in previous years. It was expected that in 2016 only about of water would be drawn from the lake for Israeli domestic water consumption, down from more than pumped annually a decade earlier.
Route
Water first enters the National Water Carrier through a several hundred meter long pipeline which is submerged under the northern part of Sea of Galilee. The water passes into a reservoir on the shore and then travels to a pumping station (initially called "Eshed Kinrot" or "Eshed Kinnarot", later renamed "Sapir" after Pinhas Sapir, co-founder of Mekorot in 1937
The pipeline is composed of nine pipes which are joined by an internal cable threaded through them. Each of these pipes includes twelve concrete pipes, each five meters long and three meters wide. As these pipes were cast, they were encased in steel pipes, sealed at the ends and floated out onto the lake. A winged star-shaped cap is mounted in a vertical section of the underwater pipe to allow water to be taken in from all directions.
Water travels to the Sapir Pumping Station on the shore of the lake where four horizontal pumps lift the water into three pipes which subsequently join to form the pressure pipe, a long pressure-resistant steel pipe, which raises the water from -213 meters below sea level to +44 meters. From here, the water flows into the Jordan Canal, an open canal. This runs along a mountainside for most of its route. When full, the water in the canal is deep and flows purely by gravity apart from where two deep wadis intersect the course of the canal (Nahal Amud and Nahal Tzalmon). To overcome these obstacles, water is carried through inverted siphons.