Shimon Shitrit – Water Supply Engineer
The agricultural water supply for the mid-Arava and Kikar Sdom region is based on brackish water from local well sites. Drinking water is supplied to this region via small desalination facilities. The water supply system in the mid-Arava region is completely independent. It utilizes over 50 well sites to different aquifers and is completely disconnected from nearby systems. In order to support the growing agricultural sector in this region and to improve the quality of water, a master plan has been drafted to supply water to the region. The plan was approved by the Water Authority in 2012.
According to the program, agriculture in the Arava will receive a mixture of brackish and fresh water. As there is no natural fresh water in the region, the increased water supply to the Mid Arava will be based primarily on importing 13 million cubic meters per year of fresh water from the southern Arava region and 8 million cubic meters of water per year from the national water system. In addition, a proposal was made to establish a desalination plant near Neot Hakikar to treat water from local well sites. In order to transport water from the southern Arava, a proposal was made to lay a pipeline that is 28″ in diameter and 35 km long, from Kibutz Yahel to the Paran reservoir near the Paran village. In order to transport water from the national system, a proposal was made to use the Zafit-Sdom line which connects the pools in Zafit, located near the Rotem Plateau, to the southern Dead Sea region.
Due to the long period of time required to implement the master plan and the growing water crisis in the Arava region, Mekorot prepared a general plan for the immediate supply of water to the mid-Arava and Kikar Sdom. This plan includes inspecting several engineering facilities that are needed in order to meet the water needs of this part of the Arava until 2020. The plan included proposals to build new well sites, lay water pipes, and build pumping stations and reservoirs. In addition, the possibility of connecting the mid and southern Arava regions and transferring brackish water from the southern Arava is being considered.
An in-depth assessment showed that water consumption in the southern Arava is primarily during daytime hours. Therefore, due to the limited reserves, some well sites do not operate at night. On the other hand, water consumption is consistent around the clock in the mid-Arava. There are two water reservoirs in the mid-Arava: Shizaf which holds 180 thousand cubic meters, located near Ein Yahav; and Paran reservoir which holds 215 thousand cubic meters, located near Paran. According to water balances, up to 3 million cubic meters of brackish water per year can be supplied to the mid-Arava.
Based on this data, a decision was made to lay a line that will connect the southern and mid Arava regions, called the Arava connection line. Despite the relatively small amount of water than can be transferred from one part of the Arava to the other, the diameter of the line will be 28″, as required for the master plan for the mid-Arava, instead of calculating the diameter of the line according to engineering criteria for the quantities of water to be transferred, due to the challenges of laying the line in this region.
Due to the complexity of this project, the line was divided into three segments, each 10-15 km long. Work on the high-level design for this project continued for 18 months. It was managed by the southern district of Mekorot and implemented by EMS Mekorot Projects, a subsidiary of Mekorot. All stages of the project were coordinated with infrastructure authorities and the Ministry of Defense, as well as with engineering experts at Mekorot and the project designer, who resolved problems that arose over the course of implementation.
The Arava connection line was connected to the Paran-Eilat line which transfers brackish water from bottleneck Paran well sites (located near the point where Route 40 crosses Nahal Paran) to the southern Arava. As the Paran-Eilat line is connected to Eilat via the southern Arava and the water transferred is used as raw water for the Shizafon desalination plant, a hydraulic device with a remote command and control system has been installed on the connection between the two lines so that in case of a malfunction, water transfer can be stopped remotely.
The Arava connection line was connected to the Paran reservoir via a system of special hydraulic devices that address throughput issues and differences in pressure between the line and the reservoir by reducing pressure from 20 atm. to only several meters. These devices are controlled by a regional automatic command system that opens and closes the devices and determines the quantity of water to be transferred based on the levels of the operational pools.
The line had become operable in July 2016. This is a first and important step towards implementing the master plan for the mid-Arava region and towards increasing the water supply to the mid-Arava, even minimally.