The network of transporting 1.7 billion liters of water across the desert

When Israel was founded in 1948, the country faced a big problem. How to provide enough water for the population to increase rapidly on the mainland when the natural rainfall is unevenly distributed? The national water guide system (NWC) was born from this challenge. This is a technical project designed to transport large amounts of water from wet North to the Central and the South. Both technically both technically and play a key role in the development of the whole country, NWC contributes to Israeli’s geographical reshao, consolidating the economy but also has a lot of controversy, according to Interesting Engineering.

In the late 1940s, Israel recorded the number of new residents soared as a result of World War II. In 1948, the population in the region was only over 800,000. Only 3 years later, in 1951, the population doubled to 1.6 million. Today, that figure has exceeded 9 million people, all concentrated in the area of ​​about 22,000 km2, equivalent to the area of ​​New Jersey state of the US.

The rapid increase in the population revealed an important challenge that the water scarcity due to uneven rainwater distribution. The northern region is like the Galilee Sea and the Jordan River basin with abundant rainfall, an average of about 102 cm of rainwater per year. However, most of the residents have settled in central and southern Israel, the area has much lower rainfall. The vast Negev desert accounts for about half of the country’s total land area, with some points that receive less than 10 cm of rainwater every year.

While the Bedouin community has long been adapted to the harsh conditions of Negev, the new population requires more reliable remote water. Ensuring the essential water access to meet the demand of the booming population and laying the foundation for the future development of the country.

The platform of the water system

Born in the early 1950s, Israel’s National Water System (NWC) was designed to solve uneven distribution of water distribution. Stretching 130 km, the system consists of a series of works below and above the ground, 87 km of steel pipes and concrete, 13 km of dug tunnel through rough stone and 8 km of open -up canal connected with Large reservoirs.

The construction process began in 1958 under the direction of Tahal, a water resource planning company, and completed after only 8 years, in 1964. The original system transported 450 million m3 of water every year, the level The peak is 1.5 million m3 of water a day. The cost of 420 million USD of the project is equivalent to 4 billion USD today.

It is important that the project is built to meet the future development. The engineers design modules in water management technology to increase capacity when the population expands. Today, the system can transport water nearly 4 times the initial capacity, leading 1.7 billion m3 of water through the annual network.

Overcoming the challenge of height

A clear technical task for NWC is to transport water to the high hill from the Galilee Sea located at 213 m below the sea level, across the total difference of about 600 m. The journey starts from the Sapir pumping station, pushing the water to 250 m high from the main starting point of the network. Next, the Tzalmon pumping station uses turbines and separate pumps to lift millions of m3 to 115 higher in the first steep part of the roadmap.

From Tzalmon, the water flow into the Yakov tunnel, a 850 -meter -long path under the hills in Elun. Digging through limestone and basalt stone is a challenge for thousands of workers, engineers and experts when they have to maintain the ideal slope for gravity -based motion, and at the same time at least need to use additional machines. pump. Reinforcing 3 m wide tunnels of steel and concrete helps ensure the work withstand high water pressure, allows expanding capacity in the future. In addition to this underground wonder, two other large pumping stations in Eshkol and Mishmar Haemek also helped coordinate, filter and balance the water before bringing water to Negev in southern Israel.

Minimize loss due to evaporation

Because most of Israel has only a minimum rainfall and high temperatures, the evaporation phenomenon is a worrying issue, especially for reservoirs on the ground and Dao Lo Canal. To solve the problem, engineers apply some measures. Many smaller reservoirs are built in an oval or circular shape to reduce the exposed surface area, thereby reducing the volume of water loss due to evaporation. Eshkol Reservoir, one of the largest lakes in the network, can accommodate more than 5 million cubic meters of water. The lake is 400 m wide and 15 m deep, carefully built to prevent evaporation through reducing the surface in contact with the wind and sunlight.

The canal design is in the same direction. They usually have a trapezoid with diverse depth and slope to limit heat absorption in the exposed area. By taking advantage of the basic principles in physics and hydrology, the group of engineers behind NWC ensures every paragraph from pipes and tunnels to the reservoir and canal are kept as long as possible water resources price.

Desert transformation

The huge success of NWC shaped the urban landscape of Israel, especially the Negev desert. Towns such as Be’er Sheva transformed into a prosperous education, research and industry, directly benefiting from stable water supply. ARAD, the first Israeli plan, established in 1962, also developed despite the harsh desert environment thanks to a stable water supply from NWC. Other areas such as Dimona, Mitzpe Ramon, and Kiryat GAT also grew rapidly, which is impossible if there is no sustainable and accessible water infrastructure.

Controversy and technical solutions

Despite the achievements, NWC still causes concern in the international arena. Jordan, Syria, and Lebanon countries are afraid of excessive water exploitation from the Galilee Sea will lower the amount of water in the Jordan river basin. In the late 1960s, that fear became a reality. Environmental organizations also criticized the project to destroy the flora and animal dynamics and the quality of local water, especially along the downstream of the Jordan River.

A major change took place with the appearance of deal technology, first tested in Israel in the 1960s for industrial purposes. Through reverse osmosis, seawater is pushed under high pressure through semi -absorbent membranes to separate salt and impurities from drinking water. In the early 2000s, Israel invested heavily in this technology, building many deal plants along the Mediterranean coastal area. Today, these facilities account for 70-80% of domestic water supply and coordinate with NWC infrastructure to distribute across the country. This combination helps reduce concerns about over -use of freshwater resources.