As main aquifers near their red line, the amount of water in the streams feeding the Jordan River continues to drop
Zafrir Rinat | Sep. 4, 2018 | 2:26 AM | 1
Israel’s main aquifers are nearing their red lines, or are even below them now, as the end of the summer approaches. At the same time, the amount of water flowing in the streams feeding the Jordan River is continuing to drop, says the monthly report on Israel’s water sources issued by the Hydrological Service in the Water Authority.
Israel’s two large groundwater reservoirs are the Coastal Aquifer and the Mountain Aquifer. Measurements of the water levels in both aquifers carried out on September 1 show that the Mountain Aquifer is only two centimeters above its red line in the south, and four centimeters above it in the center. If the groundwater level falls below the red line, there is a risk of saltier water penetrating into the aquifer from deeper geological levels. This will reduce the water quality and could make the aquifer unfit for drinking or for agriculture use.
Part of the southern section of the Coastal Aquifer is already below its red line. This part is considered to be a future water reserve and this is particularly dangerous because seawater can now seep into the depleted freshwater.
The groundwater basin under the Tel Aviv area, which is part of the Coastal Aquifer, has been observed to be sinking – relative to neighboring regions. The reason for the formation of this depression is widespread construction, including the work on the light rail project. As part of this digging, it is necessary to pump out groundwater to build the tunnels. The existence of the hydrological depression creates a risk that polluted water will enter the groundwater from nearby areas with a higher water table.
The Western Galilee has another aquifer that is important for supplying water to the region. The levels in this basin rose during the winter because of a relatively large amount of rain. But over the past few weeks, the groundwater levels have fallen below the red line here, too. After a few months in which natural water flowed from the springs in the nature reserve in the area of Nahal Na’aman, the water has since stopped flowing and the reserve is now being supplied with water from a well that has been drilled in the area.
Last month, the amount of water in the streams that feed the Jordan River fell again. The flow measured at the Dan Springs at the very northern tip of Israel was 3.12 cubic meters per second, compared to the multi-year average of 7.2 cubic meters this time of the year. The flow of water measured at the Banias stream was 0.43 cubic meters per second, compared to an average of 1 cubic meter per second this time of year.
The water level in the Sea of Galilee continued to drop and fell by 27 centimeters in August. On September 1, the level of the lake was 1.22 meters below its lower red line. At the same time, the salinity level of the lake continued to rise because as the volume of water drops, the amount of salt remains the same and as a result the salinity rises.
Over the past four years, the salt concentration in the Sea of Galilee has risen by 17 percent, a result of consecutive years of drought. The increasing salinity could make it more difficult to use the lake as a source of irrigation and drinking water.
https://www.haaretz.com/israel-news/israel-s-groundwater-levels-dropping-to-dangerous-lows-1.6445364