GROUNDWATER LEVEL AND SALINITY
IN THE MOUNTAIN AND COASTAL AQUIFERS
1. SALINITY OF GROUNDWATER
IN THE MOUNTAIN AND COASTAL AQUIFERS
1970–2009
Milligrams of chloride per liter
275
Maximum recommended concentration in drinking water(1)
250
225
200
175
150
125
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
100
Coastal Aquifer
Mountain Aquifer
(1)
According to “The Nation’s Health Regulations (Sanitation Quality of Drinking Water), 1974 [Integrated Version –
2000]”: Maximum recommended concentration in drinking w ater – 250 milligrams of chloride per liter; maximum permitted
concentration in drinking w ater – 600 milligrams of chloride per liter.
2. GROUNDWATER LEVEL IN THE MOUNTAIN AND COASTAL AQUIFERS
1970–2009
20
15
10
5
0
-5
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Level relative to sea level (meters)
25
Coastal Aquifer
( 35 )
Mountain Aquifer
Description of the indicator
The indicator presents data on chloride concentration and the level of groundwater in the two
main aquifers in Israel. These data are useful for the investigation of groundwater quality.
Relevance of the indicator to sustainable development
An increase in the salinity of groundwater can influence the environment, society, and the
economy in multiple ways, such as: impairment of the quality of drinking water and that of
water used for irrigation; salination of soil, which harms agricultural crops; creation of a future
need to invest in advanced treatment methods or desalination; reduction in the ability to
pump; and limitation of the water sector's ability to handle future crises. Groundwater level
and salinity indicators are central to the determination of the quality of drinking water
abstracted from various sources. Groundwater provides between 60% and 70% of annual
water consumption in Israel. In the future, the proportion of groundwater out of total water
consumption in Israel might change due to increased usage of desalinated sea water.
Nevertheless, groundwater will likely continue to be an important source of water in Israel.
Most of the groundwater is abstracted from two main aquifers: the Mountain Aquifer and the
Coastal Aquifer. Ongoing monitoring of the quality and availability of groundwater is essential
for the continued existence of these reservoirs as sustainable sources of water.
Selected findings

The average salinity in the Coastal Aquifer continues to rise. In 2009 the average chloride
concentration in drills in the Coastal Aquifer reached 219 mg/l chloride (milligrams of
chloride per 1 liter of water).

Over the past forty years, the chloride concentration in the Coastal Aquifer has increased
by an average of approximately 2.3 mg/l chloride per year.

The increase in salinity of the Coastal Aquifer is affected by over-pumping, which causes
a drop in water levels and the ingress of sea water. It is also affected by droughts,
irrigation, and the ingress of effluents and water from the National Water Carrier.

In the hydrological year 2007/08 (from October 2007 to September 2008), 36.5% of the
volume of water pumped from the Coastal Aquifer was of good quality (up to 250 mg/l
chloride and less than 45 mg/l nitrates), 44% was of satisfactory quality (up to 400 mg/l
chloride and less than 70 mg/l nitrates), and 11% was of poor quality (over 400 mg/l
chloride or at least 70 mg/l nitrates). The quality of the remainder was unclassified.
According to data from the Hydrological Service, approximately 48,000 tons of chloride
were added to the Coastal Aquifer during that year, primarily the result of human activity
(38% from irrigation and 30% from the Dan Region Reclamation Project).
( 36 )

In 2009, the average chloride concentration in the Mountain Aquifer drillings reached 143
mg/l chloride, similar to the average concentration in 2008.

According to data from the Hydrological Service, in the hydrological year 2007/08,
approximately 85% of the water pumped from the Mountain Aquifer had a salinity level of
less than 300 mg/l chloride. In 87% of the drillings, no trend of change in salinity could be
identified. In 11% of the drillings, an increase in chloride concentration was observed,
and in 2%, a decrease was observed.
( 37 )