Factors such as rising temperatures and increased volume of rainfall
over short periods of time lead to significant soil erosion and
increased water runoff, which causes sediment and silt to accumulate
inside dams, thus occupying vital water storage space.
The quickest solution adopted by Jordan's Ministry of Water was to
build smaller dams to trap the sediments. But according to Dr.
Salameh, the responsibility must also be shared by the Ministries of
Water and Irrigation, Environment, Municipalities and Works, and the
Secretariat, which imposes on the Kingdom of Jordan to move in
parallel, to adapt its economic, social and other sectors to these
accelerated changes.
This crisis is confirmed by the Secretary-General of the Jordan
Valley Authority, Engineer Hisham al-Haysa, noting that the Kingdom
is affected by climate change, and suffering from it, as its effects
in Jordan have led to the creation of natural phenomena that did not
exit previously.
But does this mean that the authorities should stand helpless?
“Of course not,” he says: “In Jordan, dams with their design
capacity and age are still within international limits, but we don't
want them to increase.”
Dr. Elias Salameh, a professor of water sciences at the University
of Jordan, says that all dam tributary areas face the issue of
sediment deposits in the dams, although there are measures in place
to reduce their impact.
Dangerous forms of climate change
Climate change has doubled the threat to dams, posing a threat to
human sustainable living and stability as well as to the
environment.
According to Dr. Jaafar Wadian, director of the Environment and
Climate Change Directorate at the National Center for Agricultural
Research, local studies in Jordan do not go in parallel with these
changes, including what dams are exposed to.
He adds: “We need more studies to find solutions and recommendations
to lessen the risks.”
What should Jordan do?
The Secretary General of the Jordan Valley Authority, Engineer
Hisham al-Haysa, says that the Ministry of Water and Irrigation has
already started implementing some projects to reduce evaporation
from the dams, as well as studying the condition of the feeder
basins of the King Talal Dam, to find appropriate solutions to
minimize soil erosion through planting of trees and building some
berms in the main valleys.
He added that the Ministry of Water is also conducting a study on
the feeder basins of the King Talal Dam to address the issue of soil
erosion and the impact of sedimentation in the dams, noting that the
preliminary results of this study have shown, that until now, there
is an increase in soil erosion caused by climate change, and a
change in the environment suitable for the indigenous plants to
grow.
The Ministry of Water had launched several initiatives namely the
Water Sector Strategy of 2023-2040, and the Jordan Valley Authority
Strategy 2024-2026, which aim to create an executive action plan
that help enhance water security, and provide farmers in the Jordan
Valley with sufficient water to achieve food security, in addition
to developing existing resources, to help reduce water losses,
increase the efficiency of the sector, and improve its risk
management tools to deal with the effects of climate change.
A destructive type: Amman- Al-Zarqa Basin
Previous studies have revealed the presence of soil erosion and
sedimentation of the destructive type over an area extending to 95
square kilometers of the Amman- Al-Zarqa Basin.
Those studies aimed to assess the risk of soil erosion, and showed
that a total of 350 sq/km are exposed to high-risk erosion, which
affect the basin substantially.
The same studies called for direct measures to be implemented, such
as supporting vegetation cover, managing agricultural slopes, as
well as establishing a monitoring system to combat soil erosion.
This was not the only cautionary study. A World Bank study also
revealed something more serious.
The Soil Erosion Study (prepared by the Jordanian Ministry of Water)
in the Middle Hassa Valley/Tafilah basin, measured the amount of
soil loss to dispersion and the amount of soil transported by rain
water runoff; and it revealed that the amount of soil dispersed by
wind and storms to be 0.53 tons/dunum per year.
The study explained that that damage was due to hight of the slopes,
the soil fragility, and the frequent landslides that took place.
The head of the Directorate of Environment and Climate Change, Dr.
Jaafar Wadian, gives as an example what happen in the largest basin
in Jordan, the Al-Azraq Basin, which collects rainwater in the
eastern region and drains it into more than 15 valleys.
Wadian adds: “When it rains, water get concentrated in one point
known as the basin, as dams are built inside the basins.”
He points to the lack of sufficient water harvesting techniques to
preserve the soil; he explained that these techniques could be put
in place by erecting retaining walls that increase the soil's
ability to absorb water and resist erosion, in addition to planting
forests and increasing the percentage of vegetation cover in the
land as a mean to rehabilitate water basins.
Another example is the Zaghlab Valley basin, which feeds the Zaghlab
Valley Dam in the Koura district in Irbid governorate, where it has
been noticed that the amount of sediment accumulated in the
reservoir has reached 1.62 million cubic meters, and the dam's
storage capacity suffered a rate reduction of no less that 46,000
cubic meters per year, according to a study conducted in 2002.
Dr. Wadian explains that the dam's current condition reveals that
“Its storage capacity has become only half or less of what it was
before, which necessitates addressing the deterioration, as soil is
valuable like time, it goes and does not come back.”
