The Dahla Dam, also known as Arghandab Dam and Kasa, is located in the
Shah Wali Kot District
Shah Wali Kot District ( ps, شاه ولي کوټ ولسوالۍ, fa, ولسوالی شاه ولی کوت) is situated in the northern part of Kandahar Province, Afghanistan. It borders Khakrez District to the west, Naish District and Oruzga ...
of
Kandahar Province
Kandahār ( ps, ; Kandahār, prs, ; ''Qandahār'') is one of the thirty-four provinces of Afghanistan, located in the southern part of the country, sharing a border with Pakistan, to the south. It is surrounded by Helmand in the west, Uruzga ...
in
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is borde ...
, approximately north of the provincial capital
Kandahar
Kandahar (; Kandahār, , Qandahār) is a city in Afghanistan, located in the south of the country on the Arghandab River, at an elevation of . It is Afghanistan's second largest city after Kabul, with a population of about 614,118. It is the c ...
. Constructed in 1952, it is said to be the second largest dam in Afghanistan. As of 2019, the Afghan government is spending $450 million on making the dam more useful. The project includes raising the dam's walls by 12 meters so its
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contr ...
can hold nearly a billion cubic meters of
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does incl ...
and installing three turbines for the production of 22
megawatts
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wat ...
(MW) of electricity.
The Dahla Dam is built on the
Arghandab River
Arghandab is a river in Afghanistan, about in length. It rises in Ghazni Province, west of the city of Ghazni, and flows southwest passing near the city of Kandahar, and then joins the Helmand River below Grishk. In its lower course, it is mu ...
which flows over a length of . Over the years its reservoir was subject to
siltation
Siltation, is water pollution caused by particulate Terrestrial ecoregion, terrestrial Clastic rock, clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the ...
, and its canal system reduced irrigation benefits. This necessitated undertaking rehabilitation of the dam which involved desiltation works and pertinent components of the project to improve the water delivery system; this component was completed during March 2012 with assistance provided by
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...
. The second phase involved raising the height of the dam and the relevant dykes to compensate for the loss of storage in its reservoir due to siltation, and to achieve the full benefits of irrigation for which the dam was originally built.
History
The Dahla Dam was originally built between 1950 and 1952 when relations between Afghanistan and the United States were beginning to quickly develop. The purpose of the dam was to help farmers in Kandahar Province and provide clean drinking water to the city of Kandahar.
The Dahla Dam is an embankment structure made of earth and rock fill. It is in height. The length of the dam at the crest is about . In the periphery of the dam six saddle dams have been built which together measure and with varying heights of . To pass the design flood discharge two spillway structures have been built. To release water for irrigation to the canal system low level sluices have been built at the downstream toe of the dam with two control valves of the Howell-Bunger type which function as energy dissipation bypass valves.
The reservoir created by the dam has a storage capacity of 314 MCM. The irrigation system designed to provide irrigation to of land in the Kandahar province consisted of of the main canal and of branch canals; with the main canal designed to carry a discharge of per second. The contractor for the project was Morrison-Knudsen Afghanistan Incorporated. The dam and the irrigation system are under the control of the
Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
occupation. A technical appraisal of the status of the project carried out by experts from
Agriculture and Agri-Food Canada
Agriculture and Agri-Food Canada (AAFC; sometimes Ag-Canada; french: Agriculture et Agroalimentaire Canada)''Agriculture and Agri-Food Canada'' is the applied title under the Federal Identity Program; the legal title is Department of Agriculture ...
in 2008 revealed that the siltation in the reservoir had resulted in reduction of the storage capacity by 34%, irrigation system had deteriorated resulting in loss in canal discharge to the extent of 70% on account of siltation, evaporation, seepage and other defects. The intake tower of the dam was not functioning properly and control valves were leaking, spillway capacity to discharge flood waters was inadequate, and there was no operational plan. Even before the rehabilitation of dam and canal system could be initiated, as first priority the mines in the rocky areas of the reservoir area had to be cleared which was done by the
U.S. Army Corps of Engineers
, colors =
, anniversaries = 16 June (Organization Day)
, battles =
, battles_label = Wars
, website =
, commander1 = ...
. After this operation, a two-phase rehabilitation plan was launched.
On completion of the rehabilitation works by raising the height of the dam and related appurtenant works and the improvements of the canal system the volume of available water would be increased from 300 million cubic meters to 484 million cubic meters, which would facilitate irrigation to command areas in the districts of Shah Wali Kot, Arghandab, Zheri, Panjwai, Maiwand, Dand and Daman and also help in planning and building a 10 MW capacity hydropower station to generate electricity.
Phase 1
In the first phase the rehabilitation works were carried out by Canada during the period from 2009 to 2012 under the project titled "Arghandab Irrigation Rehabilitation Project" at a cost of nearly $44 million US dollars. Desilting and repairs to of main canal and about of branch and minor canals, replacement of water valves and erecting gates to improve control over the flow of water supplying to farm fields from the reservoir of the Dahla Dam were carried out.
Phase 2
Raising the height of the dam is seen crucial to increasing the volume of available water, which has reduced to around 290 million cubic meters from about 500 million cubic meters water. The rehabilitation work during this phase involved raising the height of the dam by , of saddle dams by , spillways, and modifying structural, hydraulic and electro-mechanical features. The work was initiated by the
U.S. Army Corps of Engineers
, colors =
, anniversaries = 16 June (Organization Day)
, battles =
, battles_label = Wars
, website =
, commander1 = ...
but then abandoned due to a financial issue with the Afghan government.
Phase 3
The third phase of the project was scheduled to be completed in 2024. In this regard, former deputy Minister of Energy and Water Abdul Basir Azimi stated the following: According to Toryalai Mahboobi, Kandahar basin chief, the reservoir of Dahla Dam would have 950 million cubic meters of
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does incl ...
after the third phase of the project is completed.
See also
*
List of dams and reservoirs in Afghanistan
Dams and reservoirs in Afghanistan are used for irrigation, water supply, hydro-electric power generation or combination of these. Below are a map and a chart showing some of Afghanistan's dams and reservoirs.
Location map of major reservoirs a ...