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Lake Hamun, a Disaster in the Making
Hydropolitics of Hirmand and Hamun

Pirouz Mojtahed-Zadeh, Ph.D.
University of London


A substantial environmental disaster has been in progress in the eastern parts of Iran in the past ninety years or so. The Hamun,1apparently a much larger lake in the past than it can ever be in a high-water-level year of our time, has gradually diminished and with it almost the whole of the Neyzar (reed forest) and its related economic life, with disastrous environmental consequences for the Sistan province of Iran. Hamun, the only fresh-water lake in Asia, is not only the main source of irrigation in Sistan, but other than river Hirmand, it also provides many water-associated economic activities - hunting in the Neyzar, ferrying goods and passengers across the lake, fishing and reed-associated handicrafts - and has a pivotal role in the living of the population of this southern edge of Central Asia. With the diminishing body of the lake and the Neyzar, all these economic activities are diminishing, while the damage to the agricultural life of the province has forced thousands of the local population to migrate from Sistan to Gorgan and other areas near the borders with Turkmanistan.

The Geographical Setting

The district of Sistan constitutes the middle section of the eastern Iranian borderlands. It is 36,000 in land area with a population of 274,611 and this density of 33.8 per makes Sistan the most populated region in the entire eastern Iranian borderlands.2

Sistan is predominantly a flat land, and is mostly made up of sediments from Hirmand.3The lowest point of the district is Hamun-e Hirmand which drains all water in the region. The surrounding lands have an almost negligible slope towards the lake. The only mountainous part of Sistan is its north-western corner where the Bandan range ends, and its western flanks where the Kuh-e Plangan range represents the highest peak in the region.

Although Sistan geographically is located in the Iranian plateau of Central Asia, most of it falls politically under Afghanistan, with a small portion in Pakistan. Almost the entire area of the Iranian part of Sistan is formed of sediments from river Hirmand, creating one of the most fertile lands in Iran. But utilisation of its fertility cannot be maximised because of water shortage and precipitation. A major climatical feature of the province is a high-velocity northerly wind blowing from the mountains of Afghanistan in the spring and early summer months with a speed of 70 to 100 miles per hour, bringing in hot and dry air mixed with sand. This continues for 110 to 120 days and this wind is locally known as "the wind of 120 days". This wind, together with a high temperature causes intense evaporation of the sheets of water in Sistan.

Having frequently been referred to in the historical documents as the "bread basket" of Khorasan (old Khorasan, now known as Central Asia), Sistan's traditional economic fortune has diminished as a result of the diminishing water supplies from River Hirmand into Lake Hamun. River Hirmand and Lake Hamun are the main geographical features in Sistan.

Lake Hamun

Due to its geographical location, perennial character and its fresh water, Lake Hamun, historically known as "Sea of Zereh", is the most important lake of eastern parts of the Iranian plateau. As a major basin, Hamun collects water from a considerable area - of which about three-quarters comes from Afghanistan - and flood waters from the mountains of its immediate vicinity. This factor together with the lake's shallowness - no more than 10 metres deep at the most4 - and with the minimum slope of the shore-lands and because of the inconstant regimes of the various tributaries, are responsible for the considerable variations in the surface occupied by the lake in the course of the year, as well as from one year to another. The sheet of water at the end of the high-water period (May) of each year can reach an area of about 3,200 while in the dry season the surface area of the lake reduces to a mere 1,200

During the low-water season the lake is divided into, at least, four separate sheets of water locally known as Hamun-e Saberi to the North which is the deepest, Hamun-e Puzak to the north-east and in Afghan territory, Hamun-e Shapour to the South and a central pool known as Hamun-e Hirmand. These separate sheets of Hamun water become one at flood times when the level of the lake rises. The surplus water flows out, at the southern end of the lake, through the channel of Shileh Shallaq into the depression of God-e Zereh inside Afghanistan.6 This annual mechanism has not, however, functioned for several years owing to the diminishing water level of the lake. The rise in the water level of the lake in the very recent years does not represent a change of hydropolitical decision, it is because of lack of control in the war-torn Afghanistan.

Hamun Lake, according to historical documents, covered a much larger area than it may cover in a very high-water year in our time. G.P. Tate described the lake, at the turn of the twentieth century as something like 150,000 square miles.7 The highest water mark which can be traced around Lake Hamun is five feet above the level recorded in 1903 by Colonel McMahon's Arbitration Commission, when the lake established this record.

Hirmand River

There are a number of streams emptying into Lake Hamun of which Hirmand is the only perennial and far more important than all other tributaries put together. Hirmand's delta region is measured as being 150,000 The course of the river upstream of the delta, lies entirely in Afghanistan.

Rising in the mountains of north-west of Kabul, Hirmand flows towards Iranian Sistan, after meandering for about 1050 km in Afghan mountains and plains. Throughout its course in Afghanistan, Hirmand receives from a number of significant tributaries, of which two are most important; Musa Qaleh and Arghandab.8 Having received Arghandab near Bost (or Bist) at the edge of mountain zone, Hirmand crosses the deserts for about 400 km before reaching Chahar-Borjak which is the beginning of Greater Sistan, 70 km. upstream of the Iranian border, where there is a measuring station. Of the water that Hirmand drains and brings in to its delta annually, more than one billion cubic metres. are used for agricultural irrigation in the Sistan of Iran. The utilisation of the accumulated waters, if limited to the middle basin of the river, would have a strong repercussion on the delta region.

In the delta which begins at Kuhak, Hirmand divides into two main branches of Rud-e Sistan and Rud-e Parian, each subdividing into many branches and canals. Data available from Colonel McMahon's Arbitration Commission's measurements of Hirmand water at the turn of the twentieth century indicate annual flows (from October to September) of three years - 1902 to 1905 - respectively of 7.7, 5.4 and 3.6 billion cubic metres; minimum monthly flows of 45-50 million cubic metres; and a maximum of about 2000 million cubic metres.9 Against these figures, data gathered in the period between October 1946 and September 1950 by the Hirmand Delta Mission, shows that the flows were 2.2, 4.5, 6.6 and 6.5 billion cubic metres respectively, with minimum monthly flows in the months of September and October (excluding the exceptionally low September 1947) of 30 x 10 cubic metres. (equal to a capacity of about 11-12 cubic metres. per second) and with a maximum of 1.8 - 2.6 x 10 cubic metres. in the months of April and May (700 - 1000 cm. per second).10

The above two sets of data show a drop in the average amount of water flowing in Hirmand downstream in the first half of the twentieth century during which there was no diversion dam nor a canal constructed in Afghanistan. Hirmand river's average annual debit in the 1990s is estimated at 2 to 3 billion cubic metres. This debit was 6000 cubic metres per second in 1990, and 3000 cubic metres per second in 1993. This figure further reduced to a mere 45 cubic metres. per second in 1994, of which only 15 cubic metres per second entered Iranian Sistan.11

The latest reported flood of major consequence took place in April 1991 after many years of low water and droughts, causing extensive damage in Sistan. This flood was the outcome of a combination of high level snow melting and lack of control in Afghanistan, both administratively and technically, owing to the prevailing political situation in that country.

Evolution of the Water Disputes

Although the actual location of the boundary between Iran and Afghanistan in Sistan has since long been accepted by both sides as being in the middle of Hirmand's main delta branch, disputes concerning allocation and other reparian rights have not as yet been resolved. This in spite of several attempts in the past 120 years to settle these disputes. The original problem was that rulers of the British protectorate of Afghanistan at the turn of the twentieth century considered river Hirmand as an internal river of that country, reserving for Afghanistan the right to utilise its water in whatever way it wished. McMahon's Memorandum of 25 September 1904 asserts:

"The Afghan Government does not admit that there is any water question in dispute, as their geographical position makes them sole owner of the whole Helmand above the Band-i-Sistan".12

By thinking so, not only did the Afghan rulers ignore the rights of the people of downstream Hirmand whose life depended so exclusively on the water supplies from that river, but it also ignored international trends towards recognising the status of rivers passing through more than one country as "international rivers". Prior to this, when the local rulers of Khozeimeh dynasty were in control of affairs and defence of Sistan and eastern Iranian borderlands, regional interests were served effectively and the local inhabitants benefited. But as local advice began to be ignored by the national government, especially from the early years of the twentieth century when administration of affairs of all regions of Iran was put under the control of a centralised authority, national interests of Iran in Sistan were not served well.

The actual problem began when British boundary arbitration officer, General F. Goldsmid decided in 1872 to put the Iran-Afghanistan boundary in Sistan on the main branch of the Hirmand in the delta region without making any arrangement or recommendation for water division between the two sides.13 The only mentioning of Hirmand water made in Goldsmid's boundary award was that:

"It is, moreover, to be well understood that no works are to be carried out on either side calculated to interfere with the requisite supply of water for irrigation on both banks of Hirmand." 14

Further disputes occurred between the two countries, mainly because the river changed its course in the border area in 1896. British arbitration was sought once again and Colonel Henry McMahon was assigned in 1903 to delimit and demarcate new boundaries. McMahon's new boundary was, in practice, the same as previously defined by General Goldsmid, except for the fact that McMahon had made a water award in 1905,15 which created more problems than it was supposed to settle.

Having decided to divide the Hirmand water at the border area, equally between the two sides in 1903-4,16 Colonel McMahon changed his decision in 1905 for reasons unknown and allocated two-third of Hirmand water in the delta to Afghanistan and one-third to Iranian Sistan,17 which is much more fertile and a great deal more populous than the corresponding Afghan border district of Nimrouz. The injustice done to the Iranian Sistan in this water award can be measured by reading McMahon's own comments on the unfairness to Iran of his first award (1903-4) which divided the Hirmand water equally between the two neighbours. On the equal division of Hirmand water Colonel McMahon stated:

"Even an Afghan, however, must acknowledge, when it is brought home to him, as it should be, that any settlement which restricts Persian rights to water to certain limits is in the present case a distinct gain for Afghanistan who has hitherto taken off, only 16/100ths of the whole river from Rudbar downwards, while the Persians have taken 62/100ths. Any deferred settlement of the question might have to recognise the Persian right to what custom may have entitled them to...."18

Having acknowledged the above facts about Iran's rights to the Hirmand water, McMahon allocated two-third of that water to Afghanistan in 1905. The Iranians, however, found McMahon's 1905 water award of one-third to Iran, two-third to Afghanistan unacceptable and refused to ratify it. Local peasantry was so offended by this award that they decided to actively defy its terms. The Afghans, by contrast, were pleased with this water award.19

As the summer months of 1905 drew closer and Hirmand water began to become scarce in Sistan, local Sistanis opened two new canals from the main stream of Hirmand where both sides were debarred by McMahon's water award from cutting off from the river. Since his award had not been accepted by either side at the time, McMahon could not do much about it. The action, however, renewed the disputes between the two sides. Letters of complaint from the Sistan population scorning McMahon and the British for their "conspiracy" against their water rights appeared in the opposition Iranian newspapers abroad and in the Russian newspapers. The Russians wrote letters to the Iranian Crown Prince expressing their displeasure of what the British arbitration did to the water rights of the people of Sistan.20 Local Sistanis attacked and burnt down British arbitration headquarters21 and the Iranian government requested fresh arbitration which never materialised.

The dispute, however, continued for years. In his confidential diary of December 1929, the British Consul of Sistan indicated, for instance, that there had been some affrays between Iranian and Afghan subjects in Sistan as a result of continued disputes in connection with Hirmand water distribution.22

As friendly relations developed in the 1930s between the new and centralised government of Reza Shah Pahlavi in Iran and the independent government of Mohammad Nader Shah in Afghanistan, fresh attempts for the settlement of Hirmand water disputes resulted in the conclusion of the 1939 treaty. Article I of this treaty recognised that "the governments of Iran and Afghanistan agree to divide in equal shares all waters of the Hirmand river which flows to Band-e Kamal Khan (30 miles inside Afghan territory) between Iran and Afghanistan," and Article II provided that in order to use more water than that is taken now between Deh-e Chahr-Borjak and Band-e Kamal Khan, the government of Afghanistan would not construct any other stream in the said district and not even repair any of the existing ones.23

This treaty, though in line with the accepted international standards and a significant improvement of McMahon's water award, from the Iranian point of view, also failed to put an end to the disputes, mainly because the Afghans failed to agree on it amongst themselves and because of the changed political circumstances in Iran during World War II when the British and the Russians exiled Reza Shah in 1941. The Afghans refused to ratify the treaty and the disputes were revived, especially after the Americans began the construction of diversion dams and canals on the river as a result of contracts they concluded with the Afghans in 1945. The Sistan population was convinced that the consequence of these dams and canals was going to be immediate. The political diary of the British Consul General of Mashahd records a long spell of drought in Sistan in the summer of 1947. It remarks:

"From Zabol a report has been received that no water from the Helmand has reached the town for a month and that outlying villages have been without it for some three months. The drought-stricken population will not believe that failure of last winter's snow is the reason and they have expressed their intent of crossing into Afghanistan and forcibly release the water on which they depend and which they are convinced the Afghans are illegally stealing or diverting by their new American engineered irrigation scheme in the neighbourhood of Girishk." 24

Having inspected the new diversion canal in Afghanistan in 1947, the Iranian Ambassador reported to his government that the canal was 65 miles. The depth of water all along the canal was 2 metres and its breadth 30 metres reducing progressively until 12 metres at the end. It carried between 15 to 20 thousand square feet of water which was meant to go to Sistan.25

The construction of two major dams, Kajaki reservoir and Boghra diversion in Afghanistan in 1949 caused great uproar among Iranians. The two countries eventually sent representatives to Washington in 1959 for negotiation through American mediation. These negotiations failed to achieve any result26 and the disputes continued until 1973 when the two countries prepared a draft agreement regulating their respective water share of the delta region, which failed to be ratified.

According to the abortive 1973 treaty, Iran was to receive a 22 cubic metres per second of Hirmand water in the delta region as its share, and was to purchase an additional four cubic metres per second from the Afghans, summing up to 26 cubic metres per second.

The quota of 22 cubic metres per second became the basis of the Afghans' argument since it was determined by a so-called impartial commission which was set up by the Americans in 1948 to determine the water needs of the two sides in the delta region.27Although this amount per second of Hirmand water for Sistan was even less than the amount of one-third determined by Colonel McMahon's arbitration award of 1905, the Afghans had declined to accept it. The quota, nevertheless, became the cornerstone of their argument at any negotiation thereafter. The Afghan Coup d'etat of 1973, however, prevented ratification of that year's treaty. The Iranian monarchy was, too, overthrown by the Islamic Revolution of February 1979. Subsequently, Afghanistan was occupied by the former Soviet Union, and their puppet government of Dr. Najibollah collapsed in 1992. This development resulted in a civil war in Afghanistan which is still prevailing. These events prevented the two neighbours from making fresh efforts for the settlement of Hirmand water disputes between them. Paradoxically, it must be said that, the prevailing political chaos in Afghanistan has resulted in lack of administrative and technical control of Hirmand water and the free flow of water in the delta region has restored Lake Hamun, albeit temporarily. The Iran-Afghanistan disputes on the Hirmand water rights, however, have played a major role in the two countries' relationships, preventing cooperation between the two with an increasingly disastrous environmental impact on the Sistan province and its population.

The geographical catastrophe taking place regarding Sistan and Lake Hamun is almost an exact, but more slow, repetition of the catastrophe which diminished Lake Aral in another corner of Central Asia where the Soviets diverted a large body of river Amudarya (Oxus) thus creating an environmental disaster of major proportion.

Settlement of Hirmand disputes is long overdue and I make the following recommendations in the hope of paving the way for a morally and technically acceptable solution to the problem:28

1. Complete depolitisation of the Hirmand issue both in Afghanistan and Sistan. Hirmand has never been a national issue in Iran since McMahon's water and boundary awards of 1905.

2. Both nations of Iran and Afghanistan should become fully and consciously aware of the fact that the Hirmand river, below the confluence of Arghandab, particularly below Band-e Kamal Khan, is not the exclusive right of either one of them, and that both Sistan of Iran and Nimrouz of Afghanistan have rights to the river in accordance with their agricultural prospects and water needs.

3. Carrying out thorough surveys of agricultural lands and irrigation possibilities in Sistan and Nimrouz provinces and determining the scale of the annual water needs of each.

4. Distributing the Hirmand water to Sistan and Nimrouz provinces in accordance with the determined annual water needs of each.

5. Undertaking joint venture for investment on construction of regulatory and reservoir dams in suitable places below the confluence of Arghandab.

6. Embankment and regulation of the course of branches and channels on both sides to prevent wastage.

7. Embankment of Hamun and rehabilitation of the Shileh Shallaq.

8. Establishing at Kuhak (where the two countries' boundary starts) on the Parian-e Moshtarak a permanent dam with sluice gates to regulate subdivision of waters between Iran and Afghanistan in that section.

9. Implementation of a rational canalization to ensure an equitable distribution of the irrigable waters, eliminating wastage and unlawful uses of water.

10. Construction of reservoir dams wherever possible to conserve flood waters in the two provinces of Sistan and Nimrouz, which will be of noticeable benefit to the irrigation needs of the region.

1Hamun is an ancient Persian word meaning "Lake".
Official Statistics in 1986, Census Taking Centre of Iran, The Census of 1986, Vol. 142-3,p.1
3 Hirmand is also an ancient Persian word meaning "abundant in water".
4 See geography of Lake Hamun in Pirouz Mojtahed-Zadeh's "Evolution of Eastern Iranian Boundaries", Ph.D. thesis, University of London 1993, pp.89-99.
5Italconsult, "Socio-Economic Development Plan for the South-Eastern Region", Rome 1959, p.48.
6 Pirouz Mojtahed-Zadeh, op. cit., p.96.
7 G.P. Tate, "The Frontier of Baloochistan = Travel on the Border of Persia, and Afghanistan", London 1909, p.237.
8Pirouz Mojtahed-Zadeh, op. cit., p.100.
9 As quoted in Italconsult's "Socio-economic....", op. cit., p.52.
10 Ibid.
11 Omur-e Ab-e Sistan, a report by the Governorate of Zabul, dated Feb./March 1995, p.6 - courtesy of Mr. Mohtadi of the Centre for Middle East Scientific Research and Strategic Studies - Tehran.
12Paragraph 3 of clause 69 of McMahon's Memorandum of 25th September 1904 on Sistan Water Question, FO 60/727.
13 Pirouz Mojtahed-Zadeh, op. cit., pp.578-81.
14 Extract of Goldsmid's Sistan Boundary Award regarding Hirmand river, last paragraph, as appeared in General Goldsmid's book "Eastern Persia", London 1876, p.414.
15 Pirouz Mojtahed-Zadeh, "Eastern Boundaries of Iran" in The International Boundaries of Modern Iran, ed. K.S. McLachlan, UCL Press, London 1994, p.135.
16 McMahon's Memorandum, op. cit.
17 McMahon's Final Draft of Water Award, Award "B", No.29 of FO 60/728, pp.34-6.
18 Paragraph 82 of McMahon's Memorandum, op. cit.
19 Colonel McMahon's Telegram No. 947 to the Foreign Secretary of Britisch India, 12th April 1905, enclosure No. 6, FO 60/728, p.8
20 Copy of the report of the Russian Legation at Theran to H.I.H. The Vali-ahd (Crown Prince), July 20, 1905, FO 60/729, p.48
21 From British India Office to Foreign Office, 23 November, 1905, FO 60/729 p.280
22 Paragraph 97 of Confidential Diary of H.B.M. Consul for Sistan for 15 Nov. to 31 Dec. 1929, FO 371/14526, p.3 of 211.
23 Articles I and II of the Iran-Afghanistan Treaty of Hirmand Water Division, dated 6 Bahman 1317 (26 January 1939), text in Persian. Document in the Document Centre of the Islamic Republic of Iran's Ministry of Foreign Affairs.
24 Extract from Secret Political Diary of British Consulate General Meshed, No.8 of 1947, dated 5 August 1947, FO 371/62024.
25 Extract from telegram No.252, from the Iranian Ambassador in Kabul to the Foreign Ministry of H.I.M. Government of Iran, 1947, but no details of the date, Iranian Documents of the Office of Prime Minister, Series No. 102010.
26 Private notes of Prof. M.H. Ganji, Secretary of Iranian Mission to the Washington negotiations, sent to this author on March 9, 1991.
27 Private information provided to this author by Amir Hussein Khan Khozeime-Alam, Iran's Deputy Minister of Agriculture in 1948 who was personally involved in the work of the so-called Impartial Commission in that year. He was interviewed on April 10, 1991.
28 Pirouz Mojtahed-Zadeh 1993, op. cit., pp.657-8.


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