Apr 06 - 12, 2009

With an existing shortfall of 9 Million Acre Feet (MAF), the country will be requiring 20 to 25 MAF or three to five dams for avoiding impending acute shortage and conditions.

Pakistan would need at least one major reservoir every 10 to 15 years, both for irrigation and cheap hydropower generation.

Figures show an annual availability of surface water in Indus River System at 142 MAF with 104 MAF water channeled through and evaporation and seepage at 42 MAF. Thus, the availability of surface water at farm gate is just 62 MAF.

With 44 MAF under ground pumped water, availability at farm gate is 106 MAF against the total requirement of 115 MAF.

The existing shortage of water is nine MAF with the projected shortage in 2025 at 30 MAF. In agriculture sector, out of 77.1 million acre of land suitable for agriculture, only 44.4 million-acre is irrigated and an additional 22.5 million acres can be brought under irrigated agriculture.

Experts believe that Pakistan may face worst form of water shortage in near future due to increasing demand and depleting storage capacity of the water reservoirs. In 1947, they said, Pakistan had abundant water reservoirs that were rated good. At that time, it was 5,600 cubic metres per person but now in 2009, these reservoirs have reduced up to 1,100 cubic metres per person.

As per international water standard, the country whose water reservoirs are below the 1,000 cubic metres per person is considered at the chronic water shortage level.

Pakistan is expecting to reach this shortage according to the environment and international water experts in near future, they added.

According to an Asian Development Bank (ADB) report, water availability in Pakistan has decreased from 5,000 cubic meters per capita in 1950s to 1,000 m3 in 2007, mainly because of increase in population, inefficient irrigation, corruption, mismanagement, and unequal water rights. It may be mentioned that only 36 per cent of households had tap water supply in 2006-07, up from 26 per cent in 1998-99. The differences between urban and rural areas are stark in this regard 62 per cent of urban households had access to tap water compared to only 22 per cent of rural households.

Experts say most of Pakistan's natural lakes have disappeared over the last 50 years although several new lakes have been created upstream of the dams and barrages on the Indus. Farmers, especially in the Potohar region, have created hundreds of micro-reservoirs that often border natural lakes and provide a rich habitat for aquatic life.

Climate change will certainly have an impact on water resources and their management. As temperatures rise, rainfall patterns are expected to change, increasing the risk of floods, drought, and other water-related disasters in many areas, experts said.

The World Bank says the retreating glaciers of the Himalayas could present the most far-reaching challenge to the South Asian region being a vital life-sustaining resource for the region. With rising temperatures, the ice mass of the Himalayas and Hindukush is retreating more rapidly than the global average thus posing an unprecedented threat to water supplies, lives, and the economies of the region. There were a number of projects initiated with the collaboration of international funding. But, on grounds there has been no result in this regard.

Experts told PAGE that unchecked growth of population has increased pressure on land and water resources. Thus, it has become imperative to conserve our water supplies with proper management. Several reports have shown that about 25 to 30% of the water is being lost due to poor management while more than 5MAF of irrigation water could be saved by lining the minor canals only, and additional amount of about 3.6 MAF could be saved by watercourse improvement.

According to them, proper management, efficient application, and uniform distribution of available water at farm-gate have remained major problems since the existence of the irrigation network. Increasing water demand, deferred maintenance, salutation of channel prism, excessive water by tampered outlets and illegal water extraction & theft all lead towards inequity in the system. It has even become increasingly significant over last two decades. There is inequity in distribution at all levels in the system.

Inequity in water distribution between head and tail is of the order of between 20 to 50 %. The tail enders however, receive 10 to 12 % less share of water, because the allowance is based on the theoretical losses.

Due to shortage of water, they said the tail enders have been forced to use poor quality water without proper mixing, which has given birth to salinity in such areas. This problem could be overcome by lining the whole watercourse. Again, the investment becomes a constraint. It is not possible to line the whole or optimum length of the watercourses.

They argued that water conservation could play an important role in sustaining agricultural development. This requires substantial improvements in water use efficiency, choice of suitable cropping pattern, growing water-efficient crops, and introducing modern irrigation application techniques (trickle. sprinkler etc.).

They said use of water based on scientific lines need to be encouraged while efforts should be made to convert the present rotation-based-irrigation system to demand oriented system. Besides that, the modern irrigation application techniques (trickle, sprinkler etc.), that have potential to improve water distribution and water use efficiencies must be introduced in the areas with water scarcity.

Sources in Wapda said that storages at Tarbela, Mangla, and Chashma were constructed primarily for "Replacement" under Indus Basin Replacement Plan.

These storages with aggregate design capacity of about 15 MAF form about 90 percent of the existing capacity and are losing capacity due to excessive sediment burden in river water. Moreover, due to lack of adequate storage capacity average 35 MAF water escapes annually below Kotri, varying from eight MAF to 92 MAF.

Sources in Wapda told PAGE that Pakistan had potential of 25000 MW thermal power generation. The government was working to build large dams and Bhasha dam was one of them that would be completed in eight years.