RAWALPINDI, Feb 6: Excessive water conveyance losses are occurring in Pakistan due to sedimentation and poor maintenance of irrigation networks, says a new UN report.

The water management efficiency in agriculture in South Asian region also remains much less desired, implying that the current system of operation, and distribution and use of water resources is inadequate.

The age-old irrigation infrastructures must be rehabilitated and remodeled to address the water losses as well as changing agronomic conditions, suggests the report titled ‘Freshwater under threat: South Asia’, jointed published and released on Friday by the UN Environment Programme (UNEP) and the Asian Institute of Technology (AIT).

The report points out that there is a need for more efficient and integrated management of the upper Indus Basin. Unless the problem is properly addressed, the downstream areas will be badly affected and the continuing sedimentation of the Tarbela dam reservoir will cause irrigation water shortages in the future, especially during the Rabi season and the early part of Kharif.

The UNEP report states that water resources in the Indus basin are under considerable stress especially in the eastern parts of the basin shared by Pakistan and India, the latter being due to extensive water use to support agricultural production.

A country-wide assessment of the annual water use of different sectors in the Indus basin reveals that Pakistan is the largest water user accounting for about 60 per cent of the total water use, followed by India at 38 per cent.

The water use for the domestic and industrial sectors is relatively small, being only 3.4 per cent of the total use. The remaining water resources are being utilised in the agriculture sector.

These values highlight the extent of agricultural activities in the basin, and the importance of this sector in countries’ economy.

The total water use of 257 billion m3 indicates that about 90 per cent of the basin’s available water resources are being utilised. Nearly 87 per cent of the Indus basin population has access to improved drinking water sources. Although this proportion may appear satisfactory, a closer look may not be so reassuring, noting that the remaining 13 per cent means that approximately 28 million people in the basin do not have access to improved drinking water sources.

Considering the country level, the population living in the Pakistan portion of the Indus Basin has the biggest access (93 per cent).

Although Pakistan has a clear agreement with India on the use of the water resources of the Indus river, there is no agreement between Pakistan and Afghanistan concerning the water resources of Kabul River, which is a sizeable tributary of the Indus. The riparian issues in the Indus Basin also are convoluted with the border dispute between Afghanistan and Pakistan.

Afghanistan is planning to reinforce irrigation, fishing and hydropower generation along the Kabul River. Unless an agreement is reached, however, further developments could trigger tensions between the two countries.

The Indus Waters Treaty is regarded one of the few successful settlements of trans-boundary water basin conflicts. Regarding institutional capacity, the Permanent Indus Commission is tasked with the implementation and monitoring of activities of the Indus Waters Treaty.

However, this institution is weak in performing the various research studies needed to prepare scientifically-sound responses to water resources development on both sides of the border.

South Asia is home to some of the world’s largest river basins in terms of both catchment areas and water flow volumes. The Indus river is the longest and most important river in Pakistan, as well as being one of the most important rivers on the Indian sub-continent. The river feeds ecosystems of temperate forests, plains and arid countryside.

The report presented a situation analysis with regard to the vulnerability of water resources systems in South Asia. The report considered three South Asian trans-boundary river basins as case studies: Ganges-Brahmaputra-Meghna (GBM), Indus, and Helmand.

Almost 95 per cent of the withdrawn water is consumed by the agriculture sector, a much larger proportion than the average global agricultural water use (70 per cent). In contrast, the region generally exhibits very limited water use in the industrial and domestic sectors.

In view of the uneven endowment and development of water resources in South Asia, the issues and challenges of the water sector are large in scale, diversity and complexity. A number of studies and reports have highlighted the complexity of water issues from natural, political, social and economic perspectives.

The population explosion in the basins during the past century has exerted heavy pressure on its water resources, causing noticeable changes to the functioning and uses of water. About 67 per cent of the nearly 34,000 km2 of Himalayan glaciers are reported to be receding. As the ice diminishes over the long term, glacial runoff in the summer and river flows will decrease, leading to severe water shortages in the basins.

The report says lack of sufficient vegetation coverage can cause severe problems in terms of water conservation and maintaining natural flow regime. Thus, the percentage of land without vegetation coverage was used as an indicator of ecosystem insecurity. At the same time, water quality deterioration as a consequence of water resources development and use, is an important indicator of current ecological health.