February 05, 2007
Irrigation schemes for Balochistan
By Syed Fazl-e-Haider
A Rs1.5 billion project for improving the irrigation system in five districts of Balochistan has been approved by the Central Development Working Party of the Planning Commission. The districts are Quetta, Pishin, Killa Abdullah, Mastung and Kalat.
The project is designed to improve small-scale irrigation schemes through lining of 15 existing channels and improvement of the traditional underground Karez storage ponds and rehabilitation of structures in flood protection schemes.
The key strategic choice made in the project is to formulate it as a part of a long-term framework (12-15 years) which would allow it to enforce and support adoption of basin approach for sustainable planning, development and management of water resources for agriculture.
The project has been divided into three components:1) partial restoration of water storage capacity of Khushdil Khan protective embankment by raising its level by 2.2 metres; 2) remodelling of its spillway; 3) constructing another protective embankment and repairing the headworks and outlet channel.
Balochistan is a water-starved province. The groundwater tables are on decline due to mismanagement of water resource. Besides streams, other sources are at the risk of over exploitation. Underground water channels locally known as Karezes are one of the oldest systems of irrigation here. In the year 2002, the government spent Rs 4 million to revive 100 Karezes. At least, 1186 other Karezes in different parts of the province are in dire need of repairs.
The most important use of water is for irrigation purposes in Balochistan. The extent of cropped areas with different types of irrigation are as follows:
Indus system: 285,300 hectares
Canal diversions: 60,160 hectares
Karez and springs: 44,700 hectares
Open wells: 17,430 hectares
Tube wells: 121,140 hectares.
Total: 529,180 hectares
Owing to the falling water table, studies show deficit in Quetta sub-basin is about 21,000 AF per year and that the aquifer storage will be exhausted in 20 years. Groundwater is depleting. in some places even with one meter per year, especially in the Pishin-Lora Basin. Zhob and Nari River basins are not available for further groundwater development.
Karezes as a tapping groundwater system has come under great stress, because of commissioning of a large number of deep tubewells in the valleys. These tubewells have been instrumental in causing ground water mining and lowering of the water table. The government has imposed a strict ban on the installation of tubewells in certain areas such as Quetta, Mastung, Mangochar, and Pishin.
A no-objection certificate is required prior to the installation of a tubewell. The three statutes dealing with different aspects of water use include Balochistan Groundwater Rights Administration Ordinance (1978); the Groundwater Ordinance XX (1980) and the Balochistan Water Users Association Ordinance (1981).
The province is blessed with extensive groundwater resource. The hydrological map of Pakistan shows that out of total three main hydrologic units, two are located in Balochistan. They are: Indus River basin, Kharan desert basin and Mekran coastal basin. The province can be divided into three hydrological regions: the Nari Basin, the Kharan Basin and the Mekran Coast. There are about 73 small or large rivers and streams constituting the three basins. Only about 30 per cent of this potential of rivers and streams is utilised through different schemes. A comprehensive investigation of all the basins is needed.
The Pishin-Lora Basin is a major river basin in Balochistan covering an area of 16,928 sq km with 10 sub-basins spread over five districts -- Pishin, Killa, Abdullah, Quetta, Mastung, and Kalat -- with a total population of about 1.2 million. Groundwater within the basin is currently being used at rates 2-3 times more than the recharge rate and exploitation has continued despite the situation being deemed critical almost a decade ago.
Investigations carried out before the drought showed that two out of 14 basins (Pishin-Lora and Nari) had been completely exhausted, while six out of the 12 remaining basins had used more than 80 per cent of their water resources. In other basins, the water table was falling rapidly. The situation had been exacerbated during the recent drought through a combination of continued over-mining of depleted aquifers and insignificant recharge. It showed there was an urgent need to undertake measures to rejuvenate depleting aquifers.
A local farmer of Jaffarabad district told this scribe that water scarcity is the main problem. Cotton is the crop that needs lesser water than other crops. He complained that ââ¬Ålocal growers find no market for cotton in the district, as the ginning factory established in Dera Murad Jamali is lying closed. ââ¬ËWe are unable to bear transportation expenses to take our produce to Sindh and Punjab marketsââ¬â¢, he added.
The government promoted cotton cultivation in the province providing incentives to local growers. The incentive package included diversification of cropping pattern, switching over to cotton from rice and provision of better quality cottonseeds to growers at subsidised rates. Balochistan has two types of irrigation systems i.e. Indus gravity-fed canal system that irrigates 230,000 hectares and small-scale irrigation covering about 320,000 hectares annually. Out of 31,799 tube wells, 48 per cent are electrically-operated in the province.
Except Naseerabad district, there is no perennial system of irrigation. It depends on rain, Karezes and tube-wells for irrigation. Naseerabad is the only canal irrigated district that receives water from the tail end of the Indus River system at the time of sowing cotton and paddy.
The long- term water management programme will meet a long felt need of the province for adequate quantity of water, especially the expanding acreage of fruit orchards. The province is rich in groundwater resources offering best projects. Expansion of agriculture and other economic activities will require tapping of its groundwater potential.
There is a need to explore the idea of building groundwater dams, which store water underground, rather than on the surface. Water that is stored in the soil does not evaporate like ponds and streams. It is clean, healthy and free from parasites. The key is to find ways to capture wet season rainfall underground.
The watershed degradation is a problem in the province. It causes decline in groundwater table. The watershed management is aimed at recharging groundwater aquifer, rehabilitating rangelands, controlling flash floods and enhancing fuel wood production in the target area.
In the year 2000-01, cotton was cultivated on 100,000 acres of land and the province produced 112,000 bales of superb quality cotton, more than the estimated target of 100,00 bales. During FY 2001-02, 150,000 acres of land was brought under cotton cultivation and the set target was achieved. What is needed is to establish ginning factories, creating a demand at local level for the crop.
http://www.dawn.com/2007/02/05/ebr4.htm