Improving groundwater recharge in the drylands of Pakistan

Balochistan is the largest province of Pakistan and is classified as a hyper-arid to arid dryland. The annual rainfall over almost 90% of the area varies from less than 50 mm in extremely dry areas to the west and south-west (where Balochistan is) to just over 250 mm in the upland areas in the north and central parts. Agriculture, particularly livestock, provides the main livelihood for the majority of the population. Apple orchards and vineyards are the major agriculture activity with small ruminants constituting the bulk of the livestock. Rampant poverty and poor grazing practices are two of the main factors responsible for degradation of watersheds in the area.

The biggest challenge faced by the province is water scarcity. In the absence of perennial water sources the population has come to rely on groundwater for meeting their domestic and crop water requirements. This has resulted in the groundwater balance being disturbed; there is an increasing gap between abstraction and recharge. Natural recharge in Balochistan has become less effective due to watershed degradation, particularly loss of vegetation and formation of rills and gullies, so that aquifer recharge is reduced and aridity has increased.

Groundwater recharge

In Balochistan, the efforts to recharge the underground aquifers have been practiced through construction of Delay Action Dams (DAD) by the Irrigation Department at huge cost. Water collects behind these dams but is either totally or partially lost to evaporation. It was assumed that ponding the water in the reservoirs created by the dams would help recharge aquifers by simple infiltration. In practice this has not been successful due to siltation of the reservoir beds and sides caused by fine sediments brought in by the feeding streams. This has required interventions not only to artificially recharge the local aquifers but also to promote water conservation in order to recoup the large investment made in these dams.

To address the problems of groundwater depletion and unwise use of water for agriculture and watershed degradation, a pilot demonstration project was undertaken near Balozai Village in Pishin District. The aim of the project was to augment the water received from the reservoir created by the construction of the Balozai dam. As there are no means to release water from the dam for direct use, this is seriously impeding the recharge of Karezes found in the area, which have gone dry. Karezes are gently sloping underground channels used to transport water from an aquifer under a hill. They create a reliable supply of water for human settlements and irrigation in hot, arid, and semi-arid climates.

As a result of the demonstration project implemented by IUCN, water stored in the reservoir is now being utilized for recharging the land downstream of the dam where a system of Karezes is running that is used for drinking water, agriculture (to irrigate orchards and to grow vegetables) and for domestic needs (drinking, cooking and laundering). There is an expectation that the serious health  problems related to water-borne diseases like dysentery, hepatitis and typhoid faced by the community will be ameliorated following increased availability of new, clean water.

Impacts

Some of the social and environmental impacts of the project include:

• Rise in water table resulting in rejuvenation of local Karezes and enhanced water availability;
• Additional income from fish farming and increased agricultural activity;
• Greening of the local area,
• Better water quality.

A proper measuring system consisting of water meters and water table measurement was installed to help in calculating the water balance. Given the size of the project and the availability of funds, it was not possible to monitor impacts and benefits on the ecosystem. However, students from a local university monitored the impact on the water table.

Despite being a small project, the demonstration had an impact on the Irrigation Department’s policy to construct Delay Action Dams with no downstream outlets. After the commissioning of the Project and its outreach to the senior bureaucrats and politicians (the Governor of Balochistan) the department started designing the dams with an outlet on the downstream side to allow water to flow out and spread on the downstream virgin lands for recharge to take place in alternative ways.

Currently there is adequate knowledge to include new and better technologies and practices in water management policies at the national and provincial levels. The problem is enforcement and scaling-up  of the policies, which requires political goodwill as well as specific knowledge of ecosystem management in Balochistan. In Pakistan, water is and continues to be the single most important factor  in making dryland ecosystems productive to support livelihoods of the inhabitants.

Good water  management practices can benefit poor people whose livelihoods depend on limited available water  resources. The challenge is to work with policy makers to better understand the challenges and to explain to them the effectiveness of good water management practices in drylands so that understanding can improve, investments can be correctly targeted, and wider scale adoption can become a reality. For dry upland areas of Balochistan, the project sends a clear message that the harvested water stored in existing DADs (now acting as evaporation ponds) can be used for recharging depleted aquifers at low investment cost by using the Karezes technique.

What is required is creation of a strong political will among policy makers to not only make use of existing DADs but also construct new dams with leaky structures and/or use this technique as an integral part of the design. The message goes beyond Balochistan as being equally applicable to other dryland areas in the world with similar topography.

Written by Abdul Majeed, IUCN Pakistan. Sourced from Davies, J., Barchiesi, S., Ogali, C.J., Welling, R., Dalton, J., and P. Laban (2016). Water in drylands: Adapting to scarcity through integrated  management. Gland, Switzerland: IUCN. 44pp