Nowhere is the water shortage in all forms and usages more pronounced than in the largest administrative land mass of Pakistan. Not too long ago, the resources met the requirement for sustainable living of the rather reclusive population. But with emergent demands on municipal water supplies and the rewards of higher agricultural production, the stress has now turned to strain and the government is bereft of options in both restraint and augmentation of supplies. Perhaps the threat of rampant urbanization would be recognized as a greater sore than the agricultural withdrawals owing to the difference in capacity, frequency and depth of withdrawals between the two uses.
Aside from the coastal and desert environments, the priority would be the plains and the highlands that constitute the growth engine for the Province. But with trending decline in rainfall and associated groundwater levels coupled with the continuing penchant for tube well waters, a major governmental initiative to regulate harvest and distribution of supplies is required. According to a report submitted to the Senate in year 2015, over-abstraction of groundwater in Balochistan exceeds the rate of recharge by 22%.
The current estimate of installed base of tube wells is over 43,ooo, up from the near 30,000 two decades ago. And not everywhere is the aquifer offering a confortable bore depth, meaning water has to be abstracted from depth that is financially not sustainable. Emergent official estimates indicate that almost 50% of the irrigated land is owed to canal waters and about 39% to tube wells. The once popular Kareze system has dwindled to a 7% share and a mere 4% of the land is irrigated by traditional open wells. Canal waters sustain a small part of the system whereas the reigning land mass lies further in the highlands of Pishin, Loralai, Killa Abdullah, Killa Saifullah and Ziarat where groundwater contribution is critical to sustain high value crops.
Unfortunately, it is a bit too late for referral to sustainable irrigation supplies given that 30 of the 32 districts of Baluchistan have lost food security due to drought conditions. UNDP estimates 60-70 percent of population facing risk of drought in different forms with populace in districts of Pishin, Killa Abdullah, Mastung, Kalat and Loralai humbled by socioeconomic fallout in the form of reduced employment, sale of agricultural assets and even migration. Common perception is that recovery has not been possible from the drought of 1997-2005 with non-retractable impact on the water tables.
A rational approach to thwart the impact of drought would necessarily oversee groundwater conservation in all manner and forms of legislation and abstraction in favor of less reliance on water-intensive crops and more on drought-tolerant crops with quick maturity. In Pishin, Qila Saifullah and other fruit producing districts a number of orchard owners now prefer micro-irrigation system over conventional sprinkling and flood and furrow system. But then, augmenting the aquifers through effective recharge mechanisms would be the mainstay of the entire redemption process.
To add to the legitimacy of such an initiative, following is an itemization of the steps that are required to effect a quantifiable change in aquifer recovery based on minimum legwork by Govt. agencies.
1) There is no point in visiting a settled economy of people as they won’t divest from their current practices. Instead, it would be prudent to visit the land in terms of a robust monitoring mechanism to establish the flux in the regime over wet and dry cycles. Without this knowledge, the propensity of the recharge mechanism and upper limit on water use could not be established. A water balance model is the gateway to all other informed opinions on the subject. Seemingly, there exists enough latent understanding of how flow lines have been established over the millenia and the accelerated interference in this process caused by uninhibited withdrawals.
2) Flash floods constitute the most dominating lifeline to water impoundment; below the hills the torrents follow natural nullahs and ravines where open wells could be constructed towards direct recharge of the aquifer. This is the established practic in Thar where rainwater finds its way to a complex of wells for ready mix with the water tables. Over sheet flow zones, a network of trenches would do the job towards a fulsome contribution to the vadose zone.
3) Water conservation should be the purview of the Govt., preferably the Fed. Govt. in lieu of subsidies on drip and sprinkler systems. It would free up water for consumptive use and also permit intercropping over contiguous lands. Fresh water for crops and livestock is a potent excuse for sedentary living.
4) Based on a critical score for water table depletion, there should be legal mechanism to inhibit/curtail groundwater harvest. Hydrogeological assessment vide groundwater balance modeling would establish the minimum for annual recharge in order to sustain precribed crop water requirements. A transition to low consumptive use crops is not popular with the masses and therefore a tangible limit needs to be set on the harvestable area (cropping intensity) through the Revenue Department.
5) Recharge zones need to be protected and isolated from cropping and other high intensive uses. Such areas can be marked with afforestation. This way, another stakeholder in the form of Forest Dept. would become a participant in the conservation strategy.
6) For every sub-basin, groundwater allowance needs to be set to not exceed withdrawal limits established by water balance modeling. This could be done on the strength of bulk metering connected to monitoring units through SCADA. Water use should read like a bank statement showing available balance to the end of the season.
7) The Provincial Agriculture Dept. should establish the physical properties of soils in terms of bulk density and porosity such that soils with deep horizons and high transmissibility in the root zone should be marginalized against high value/high consumptive use crops. The revenue Dept., once again, could benefit from this advice in restricting cropping over these zones, or else declare them high tax zones for harvesting.
8) High capacity wells should be capped forthwith. In the closed valley systems of Baluchistan, high withdrawal nodes would cause havoc with the subterranean flow lines and dry up the aquifer with geometrical grace. New well fields should only be propagated if a network of recharge wells has been constructed and allowed to operate over an extended period as a prelude to authentic data collection on groundwater balance and sustainable assessment of withdrawals.
9) An exclusive mapping department skilled in closed basin land use interpretation techniques would be most essential to official oversight. Comparative spatial assessment incorporating data from measuring nodes and satellite imagery would reduce the quantification error to the minimum, trap violations over land use restrictions and allow affirmation of the water delta across natural crop cycles.
The foregoing is a collection of ‘small’ steps that both the Provincial and Fed. Govts. could take to restore the worth of replenishment through groundwater harvesting. These are not just capital intensive works but are backed by community participation and rigorous governmental control. Baluchistan could benefit from different shades of capital intensive works to make groundwater hydrology as an integrand to the cultivated economy thereby instigating awareness to the emergent plight of the land and water resources.
The above suggestions can help the policy makers to invest in the right direction by showing the schema and tools needed to collect and analyze data as part of a systems approach.