MUHAMMAD ARIF WATTO
Pakistan is close to being classified as a ‘water scarced’ country from ‘water stressed’ country, according to the Asian Development Outlook 2013.
The current per capita water availability of about 1100m3 has been decreased by almost 400pc since early 1950s, and is further projected to decrease by 375m3 by 2025.
As the population grows, the agriculture sector needs to grow in order to meet the food demands.
Farming heavily relies on irrigation water supplies from both canal water and groundwater. The surface water supplies are not only deficient but are highly skewed over time and are unevenly distributed across the Indus basin.
Currently, Pakistan meets more than 50pc of its overall irrigation water requirements through groundwater extractions.
Pakistan is the fourth largest groundwater withdrawing country with an estimated 60km3 extraction of groundwater each year. In terms of extraction, Pakistan accounts for about 9pc withdrawals of the global groundwater which constitute 4.6pc of the global groundwater-fed cropland.
Between 2000 and 2009, the over-extraction has resulted into annual depletion of on average 3.61km3 of groundwater, lowering groundwater tables rapidly in many parts of the country.
Recently, the Nasa’s Grace (Gravity Recovery and Climate Experiment) satellite based observations have identified several hot spots of groundwater depletion, with the highest depletion rates in north-east Pakistan and north-west India.
Many hydrologists are of the view that that there could be 10-20 metres decline in groundwater levels in the upper and the lower region of the Rachna Doab in North-East Pakistan in the next decade. Many tubewells in Punjab and Sindh, and much of the Karez system in Balochistan have collapsed due to declining of groundwater tables. The tubewell irrigation has affected groundwater quality and lowered its tables resulting in drying up of many karezes and dug wells.
Salinity is, perhaps, the most intriguing impact of over-use of groundwater in irrigation. Almost a decade ago, it was reported that more than 6m hectares of land was affected by different levels and types of salinity.
Besides salinity, other important negative environmental externalities include; salt water and sea water intrusion, land subsidence and disintegration of various ecosystem components in different parts of the country.
Though groundwater has a share in irrigation supplies, there is no mechanism either to protect groundwater from overdrafting and polluting.
In the absence of a governance policy mechanism, the ubiquitous nature and open access to groundwater makes it highly vulnerable to misutilisation. Moreover, there is no comprehensive information available within hydrological, ecological or socio-economic perspectives. There is also no system to record groundwater withdrawals and recharge rates.
One of the most alarming factors is lack of public knowledge and awareness towards groundwater resource situation, government and institutional negligence and apathy towards groundwater management and governance policies and practices.
Transitioning into growing water intensive crops such as rice and sugarcane which was encouraged through open groundwater extractions was not a wise strategy given the water resource endowments in the country.
Given the current state of water resources, a shift in the conventional water use strategy and an immediate focus on encouraging water efficient crops is required.
A sustainable groundwater extraction policy needs to be enforced immediately in order to ensure the longevity of groundwater resources. And that should be coupled with compulsive measures to protect the common pool resource from degradation.
The writer is an assistant professor at the Institute of Agricultural Extension and Rural Development, University of Agriculture, Faisalabad.