GROUNDWATER AND EMERGING CHALLENGES IN PAKISTAN

 

GROUNDWATER AND EMERGING CHALLENGES IN PAKISTAN

 

1,           AVAILABILITY

Pakistan is an agriculture country. Agriculture contributes 40% in employment share and 60% in import earning. Ground water is one of the various resources which plays vital role in areas where the irrigation system is not fulfilling the irrigation needs. Pakistan primary ground water resource is in the irrigated areas of the Indus Basin, while the secondary source is the area outside the Indus Basin. Indus basin is underlain by unconfined aquifer covering about 40 million acres (MA) of surface area of which 15 MA is fresh and 25 MA is saline. The aquifer receives its direct recharge from natural precipitation, river flows and continued seepage from canal, distributaries and watercourses. Indus basin aquifer ranked as the 2^nd most over stressed underground water reserve in the world. It contributes more than 50% in agriculture sector, around 70% in domestic use and 100% in industrial sector.

The safe yield of groundwater is 53.3 MAF (Punjab 40 MAF, Sindh 10 MAF, KPK 2.4 MAF and Balochistan 0.9 MAF. The groundwater potential and use in AJK is very limited as compare to others provinces

Table.1.1            Estimated province wise groundwater balance

 

Parameters	Punjab	Sindh	KPK	Balochistan	Total(MAF)
Rainfall recharge	9.90	1.96	0.87	1.21	13.94
Recharge from canal system	21.7	6.76	1.00	0.29	29.75
Return flow from irrigation	7.08	8.58	1.02	0.37	17.05
Domestic and industrial return flows	0.57				0.57
Other return flows		0.79	0.13	0.08	1.00
Recharge from rivers	3.50	0.30	0.13	0.18	4.11
Total	42.75	18.39	3.15	2.13	66.4 MAF
Groundwater abstraction (Private STWs and PTWs)	31.50	3.49	1.77	0.45	37.21
Groundwater Abstraction (domestic and Industrial)	2.50				2.50
ET losses	8.75	13.75	0.24	1.13	23.87
Subsurface outflows/change in GW			0.90	0.41	1.31
Baseflow to Rivers		1.15	0.24	0.14	1.53
Total	42.75	18.39	3.15	2.13	66.4   MAF

 

2,           DEVELOPMENT

Large scale extraction and use of groundwater for irrigated agriculture in Indus basin started in 1960 from SCARP) project. Development of groundwater remains key focus and its management could not get full attention which resulted in uncontrolled and unregulated abstraction of this precious resource. Average annual abstraction of groundwater is more than 55 MAF which has already crossed the safe yield limit. Historic data shows that around 1.2 million private tubewells with average discharge of 1 cusec are working in Pakistan. Out of these 800,000 are in Punjab. Now although there is clear evidence that groundwater is being over-exploited, yet 10,000 additional wells are being put into service every year. According to recent estimated 13% of these tubewells are run by electricity whereas rest of 87% use diesel engines. Diesel engines are preferred by farmers due to low installation cost and assured operation.

Groundwater exploitation has brought numerous economic and environmental benefits. It transformed the concept of low and uncertain crop yield to a more secure and predictable crop production. Crop production increased from 20% to 100% and use of groundwater in conjunction with canal water supplies has helped in maintaining the salt balance in the soil. Canal water supplies are 40% deficient of crop water requirement which is fulfilled by groundwater. About 80% farmers used groundwater in conjunction with canal water whereas remaining 20% totally dependent on groundwater. Area irrigated by groundwater has increased from 6.7 to 8.4 MA whereas the area irrigated by canal water has decreased from 19.5 to 17.0 MA.

 

3,           PROBLEM DEVELOPMENT

3.1   Overdraft/over-exploitation

              Unregulated and uncontrolled use of groundwater is diminishing the relative accessibility. Depth to water table has decline in many areas of the Indus Basin which is evident that there is serious imbalance between abstraction and recharge. Due to excessive urbanization and construction of impermeable membrane over the natural strata, rate of groundwater extraction is much higher than its recharge rate. Many tubewells have gone out of production whereas production of remaining wells has reduced below 50% in many areas. Due to prevailing situation of this increased in depth to water table, bore depth has to been increased which ultimately led to salt water intrusion in fresh aquifer in many areas and increased in installation and operational cost. Depletion of groundwater is more in non-canal command area where irrigated agriculture is only dependent on groundwater.

              Excessive mining of aquifer in fresh groundwater area has resulted in falling water tables and groundwater has become inaccessible in 15% and 20% of the irrigated area of Punjab and Baluchistan respectively. The electricity for pumping groundwater is heavily subsidized in Baluchistan. The construction cost of deep electricity tubewell (greater than 65ft) is five times as compare to shallow tubewells (less than 20ft). The rich farmers having deep tubewells are the real beneficiary and poor are not getting benefit of this subsidy which ultimately creating unrest in society. This policy also exacerbating the problems of groundwater over-draft in Balochistan.

      3.2   Deterioration of Quality

              Groundwater under the Indus irrigation system is plentiful however quality is constraint. Key indicators to determine the quality of groundwater are EC, TDS, SAR and RSC. Quality of groundwater in Indus Plain varies widely, both spatially and with depth. Around 77% (10 MA) area of Punjab has access to fresh groundwater. Saline water is mostly encountered in central doab area and Cholistan area in southern Punjab is well known for highly brackish water unfit for drinking purpose. In some parts of Punjab, there are also reports of high fluoride content(7-12mh/l) and high concentration of arsenic (50 ug/l) in groundwater. In Sind province, about 28% of area has access to fresh groundwater. Large areas are underlain by poor quality of groundwater. In Sindh, the area of fresh ground water is confined to a narrow strip along the river Indus. Excessive pumping of this layer is causing salt water intrusion into fresh groundwater areas which resulted in abandoning of about 200 public tubewells located in fresh groundwater zones of Sindh province.

      3.3   Management Issues

The groundwater use has almost reached the sustainable limit. Increasing population and industrialisation has put this precious resource under severe stress. In IBIS, groundwater is usually used in conjunction with surface water which helps the farmers in decreasing the salinity of irrigation water in an attempt to avoid soil salinization. In most of the canal command areas, conjunctive use of ground water and surface water is equally practised in head and tail end of canal system. One of the key disadvantages of this unmanaged conjunctive use is that upstream areas are subjected to water-logging whereas tail end users are aggravating their salinity problems due to bad quality of the groundwater. Therefore, effective conjunctive use should be encouraged that will allow a combination of surface and groundwater to farmers in such a way that equity in availability of water of acceptable quality is ensured all along the channel.

Pakistan must learn that development of groundwater resources without proper planning and management strategy has paid back very badly. Therefore, Pakistan needs a serious debate about whether to pump their aquifer to maximum and face the consequences thereafter. Or be more proactive now, better manage abstraction and invest in recharge today. Protecting groundwater through management and technical measures like regulatory framework, water licensing, artificial recharge especially for threatened aquifer and should adopt integrated water resource management concept

4,           CONCLUSION

              Groundwater management in Pakistan has received no attention, many aquifers have come under severe stress thus threatening sustainability of this resource.

            The level of groundwater extraction has reached its peak. A management and regularity authority are urgently required to save it from an undesirable depletion as well as deterioration.

 

5,          WAY FORWARD

There is dire need to develop regulatory framework for efficient utilisation of groundwater. An effective monitoring and management system that encourages groundwater sustainability is needed. Initial focus should be given to groundwater monitoring and gradually shifted to the groundwater management.

Data regarding groundwater percolation and recharge based on approximation because no scientific data is available so far. To get precise information of fresh ground water zones, how much water annually percolates, ground water depletion rate, the most important exercise which need to be done is to define the boundaries of ground water basin. Before preparing any master plan for control and regulation of groundwater, more precise and reliable data need to be collected.

Storing water underground will be equally useful particularly during drought year. This can be achieved by recharging aquifer through various technologies. A case study reveals that there are 27 potential sites available on the Punjab rivers for small storage using inflatable rubber dams.

The awareness campaign regarding groundwater issues, self-regulation, groundwater monitoring and management interventions need to be started through electronic and print media. Water conservation topics should be the part of syllabus at primary, secondary and tertiary level education system. Media and non-government organisation (NGOs) can play pivotal role.