The Indus plains constitute 34 million hectares of cultivatable land, where the annual recharge of the groundwater system is estimated around 55 MAF, of which 39 MAF is being extracted annually. Monsoon and western disturbances make up the rainfall of the country with 70 percent of it occurring from July to September. The Indus plain receives a seasonal rainfall of 212mm and 53mm, respectively. Pakistan is home to some of the largest glaciers in the world, outside the Polar Regions which account for about 13,680 sq km of the country. The snow and ice melt from the glaciers of Upper Indus catchment supply approximately 80% of the water in Indus River in summer.
One of the reasons why Pakistan suffers greatly with respect to water is because of its weak lower riparian status. Also, the country does not have a good supply-side management structure. This results in wastage of almost 35% of its water resources. An imbalance in water distribution across Pakistan is also another reason for some areas getting less water than required.
In Pakistan, agriculturally inefficient irrigation uses up 97 percent of the country's water resources to support one of the lowest productivities in the world per unit of water. Pakistan's excessive cultivation of water intensive cash crops like sugarcane has increased stress on water. Thirty eight percent of Pakistan's irrigated lands are water logged and 14 percent are saline; and saline water has intruded into mined aquifers in Pakistan. There exists an alarming level decline in water tables in Balochistan, and an increased reduction in sweetened water in the lower Indus basin. The Indus Basin irrigation system, the only source of water in Pakistan, is vulnerable and there exists a need to explore alternative water resource development and management techniques. Dams are losing their ability to supply water. For example, the Tarbela Dam has lost 30 percent of its storage capacity since the 1970s and now retains so little water that irrigation supplies are threatened.
Pakistan's water storage capacity has remained all these years limited to only 30 days against the minimum required capacity of 120 days and recommended capacity for around 1,000 days given its climate. Of Pakistan's total area, nearly 13,680 sq km is covered by glaciers that help boost river turnoff in warm weather. According to scientists, in just a period of 30 years, glaciers in the Himalayas have diminished by nearly one-fifth and it is feared that glaciers in this region will have disappeared in the next 20 years.
Despite being a water stressed country we continue to waste water, refuse to promote conservation and at the same time do not hesitate to pollute fresh water by draining into the river system all kinds of industrial, chemical and agriculture waste.
A glaring example of this situation is river Ravi on the banks of which is located one of our most modern cities - Lahore. Inhabitants of cities located on the banks of rivers in other countries take very good care of their rivers and also take pride in living in such cities. But citizens of Lahore seem to be in complete denial of Ravi. They seem to ignore its very existence. Nobody in Lahore seems to be aware that Ravi has become virtually a dirty sewer contaminating the entire civic life.
While the official managers of Lahore continue to pour billions into its modernisation efforts like the launch of Orange train system project without a thought to the city's heritage the very foundations of Punjab's metropolis are being eroded from underneath as Ravi is fast becoming the most polluted river of the country threatening the entire irrigation system as well as the ground water on which our agriculture crucially depends. Unless we take immediate steps to cleanse Ravi of its pollutants not only the city of Lahore but our entire agricultural sector is likely to be reduced to a swamp by the end of next decade.
In the suburbs of Lahore farmers are using untreated sewage/industrial waste for vegetable and fruit production that are prone to heavy metal contamination.
Presence of toxic heavy metals in irrigation water especially downstream of the River Ravi is also causing serious damage to animal life in surrounding areas.
One of the direct economic impacts of untreated wastewater is the loss of fishery catches, which affects incomes and has nutritional and health impacts on consumers.
Use of contaminated water for agricultural purposes has made heavy metals part of food chain while its consumption is causing people to get waterborne diseases that is putting a huge burden on healthcare infrastructure. Typhoid, cholera, dysentery and hepatitis are on the rise as public at large has no access to clean drinking water. The entire municipal waste of the city is going through fourteen drains untreated causing great damage to waters of Ravi. Hundreds of industrial units are throwing their contaminated waste to river Ravi that makes the situation even worse. These units include chemical, food, plastic, poultry, paper, textile, leather, pesticides, paint, pharmaceuticals and many more.
Farmers are using this polluted water for irrigation and milkmen give this water to their animals creating severe health problems. According to the World Health Organisation, all five types of hepatitis are present in Pakistan. Hepatitis A and C are directly related to poor water and sewage system. The combined ratio of hepatitis B and C in Pakistan is 7.6 percent. A recent report of WWF shows that as per the WHO standards, water of river Ravi carries high metal contents and arsenic level putting life at great risk when mixed with underground water and sewage systems. Fecal coliform injurious to human health is also found in drinking water.
After crossing the district of Gurdaspur in India, Ravi enters Pakistan near Jassar about 120 km upstream of Lahore. It flows down for about 520 km and joins the River Chenab.
Downstream, the water is used mainly for agriculture. Diversion structures take the waters to irrigation canals.
With extremely low flows in the winter, the river turns into a dirty drain due to the discharge of municipal sewage from Lahore city as well as industrial flows from industrial clusters at various locations like Kala Shah Kaku-Lahore Sheikhpura Road, Kot Lakhpat Industrial Estate and Multan Road. The Hudiara drain discharges maximum pollution load into the river (around 430 cusecs). According to an estimate, the total daily discharge into river Ravi from point and non-point pollution sources is 2000 cusecs per day.
The pollution increases as the river flows from Jassar to join river Chenab, its quality deteriorates tremendously and it receives greatest pollutant load from Hudiara drain and Deg Nullah from district Lahore. Due to seepage of surface water, pollutants have penetrated into the ground water which has also become severely contaminated. In the areas where industrial drains are present the heavy metals like lead and nickel, etc, have entered into the ground water and ultimately in the food chain.
Fecal pollution is also common in these areas. This has resulted in increased incidence of diseases like diarrhoea, abdominal infections and skin disorders. During low flow or zero flow from India the river is literally reduced to a drain. Of Ravi's total discharge of 28.08 m3/s, 23.43 m3/s is the municipal flow and 4.65 m3/s the industrial flow. The annual flow has gradually declined over years. Between 1922 and 1961 it was 7 million acre feet (MAF), thinning down to 5 MAF between 1985 and 1995 and further to 1.1 MAF between 2000 and 2009. Over 2009-10 it was 0.28 MAF. According to an international panel of experts, the flow should be a minimum 5000 cusecs per day and 25 MAF every five years.
The gradual reduction in Ravi's flow over the past 20 years has brought about devastating effects on the river ecology (particularly the diversity of fish species), ground water quality, socio-economic status and the health of the communities settled along the banks.
The reduced volume of water in the river also leads to lowering of the water table along the banks as there is no recharge with freshwater. Recharge with sewerage water, on the other hand, is very much detrimental for human beings, livestock and crops. (Currently water table in Lahore city is almost 35 meters which is gradually reducing due to over pumping for domestic usage and lack of recharge from the river water.)
The need of the hour is regular monitoring of Surface water and ground water by relevant agencies in order to study the trends in surface and groundwater pollution. Environmental laws relating to protection of water resources should be strictly implemented. Discharge of untreated domestic as well as industrial wastewater into the river Ravi should be strictly curbed. The Environment Protection Agency (EPA) should strictly implement the National Environmental Quality Standards and force industries to install treatment plants. They should carry out random checks to monitor the regular operation of the treatment plans. Public awareness campaigns should also be started in order to educate people about the role they can play in addressing the problem.