Pakistan is currently going through its worst water crisis due to being prone to natural disasters, demographical changes, and massive urbanization. This increase in migration toward urban areas is disrupting natural ecosystems which will ultimately increase the demand for household water in the country. According to the information by international agencies, water stress is increasing in Pakistan and for a country whose economy is highly dependent on agriculture, the situation appears alarming.
There are several sources of water for the country with 60% of the total rainwater coming from monsoon rains. Many glaciers feed the river system in Pakistan but the glacial melt off increases the risks of flooding. Moreover, the river Indus and its tributaries provide most of the water needed for irrigation in Pakistan.
Water stress is increasing in Pakistan and for a country whose economy is highly dependent on agriculture, the situation appears alarming.
As far as climate and topography are concerned, most of the rainfall in Pakistan occurs in mountains followed by Pothohar and then the plain areas. The range of rainfall lies between 200-1500mm per year, much of it in the short span of two months. This rainfall can not only be utilised to cater to the issue of water scarcity, but also decrease the chance of flooding of major urban cities. As the groundwater level has been decreasing over the years, it may lead to dire consequences of desertification. The rainfall strode in small ponds can address the water recharge. Moreover, groundwater recharge can be done by various techniques such as rainwater harvesting at the household level in urban areas; developing ponds in our parks and farms; plugging our flood drains, and even diverting our river flows to facilitate artificial groundwater recharge.
Rainwater harvesting or collecting system is the technology that collects and stores rainwater for human use. The infrastructure can vary from simple and inexpensive to complex and expensive. It consists of simple rain barrels, or more elaborate structures with pumps, tanks, and purification systems. The non-potable water can be used to irrigate landscapes, flush toilets, wash cars, launder clothes, and it can even be purified for human consumption.
According to research collaborated by the Climate Change Adaptation Project of the World Wide Fund for Nature-Pakistan; “There is a dire need to utilize rainwater, particularly in the arid zones like Kohistan, Thar, Thal, and Cholistan for agriculture and livestock purposes. Groundwater in arid areas is mostly saline, and therefore, cannot be used”.
The solution of rainwater harvesting has not only catered to the domestic water needs, but has decreased household labour for women. Rain Water Harvesting provides the best possible alternative and supplementary source of water in a situation where existing water sources are depleting and fail to fulfill the needs of a growing population.
Rainwater can be harvested in small communities living in mountain ranges by following different techniques that can cater to both domestic and agricultural purposes. The different methods are diversion and dam system. In the former, a long channel diverts the floodwater to cultivation areas adjacent to valleys. Whereas, in the latter system, a large reservoir behind the dam is filled with floodwater which is then pumped through pipes to numerous sprinklers.
Rain Water Harvesting provides the best possible alternative and supplementary source of water in a situation where existing water sources are depleting and fail to fulfill the needs of a growing population.
Moreover, 80% of the people in the major cities are deprived of access to clean water. This leads to major health problems in the population. Major causes for the looming issues of water scarcity, storage and floods are rapid climate change, growth in population and use of water in agriculture. Exceeding water usage in the country has made it the fourth highest in the world in terms of the water intensity rate which is the amount of water used per unit GDP.
At present Pakistan is described as a water-scarced country because the water availability on yearly basis is less than 1,000 cubic meters per person. If it reaches 500 cubic meters, it will become a country having limited water supply by 2025. It is believed that Pakistan has already crossed the “water scarcity line” in 2005, according to the Pakistan Council of Research in Water Resources (PCRWR). If the issue prevails, it could have a drastic impact on the country’s geopolitical, economic, and ecological terrain.
Furthermore, the treated rainwater needs to be stored for its efficient use. In urban and rural areas, there exist vast opportunities to store rainwater by constructing rain-harvesting infrastructure by utilising dry ponds, canals, and low-lying areas. Thus, during heavy rainfalls, such as those in monsoon, when rivers and canals overflow, extra water could be preserved in specially constructed dams, reservoirs, and underground tanks. This would not only prevent flooding of the urban areas in future, but also conserve the water for later use in times of crisis.
Earthquake Reconstruction and Regulation Authority Water and Sanitation (WatSan) experts along with international partners took an initiative based on careful calculations, to revive and develop the age-old practice of rainwater harvesting. It was estimated in the pilot project that no less than 140,000 litresof water (32,000 gallons) with 90% efficiency could easily be collected every year from a house comprising 2-3 rooms with a 30×30 ft roof (100 sq m). Some 12000 Rain Water Harvesting Systems have been installed in school buildings, houses and hospitals across 20 Union Councils of AJ&K and KPK. Moreover, the organisation has taken steps to make rainwater harvesting compulsory in all new buildings. The system provides a simple and easy way of collection, management, and effective utilisation of rainwater at a minimal cost. The project has been successful in the earthquake-affected areas.
The Punjab government after a successful experiment in rainwater harvesting has decided to replicate the project in other districts of the province, in addition to the construction of two more underground rainwater storage projects in Lahore. The stored rainwater in the underground tanks is aimed to be utilised for horticulture and drinking purposes after purification. The Pilot Rainwater Harvesting Project initiated by the Capital Development Authority will also provide clean drinking water, while recharging the local water table for the city’s nearly 1 million residents through collection tanks at the Faisal Mosque complex. Thus it becomes essential that the government takes charge of one of the most pressing issues. Further methods to trap rainwater should be devised by the use of technology and should be used to recharge underground aquifers, ensuring more water for the future.
In essence, an increase in financial investment is required from the government to spearhead rainwater harvesting initiatives. If such measures are not taken, Pakistan is likely to face a disastrous water emergency in the future.