INP-WealthPk

Rainwater Harvesting is Solution to Avert Water Crisis

February 17, 2022

By Ayesha Saba ISLAMABAD, Feb. 17 (INP-WealthPK): Pakistan is suffering from severe water scarcity amid depleting freshwater resources in the face of the growing population. The influx of rural population to urban areas has made the matters worse, disrupting the natural ecosystems, significantly increasing the demand for the commodity, thus throwing water supply networks under stress. While countries around the world have over the years developed technologically-advanced methods to conserve water by making use of greywater and wastewater, desalination and rainwater harvesting (RWH), Pakistan lags behind. Of late, RWH has got notable attention around the world and is considered to be the best alternative source of domestic water supply. Rainwater harvesting is a process of collecting and storing rainwater from various catchments (rooftops, roads and station areas) during rainfall, and conserving it in tanks. This concept is increasingly used to deal with water scarcity and urban flooding. It is also an important source of recharging the groundwater, which can be used for drinking and non-drinking purposes, including irrigation and farming. Developing countries like Pakistan have yet to develop efficient RWH systems to conserve this precious source. Pakistan, a semi-arid region, is currently going through its worst water crisis due to being prone to natural disasters, demographic changes, rapid population growth along with urbanisation, industrialisation, agricultural intensification, and changing lifestyles. Monsoon rains account for 60% of total rainfall in Pakistan, but the country does not have the capacity to store the rainwater for later use as its lacks a rain-harvesting infrastructure that makes use of dry ponds, canals, and low-lying places for storing water. This extra water could also be stored in specially-designed dams, reservoirs and underground tanks during heavy rainfalls, such as those seen during the monsoon when rivers and canals overflow. This not only prevents flooding in urban areas, but also saves water for later use in crisis situations. Pakistan receives an average rainfall between 200-1,500 millimetres per year, much of it in the short span of two months.

Source: Pakistan Meteorological Department

According to the Meteorological Department, most cities receive 700 millimetres of rain yearly, but almost all of it either goes down the drain or is absorbed by the earth. That amounts to a great loss. It says if one millimetre of rainwater over one hectare is saved, it can provide 10 cubic metres of fresh water for all purposes. January 2020 was the wettest month on record, with Pakistan receiving 133% above average rainfall, the second heaviest since 1961, causing flooding across the country. This additional water could have been saved if the country had the storage capacity. This massive wastage of the commodity at a time when Pakistan is facing severe water shortage has moved some in the higher echelons, with the agriculture department of Punjab launching a rain-harvesting project. Under the programme launched in the Rawalpindi division, the department has so far completed the construction of 44 ponds against the target of 180. It plans to replicate the project in other districts of the province as well to improve the underground water table and have enough water for irrigation and drinking purposes. Speakers at a recent UN-Habitat Pakistan seminar hosted by the ministry of climate change recommended engaging stakeholders and partners at the national and provincial levels in order to promote rainwater harvesting to tackle water scarcity issues for metropolitan and secondary cities. According to a research carried out by the Climate Change Adaptation Project of the World Wide Fund for Nature-Pakistan, “There is a dire need to utilise 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.” It becomes essential that the government takes charge of one of the most pressing issues and enhances coordination among stakeholders and partners for future collaboration in the rainwater harvesting sector. All public sector buildings would have to install RWH systems to conserve and reuse water. In order to spearhead rainwater harvesting projects, the government will need to boost its financial investment.