Rain for nearly ten to fifteen minutes at a stretch submerges most parts of Dhaka under knee-deep water since almost all the water bodies have either vanished or been grabbed to erect tall concrete structures. Amid hellish traffic congestion and Dhaka’s losing capacity to flush out the stranded rainwater, the city people literally get paralysed during every monsoon. As the rainy season has already set in, it is hoped that people from all sections come forward responding to the need of the hour, that is harvesting rainwater.
Expert opinions must not be forgotten that sufferings of the people, due to water stagnation in the capital, could be healed by at least 10 per cent if rainwater could be harvested. Rainwater harvesting has a great potential to ensure the supply of sweet water for the residents. The policymakers in the administration, therefore, should not remain confined to only performing feasibility studies and signing contracts. With a regular rainfall of around 1,700-2,200 millimetres per annum in Dhaka, rainwater harvesting can be a lasting solution to the worsening water crisis in the city. Experts say at least 15 per cent of the total water supply could be met through this process. Rooftops of Dhaka’s households could be a great means of water reservoir.
A senior groundwater specialist of the Institute of Water Modelling, of late, opined that if 60 per cent of the total rainfall, collecting from concrete rooftops, could be harvested, at least 90 thousand million litres of rainwater could be available annually from which more than 200 million litres of water could be used for daily supply. This could greatly help to deal with the water crisis in the city, especially during the dry season when the Dhaka Water Supply and Sewerage Authority (WASA) finds it most difficult to meet the daily water needs of the residents.
Due to adverse effects of global climate change, rainfall has increased in recent years, which might even deepen in the coming days. And with it might also shrink the pure drinking water sources. An alternative way to cope with the intensified crisis in pure water must be found out. Therefore, apart from government steps, construction of a rainwater-harvesting mechanism in all concrete buildings should be made compulsory. Only then, the best and effective use of rainwater could be ensured, alongside finding out a good solution to the severe water-logging problem of Dhaka city. It is high time we went for rainwater harvesting.
