Floods are becoming quite common in our cities now a days. But its should be noted that floods in our cities are mainly caused by the uninformed manner in which cities are interfering with the natural water cycle. The impact of climate change, rapid urbanization, and deteriorating and outdated infrastructure are aggravating current water challenges of flooding, water scarcity and rehabilitation costs on a scale that will overwhelm the capacities of most of the urban local bodies.
At the same time, by implementing stormwater harvesting the problem of flooding can be addressed. Stormwater harvesting in public parks and open spaces provides a unique opportunity to utilize the excess urban run-off for groundwater recharge, at the same time providing space and time for flood waters in case of moderate and extreme rainfall events, thereby allowing the drainage system to cope with the excess run-off.
In cities we have thousands of acres of land that is used as planned open spaces, which provide an opportunity to harvest stormwater. This potential can be realized by allocating only 2–3 per cent of the area of these parks to stormwater harvesting structures.
Instead of allowing the excess run-off in urban areas to flood cities and wreak havoc, it is important that we create mechanisms to harvest this run-off by implementing green infrastructure solutions.
This would eventually help in transforming the cities into water-sensitive cities. Parks provide ideal opportunities for stormwater harvesting as they are often highly visible, multifunctional public spaces. Parks are a common land use feature in the cities of Uttar Pradesh and can be used to their maximum capacity to recharge groundwater.
Recently, the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) has stated that extreme climate events are occurring frequently, and these are projected to become more frequent due to changing climate. In future, high intensity rain over fewer rain days is expected to become normal, thereby generating high volumes of run-off in a short time-period, which will increase vulnerability towards urban flooding. In addition to the various ecological, hydrological and drainage benefits, stormwater harvesting in parks and open spaces will also strengthen the resilience of cities to tackle moderate and extreme precipitation events due to climate change.
Rainfall can be converted into an important and manageable resource by contributing only 2–3 per cent of open public space for harvesting infrastructure. India being the second worst flood-affected country in the world, has one of the toughest tasks in hand which can be solved without incurring much costs. Stormwater harvesting is the best method for us to solve the urban flooding problem which is becoming more frequent now than ever before.