The world is running out of drinking water, so it is important to manage the available resources efficiently. The use of rainwater is becoming increasingly popular, both in households and in urban spaces.
By using rainwater in your household, you can reduce your water consumption by up to half. It is perfect for flushing toilets, cleaning, or watering the garden. On a larger scale, rainwater is used in agriculture, industry or for flushing sewage systems. Most often, retention reservoirs are used to collect precipitation, allowing water to be stored until it is actually needed. We decided to investigate and present interesting solutions for the use of rainwater in countries where the technology of rainwater harvesting has been perfected, reaping both the economic and ecological benefits.
New Orleans (USA)
In this city, a neighbourhood was built on previously drained, rather marshy land. Unfortunately, the site suffered during the famous Hurricane Katrina and was once again flooded. The authorities decided not to deal with the excess water in the area any longer and, after rebuilding the district, relied on the accumulation of rainwater. The Mirabeau Water Garden project was created and is currently being implemented. It will have a surface area of 100,000 square metres and the capacity to store around 35,000 square metres of water. Numerous mini-parks have also been created in this difficult area to collect water from the neighbouring plots.
Copenhagen – Tasigne Plads (Denmark)
Umbrella-shaped installations have been set up in the Copenhagen square to collect rainwater, which is then used to water the urban vegetation. In addition, the area has been deliberately landscaped so that the hollows with trees and flowers accumulate as much rainwater as possible, with any excess going into underground tanks.
Industrial estate in Kingston (Australia)
Three streets were renovated and their surfaces replaced with a permeable layer. New rain collectors were installed and 54 infiltration ditches were created along the roads. Special infrastructure was also created to collect water from roofs and streets, which feeds the underground retention tanks. The filtered rainwater is used to water the urban vegetation and is also pumped to hydrophytic systems where plants take care of its treatment. The Kingston Renewal provides annual storage of approximately 4,000 cubic metres of water.
Warrnambool (Australia)
Here, a comprehensive system was created to collect water from the housing estate’s roofs into an above-ground retention tank. In order to do this, a separate rainwater drainage system was run from each house, which then transports the water to the tank. The collected rainwater undergoes a treatment process in which it is given the quality of drinking water. Thanks to the measures taken in Warrnambool, more than 16 million litres of water are collected annually. This impressive amount is the equivalent of what the local population drinks in a year.
Houtan Park (Shanghai)
It is an example of a comprehensive use of space, not limited to the use of rainwater, but extending its properties to purify the air, filtering water from the surrounding river, protecting against floods and providing a place for leisure and recreation. Houtan Park was developed as part of the 2010 World Expo project on a brownfield site adjacent to the polluted Huangpu River. The park area has been arranged in a terraced and cascading manner, with lush vegetation developing on each floor, which filters river water and rainwater in a completely natural way, purifying and aerating it. The water thus collected is used in the Expo Park below.
Rainwater use in low developed coutries
While there are many examples of rainwater harvesting in rich countries, it is still not popular in low-industrialised countries. One reason for this is the very low rainfall in regions such as Central Asia, India and Africa. A second obstacle is the lack of funds to build retention tanks or implement systems to collect water from the roofs. Therefore, in underdeveloped countries, rainwater is used on a small scale, people collect it for their own use in domestic tanks and use it in everyday activities such as washing, washing and even personal hygiene. The water collected in this way is also used in local agriculture to irrigate fields.
