Australia is the driest inhabited continent in the world. It also has been going through a prolonged period of drought called the ‘big dry' over the last several years. Ninety eight per cent of Australia's 20 million people live in cities, making it one of the highest urbanised nations. Vast chunks of the land in the inshore are dry and barren and so a majority of the cities are on the south-eastern coast. As it grapples with this scarcity there are lessons for India to be learnt.
This columnist, who had attended a conference on rainwater harvesting and water-sensitive urban design, again recollects the perfect platform that was for learning. Here are some lessons from the Land of Oz. While it is not clear as to whether climate change is the cause for the recent dramatic decline in Australia's rainfall, it is investing heavily in understanding and coping with climate change.
There has been an aggressive campaign to instal rainwater tanks in every house. The rural areas had already a tradition of people depending on rainwater tanks for all their needs. This is now sought to be brought into cities with subsidies as incentives. People are putting anywhere from 2,000 litres to 50,000 litre rainwater tanks and using it for non-potable purpose. The city of Brisbane is the leader with one in eight houses having a rainwater tank. A thriving industry has developed around the rainwater tanks and appurtenances like first flush and filters and even underground storage of different kinds are available off the shelf. Competition keeps prices down and technology is improving dramatically. India should also look at an incentive-based drive for rainwater harvesting in as many houses as possible.
Australian cities guzzle water. The single largest consumer is the landscape. A series of efforts are on to change to natural vegetation and move away from the water-intensive landscape. This has brought back bio-diversity of a kind never seen in cities. With the nation's unique bird and animal life, it is a pleasure to see the ring-tailed possum moving about amiably in parks in the cool evening hours and the kookaburra's laugh is now getting more common in many parts of the city.
Run-off from urban catchment carry pollution and end up in the beautiful beaches and oceans of Australia. A clean-up is under progress with beautiful walking trails along the coastline with information to the public as to the damage that can be caused by such litter as cigarette stubs on the roads of the city. Safe disposal of garbage is ensured with a view to avoid non-point sources of pollution.
Run-off from lawns which may carry fertilizers and pesticides are being managed through detention and retention systems. Water quality is now dramatically improving along the coastlines though much remains to be done.
While the big drought is on, it is equally true that when the rains come they bring copious water, causing flooding. Rainwater tanks, retention ponds which hold water and release it gradually and detention ponds which hold water for a long time all manage soil erosion and local flooding very well.
A great deal of investment is going in to understand and model the system well and then to put these into practice. With drip irrigation and mulching it is possible to send grey water into pebble beds to infiltrate the soil and cultivate plants and trees.
Wonderful habitats are being created around neighborhoods and in individual lots using grey water.
Community involvement and participation is seen as crucial to the sustainable management of water.