Water crisis is coming and it may not be limited to the less developed areas or far off arid regions. The water crisis which was until now was troubling the remote, undeveloped areas is pushing big cities to the brink. Conditions seen in Barcelona and many Australian cities present a picture of want we can expect in the near future.
In the summer of 2006 the Australian drought was described as being the worst in a thousand years. Reservoirs in Sydney, which are sources for many neighboring town & cities, were well below their normal levels and the inflows were just 5% of the normal. As the drought conditions are spreading to other places scientists believe that the drought in the Murray-Darling could become permanent.
Spanish state of Catalonia is also dealing with a water crisis. As the residents await the completion of a new desalination plant the reservoirs have dropped to 20% of their capacity. The reservoir can provide water only till October while the plant would be ready only by May 2009 thus forcing the state government to ship water from the neighboring French city of Marseilles. Heeding to the grave predictions that even a good spell of rain wouldn’t end the drought people of Barcelona are changing their lifestyles to conserve water.
A recent New York Times article looks at the global expanse of the water crisis.
Obviously the biggest single cause of the water crisis is the fluctuation in weather patterns leading to decrease in rainfall throughout the world. El Nino is greatly responsible for the drought conditions in Australia. Some scientists also blame the rising pollution levels as a possible reason for the decreasing rainfall. Weather patterns and periodic weather processes cannot be directly controlled but there are factors which are significantly influenced by our actions.
Underground water, lakes and rivers are the most common and crucial sources of water for cities around the world. In addition to direct rainfall they also get water from runoff and seepage. During rain shower water percolates into the soil where it might join the water table or move laterally towards a nearby lake or river, this is called runoff water. For the water to percolate down the soil must be permeable, the soil structure also acts as a sieve and filters out most impurities from this water.
As the cities around the world witness a population boom the expansion of concrete jungles is inevitable. Vast areas covered by pavements and roads cover the permeable soil which otherwise would have allowed the rainwater to percolate down. Cities face this problem even if they receive a substantial amount of rainfall because all the rainwater flows over these pavements and into the drains, thus making it useless. Even if the water from the drains is taken to treatment plants millions of dollars is spent to make it potable.
The cities which lack a good drainage system face the added risk of floods as was seen in Mumbai, India in July 2005. On receiving a record breaking 944mm rain in 24 hours Mumbai’s outdated drainage system clogged resulting in massive flooding.
Infrastructure expansion cannot be and shouldn’t be stopped thus we must look for ways to deal with the water crisis without adversely affecting our economic development. The simplest of all the solutions is Rainwater Harvesting. It is simple process of collecting the rainwater and is highly economical. Modest changes in the construction of buildings can create provisions for collecting rainwater.
Giving gentle slope to the roof to allow accumulation of water during rains at the lower corners of the roof from where it could be collected for domestic use. The rainwater is one of the purest form of natural water still it some microbes or dirt can pollute it as it flows over the surfaces hence it shouldn’t be used for drinking without proper treatment. If the collected water is allowed to stand for few hours most of the suspended particles would settle down resulting in a clearer and relatively pure water. If more cleaner water is desired then pallets of alum (for sedimentation) and chlorine (for disinfection) can be used; alum and chlorine tablets are commercially available.
Furthermore, the rainwater can be used for bathing, washing utensils and cars, watering the gardens. Rainwater can be used instantly for such purposes and it helps in reducing the burden and cost of operation of the treatment plants. If the collected water is not to be used for any domestic purposes then it could be sprinkled over the farms. The plants will take up the water required for growth and the rest will percolate to join the water table for later use.
It is possible to tackle our water problems by adopting simple methods of collection and effective use of rainwater. A little innovation and common sense would help us fight the water scarcity that our world faces today.