If you think that abstracting groundwater causing a dry borehole or dwindling stream is a problem, you can appreciate what a dilemma it is for a city as big as Jakarta, the capital of Indonesia. With a population of over 10 million (the largest city in the Southern Hemisphere) the people of Jakarta have been abstracting water out of the ground for years. But depleting groundwater reserves has serious consequences and Jakarta is now SINKING at one of the fastest rates in the world. It has sunk by 2.5 metres in the last 10 years! Half of the city is below sea level and researchers say that by 2050, most of Jakarta could be underwater.
Why is it sinking? Jakarta is situated on a very swampy coastal area and is crossed by 13 rivers. But it is human activity that is the problem. A lot of water is abstracted by the 10 million people for drinking and washing and this makes the city sink further into the ground.
The solution is a radical one. Indonesia’s President Joko Widodo has decided that the country should have a new capital city and move the Government and its offices to a new location. It is estimated that the move will take about 10 years to complete.
But the problem of abstracting groundwater is certainly not confined to large urban cities. Agricultural land and plantations are failing because we are taking too much water from the natural underground aquifers. Boreholes and wells have dried up, so deeper boreholes have been sunk. Eventually these will dry up and the process is repeated until there is no water left. The depleted aquifers can take hundreds of years to naturally replenish.
So rather like with climate change, we must act now by changing our thoughts and actions about using water. We must use water wisely and restrict the use of groundwater, instead using available surface water from streams, rivers and lagoons. For instance a hydro ram pump uses flowing water from a stream and delivers to where it is needed for domestic and agricultural use. It uses no electricity or fuel and so is completely carbon neutral. And most importantly, it has no effect on the groundwater levels and any unused water is returned to the watercourse.