Water is a critical issue in Afghanistan. The country receives less than 300 millimetres of rain each year and shares all its river basins with neighbouring countries. Twenty-three years of conflict have left its water infrastructure system shattered. And drought over the last five years aggravated the situation. Today, only 17 per cent of the rural population and 38 per cent of the urban population have access to a basic water supply system, one of the lowest levels of access in the world.
Although bad, the situation is not necessarily dire. With a per capita water use of 1,700 cubic metres, and a national per capita water resource of 3,200 cubic metres, the Afghans have a comfortable amount of water, if managed properly.
And it could be managed both easily and in a sustainable manner, at least in part, by repairing the existing karez water system. The gravity-based karez system exploits groundwater without any need for mechanical devices. A vertical well is dug to tap into groundwater some 30 metres underground. Instead of bringing the water to the surface at the site of the well, a horizontal tunnel with a gentle downwards slope brings the water to the surface several kilometres (km) away. Through a series of such tunnel systems, large areas of land can be supplied with water.
The karez system originated some 3,000 years ago in ancient Persia, where it is called qanat, and expanded east to China and west to North Africa, Cyprus, the Canary Islands and even Spain. Until late 1980s, some 170,000 hectares (ha) in Afghanistan were irrigated by karez, with 10 provinces depending on the system for more than 40 per cent of their irrigation.
But after years of conflict, the karez are not in good shape. Most need extensive repairs. Surface irrigation channels and shallow wells tapping natural springs and groundwater as well as more modern irrigation canals are also badly damaged. The result is that the irrigated area of Afghanistan is now only half what it was in 1980.
And with upwards of one million people returning to Afghanistan since March this year, there is added pressure for water. The sudden increase in demand, declining groundwater and collapse of institutional structures are placing enormous strain on Afghanistan's water management systems.
But water management cannot be addressed as an emergency measure. It needs vision and strategy at a national level. Investment in water management should create employment, improve water availability and food security, not damage the country's ecosystems, and provide equitable water sharing. All these are factors built into the karez.
The karez system is also intrinsically sustainable, adjusting itself to the level of available groundwater. If the level drops because of lower rainfalls, then the amount of water flowing through the karez also drops. In this way, vital aquifers are not depleted.
The entire karez system could be rejuvenated for about us $20 million