The experience in other countries like China shows that water diversion schemes normally impose prohibitive costs and their (ecological and social) harm far outweigh the anticipated help. So these are not necessarily optimal solutions to fight water paucity, in particular in the long term
For example, work on China’s South-North water transfer project (the biggest inter-basin transfer scheme in the world), started in 2002 and ended after 12 years, Financial Tribune reported.
It is considered controversial not only for its high cost ($62 billion) and displacement of people, but also due to environmental harm like massive destruction of pastures and forests. Strangely, a similar strategy has been embraced by our policy and decision makers to transfer water from the Oman Sea to the eastern regions like Kerman.
On the other hand, curbing demand is less costly, faster and in the long run more effective than increasing supply via water transfer initiatives, one of which is the plan to divert water from the Caspian Sea to arid regions in Semnan Province projected to cost at least $200 million. The plan involves siphoning 100 million cubic meters of water out of the sea a year that would hardly meet 15% of region’s water demand.
Sea water diversion schemes have never been sustainable anywhere in the world as their long-term ecological impacts are massive. Moreover, so long as recycled water is available and can replace diverted water, there should be no need to harm the ecosystem.
In addition, huge amounts of water can be saved by reducing leaks in the distribution networks to commercial, residential and public premises.
If (and when) necessary steps -- expanding wastewater plants and updating farming practices are in place, water-stressed regions like Semnan can be self-reliant without the need to transfer water from long distances.
For the past fifteen years, water demand management has been in the limelight as a key issue of to underpin sustainable development in the Mediterranean regions.
Nevertheless, officials in Tehran insist on building dams (instead of rehabilitating infrastructure eroded by use and seepage) and transferring water to far flung destinations where a large proportion of water goes to waste due to outdated farming practices and lack of wastewater treatment facilities.
According to the Food and Agriculture Organization of the United Nations and the World Bank, agricultural sector accounts for 70% of all global freshwater withdrawals. As the global population increases, agriculture will exert pressure on dwindling water resources unless new policies and strategies are pursued.
Setting up rainwater recovery systems, improving efficiency of irrigation methods, revising crop management and proper intervals between harvesting and planting have been suggested as practical methods to consume the precious source prudently.
Rainwater is usable after treatment, especially for showers, washing machines, and toilets. In France, such recovery systems can reduce domestic use by 30% depending on the region
In the industrial sector, transferring water-intensive industries to coastal areas, modifying equipment, changing technologies and on-site water recycling and reuse should be given higher priority than pipe laying.
Nearly 20 million Mediterranean people have no direct access to drinking water, especially in the rural areas of the south and east.
Resources are already overexploited in some places and water demand is set to rise substantially as the population increases in the south and east and the economy grows through tourism, industry and irrigated agriculture.
The truth is that (now more than ever before) water needs to be used sensibly. Resources must be used frugally in ways that meet the requirements of people, economic growth, and the environment now and the generations to come. Efficient and effective management of (limited) resources is among practical approaches to bring secure and sustainable water to all parts of Iran.