"The survey highlights the fact that because agriculture accounts for the main share of water consumption, the limited resources cannot be managed efficiently until comprehensive studies are carried out to clearly understand how much water is used for producing certain crops. Under present conditions planting water-intensive crops (rice and wheat) will further diminish water resources and result in colossal damage," ISNA reported.

According to the report, an estimated 8 billion cubic meters of water was consumed in Iran to produce food,  namely wheat, in 2011 and the figure has been rising over the past decade. Serious concerns about water shortages have led to developing new concepts like virtual water, a universally accepted water saving method, which seemingly has not yet been taken seriously by policymakers in Tehran. 

It refers to the volume of freshwater used in manufactures and providing services. Based on this method when agro products are exported so is water, according to Financial Tribune.

Economic experts namely Ghulam Hussein Shafei, the chief of Iran Chamber of Commerce, Industries, Mines and Agriculture, believe that if a drought-stricken country like Iran imports one ton of wheat instead of producing it domestically, it can save about 1,200 cubic meters of irreplaceable water. The amount is 2,000 cubic meters for producing one ton of rice. 

In a water-scarce country the saved water can be used for other needs. If an exporting country is water-scarce it will actually have exported 1,200 cubic meters of virtual water, and as a result real water used to grow wheat will no longer be available for other needs.

According o Shafei, virtual water can help policy makers accurately assess how much water is needed for different purposes, based on which they can decide whether to produce a crop or a good domestically or import it.

In semi-arid and arid areas, knowing the virtual water value of commodities or services helps determine how best the scarce water can and should be managed.

Rising Consumption

In related news, IRNA quoted Mohammadreza Ahmadnasab, managing director of Tehran Province Water and Wastewater Company as saying that water consumption has risen by 5% in Tehran Province over the past six months compared to the same period last year.

"Residents in Tehran used 587 million cubic meters of water in the period, whereas the figure was 560 mcm in 2018," he said.

Water experts including Ahmadnasab assert that efforts to curb water consumption will be in vain without higher tariffs.

The government pays 25,000 rials (25 cents) for delivering a cubic meter of water whereas consumers pay 10,000 rilas (10 cents). This unhelpful subsidy, according to increasing number of experts and conservationists, explains why people take water for granted and have disregarded pleas for judicious consumption.  

Promoting the culture of consuming less and encouraging consumers to rethink their unsustainable ways are not and will not be as effective as revising the costly subsidy policies, he said.

"Close to 70 % of the water we take from rivers and groundwater goes into farming, about 10% is used in domestic applications and 20% is the share of industries." 

Globally, about 3600 km3 of freshwater is withdrawn for human use. Of this, roughly half is wasted due to evaporation, used for crops and transpiration from crops. 

The other half recharges groundwater or surface flows or is lost in unproductive evaporation. Up to 90% of the water withdrawn for domestic eventually flows into rivers and aquifers as wastewater. The wastewater from domestic sewage systems and industries should be treated before being dismissed.