An Iranian plan to irrigate its desert cities using water from the Caspian has provoked concern in Russia and has raised questions about Iranian compliance with the Caspian community's self-proclaimed emphasis on equitable usage. The $1.5 billion project was announced by President Mahmoud Ahmadinejad in the northern city of Sari on 16 April. It would involve a desalination plant on the Caspian coast, from which the water would be pumped 140km south to the city of Semnan, which lies east of Tehran.

Around 200 million cubic metres of water would be transferred through the 500km pipeline each year under the first phase – subsequent phases will expand the volume of water supplied to inland cities to 500mcm. Officially, the other Caspian governments have yet to comment – all use desalination plants of their own, albeit on a smaller scale than Iran's new project. However, some Russian commentators drew parallels with the Aral Sea in Central Asia, where decades of Soviet over-irrigation led to an environmental catastrophe and a drastic shrinking of the size of the sea.

The Caspian's ecosystem is already widely recognised as being extremely fragile, and a decline in the water volume – made worse by declining inflows from the Volga river – could have serious effects across the Caspian. This is especially significant given Tehran's repeated insistence that any activity (ie, a Trans-Caspian Pipeline) that could damage the Caspian ecosystem must only be taken with the consent of all five littoral states. If a Caspian summit does get under way this year (see page 8), the other leaders may have some tough questions for Ahmadinejad.

For more news and expert analysis about Iran, please see Iran Strategic Focus.

For more news and expert analysis about the Caspian region, please see Caspian Focus.

© 2012 Menas Associates