The government is now confident that transferring water from the Caspian Sea to Semnan Province is the best alternative to help fight drought in the central plateau, the managing director of Iran Water and Power Resources Development Company said on Wednesday.
"Other proposals have been considered, yet there is no better choice than siphoning seawater and transferring it to Semnan for drinking and industrial purposes after desalination," ILNA also quoted Behrouz Moradi as saying.
Pilot plans are almost complete and comprehensive studies have been undertaken on marine ecosystem and dumping wastewater in northern regions.
"To help fight large-scale deforestation, the water will be transferred through the 160-km Neka-Rey oil pipeline, expanding from the north to central provinces," he added.
The proposed plan, which is almost finalized, involves siphoning 200 million cubic meters of seawater per year to the drought-hit province.
The venture, projected to cost $650 million, will be fully funded by the private sector, he said without elaboration, adding that it is expected to be completed in four years.
Referring to water shortage in Semnan, he noted that all illegal wells have been sealed in the province.
Other strategies, namely rainwater harvesting, judicious water use (especially in the agricultural sector), promoting advanced irrigation techniques, recycling wastewater, separating potable water from wastewater and implementing watershed plans have been implemented in the region. However, the residents are still suffering from water supply shortage that explains the Energy Ministry’s Caspian water transfer decision.
The transfer of desalinated water from Caspian Sea to the country's central plateau was first proposed by American experts in the 1960s. Since then, the plan has undergone changes and now the authorities are considering its implementation to supply water to Semnan.
Harming Marine Ecosystem
Naghmeh Mobarqaei, an expert on environmental studies at Shahid Beheshti University, has criticized the project for increasing "Caspian salinity and seriously harming marine ecosystems".
Desalination extracts mineral components from saline water, but it also produces large quantities of brine, possibly at temperatures above the ambient, which contains residues of pretreatment and cleaning chemicals.
Experts say brine is denser than seawater and therefore sinks to the bottom of a water body, directly harming the ecosystem.
The plan is to be implemented through a technology known as reverse osmosis that will need a large number of carbon filters.
"They need to change filters frequently, producing a huge volume of waste," Mobarqaei said.
Inter-Basin Transfer
According to the US National Library of Medicine National Institutes of Health, inter-basin transfer has both positive and negative impacts.
Inter-basin transfer is a term used to describe manmade conveyance schemes that move water from one river basin where it is available to another basin where water is less available, or could be utilized better for human development.
Its benefits include adding new basins for water-deficient areas, facilitating water cycle, improving meteorological conditions in the recipient basins, mitigating ecological water shortage, repairing the damaged ecological system and preserving the endangered wild fauna and flora.
However, the negative impacts include salinization and aridification of the donor basins, damage to the ecological environment of the donor basins and both sides of the conveying channel system and increase water consumption in the recipient basins.
