The level of groundwater resources in Semnan Province on average drops annually by 60 centimeters posing an existential threat to the water resources of the province, managing director of the Regional Water Company said.
“Semnan is among the regions with the least amount of rainfall and over 95% of the province spans the central desert, which shows the dire water condition,” Iraj Heydarian was quoted as saying by Mehr News Agency.
“More than 60% of the urban population lives in the cities of Semnan and Shahroud, and as a result we see the highest water consumption in the two cities,” the official noted.
Semnan is to the east of Tehran Province. More than 43,000 farmers earn their living from tilling the soil stretching over 198,000 hectares. They produce 1.5 million tons of farm products p.a., namely grapes, pistachio, apricot, pomegranate, olives, garlic and pepper.
“It is indeed regrettable that huge withdrawals from groundwater resources continue unabated. Moreover, the amount of precipitation is much lower than the national average and the rate of water evaporation is high. Water is being supplied from external sources,” the governor said.
“If new water resources are not defined for the province, we will face serious problems in future,” Alireza Ashnagar said.
One solution, though highly controversial, is the ambitious plan to divert water from the Caspian Sea to the Central Plateau albeit to the chagrin of prominent environmentalists, conservationists and climate change activists.
The government, however, insists that diverting water from the Caspian Sea in the north to Semnan Province is now the “best available option to fight drought in the central plateau. The overall plan is to siphon 200 million cubic meters of seawater a year to the desert region.
Other strategies, namely rainwater harvesting, judicious water use (especially in the agro sector), promoting advanced irrigation techniques and recycling wastewater have been implemented. However, residents still suffer from water shortages and almost 500 million cubic meters of water is wasted annually in the industrial and farming sectors in the province.
Environmentalists Opposed
Water and environmental experts have voiced their strong opposition to the water diversion plan in more ways than one. Their argument is that transfer of desalinated water from the Caspian Sea will increase the sea’s salinity and destroy the marine ecosystems.
In articles published as far as in 2016, most asked one simple question: Is pumping desalinized water from hundreds of kilometers away a sustainable way to support dehydrated mega-cities and parched farmlands? The experts say no.
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 water transfer plan will be implemented with technology known as reverse osmosis that will need a large number of carbon filters that need to be changed frequently producing huge volumes of waste.
The other contentious issue is the path through which the pipeline would reach Semnan. A 200-km pipeline has been considered to that will have to pass cross the Alborz Mountians and pass through the world famous Hyrcanian Forest, requiring the felling of trees in the ecologically-rich but vulnerable woodlands.
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 acidification of the donor basins, damage to the ecological environment of the donor basins and both sides of the conveying channel system and increase in water consumption in the recipient basins.
