First of all rain water we receive is in sufficient quantity.Our total need is 15% of the rain fall and if we are experiencing the shortage,it could be 1%.So,let us make storing arrangements by cleaning our rivers,by not allowing industries and municipalities to drain their sewerages.Let us rejuvenate all the filled up wells including in Mumbai.Thirdly dig bore wells in every housing society and send rain water into it.Start using bore well water for toilets.that saves 35% water bill of the society.
Inspite of this if sea water is to be desalined.do it where sea shore is there like Mumbai,Thane,Ratnagiri,Raigad,Sindhydurga districts.Use it in the closed by area and use the water saved there in the nearby water shortage areas.For example,water saved in Mumbai and Thane district can be used in nearby Nasik district.One need not desline water in Mumbai and send all the way to Gadchiroli.
Thirdly storage of sea water in Seas is 97.6% of total warer and you are goint to take hardly 0.5 to 1% of it for desalination.That would not affect the marine life at all.
A.P.Deshpande