First, I think that this movie is one that is still ahead of it's time. For me, it is work of pure genius.
I am really drawn to the lack of resources of food and water as something that is pretty certain in the future. Particularly the lack of clean water. That is already happening here in the USA.
There are towns here in MO for example that has "contaminated" water and people still live there. They have to buy bottled water to cook and drink with.
You can go look at Russia and the people that live in the aftermath of Chernobyl in the "exclusion zone". The live and eat radioactivity. Who knows what the fallout from that is going to be? (pun intended

)
Then huge areas out west with water restrictions for many yrs now.
To be honest, REAL CLEAN water no longer exists for use by people. Now maybe somewhere up in the mountains but even then it is no longer pure, really.
I know you have springs and wells but I don't think they are "pure" anymore either.