I'm not sure if people realize this, but Iran suffered more than any other nation during WW2, including Poland, Japan, the Philippines, China, and that's saying something. As a neutral country, I believe they have had something like 25% fatality rate during the war.

This can be seen as the knock on effects from the downfall of the Persian and Ottoman empires, and to a greater extent the destruction of the Persian civilization as the leader in the Middle East, replaced by the British and later American empires.

Water depletion and failure is but one small symptom of their civilizational decline. These issues wouldn't have been circumvented by better planning, it was to some extent written in the sky that this would come to pass. How can they support the needed infrastructure spending and policy goals, not being a leading global power? For example, not being able to control inflows from neighboring countries, or have the USD or trading partners available to pay to import food.