You already answered your question.
She provide drinking water
The most likely reason the agricultural revolution caused a population increase was because “more and better food allowed people to be healthy and well fed”. When agricultural revolution took place it led to the increase in usage of pesticides fertilizer and other things. This led to the decrease in price of rice. Which led to the less death chances of people and leads to population increases.
It looked like Europe now. But It was calmer back then before WW1
