Push for water desalination plants. Israel has got the price down to about $0.50/1000 litres. The infrastructure might cost billions, but the technological costs would balance things out in a few years.
Israel might even have it cheaper now because it’s been about 10 years since that figure was cited.
The differences between Israel and Mexico are cultural and political. Israel is a Western democracy. There is some corruption to be sure but nowhere close to that in Mexico. There is criminal activity in Israel but the country is not dominated by the drug cartels.