It's actually not uncommon to have laws that restrict gathering rain water in many places. Lots of US states do as well. If water is collected locally on a mass scale, it messes with water tables/rivers/lakes/etc.
Forbidding it when a place doesnt have otherwise dependable water infastructure is inhuman however.
A graphic representation of the unfair restrictions is that while many Jewish settlements have swimming pools, Palestinians in “Area C” of the West Bank are not allowed cisterns for collecting rainwater.