When I moved to the area I live in now, the water pressure was what I would class as fierce. That was over forty years ago and since then there has been a steady decline in the pressure, which I have put down to an increase in the population of the area as well as a policy of the water companies to maybe, prevent leaks. The pressure is still sufficient as long as it doesn't get any less. Everything water reliant works o.k. as far as I am concerned.
Rainfall has always been enough to keep my lawn in reasonable nick. Lots of sunshine here too which has resulted in me calling it God's Little Acre. That in turn has resulted in the increase in population which has resulted in a reduction in water pressure. (Simples).