As a City our hydrants are no more than 600' apart but we carry on each engine 800' of 5", As someone that use to lay hundreds of feet of two lines of 2 1/2 or 3" the 5" is the best firefighting invention that has come along in a long time
Our biggest supply hose is a 3" hose. We are mainly rural with dry hydrants. We actually only have 2 real hydrants in our area and very rarely get calls in that area.
All of the Eng Co's in our area carry at least 1,000' of 4" LDH and some of them carry 300-600' of 3" in their hosebeds as well. They also carry 25' of 4" in the front bumper and a shorter section of 4" LDH on both sides near the side intakes.
We have 2700 feet of 5 inch hose between the three pumpers - 1000, 1000, and 700 feet. Also short 25 to 50 foot sections in the compartments to hook to a hydrant or complete a stretch.
We carry 5" supply hose-1000 ' and 3" supply line-800' (if we need to extend hose lines) on our pumpers, our brush truck carries 3" supply hose-500' and our 2 tankers(first trucks that were bought- but used for water supply sometimes-especially at woods fires) carry 3 ' supply hose-amount unknown-but it's quite alot.