Dave,

I would first check with the local water purveyor about what they would allow as far as booster pumps. I would program my watering during the non-peak periods when the pressure is higher. You would not want to use the booster during low pressure periods anyway. You could lower your street pressure further and affect your neighbors already low pressure. Talk to the water company and find out more why the pressure swings are so pronounced. I doubt they would let you come off a hydrant. Fire trucks have to provide their own booster pump trucks with that low of pressure and need to use the hydrant hookups. Aloha