Zone with low water pressure?

If you have multiple zones on your lawn sprinkler system and one of them is under low pressure, this is a sign that you have pressure loss on that zone. Which is usually caused by a leak, if you found a saturated spot in that zone then you should dig up that area to locate the source of the leak and make the necessary repair. If a saturation area is not obvious then you will need to run that zone until you able to locate area of saturation. If after running the zone for a period of time there is still no obvious area of an leak then you will need to call an irrigation professional for further troubleshooting.