In-ground boxes were used; however, they were overgrown with grass. We finally managed to locate all 7 zone valves and the master valve. It only took about 10 hours, but we found them all, and cleaned them out. That was 80% of the time spent on this project. Lesson learned...keep those valve cover areas weedeated out every week!! The root cause appears to be sand from our well. We get this really fine sand from the Paluxy Sands in our well water. We had severe sand issues for a while after first digging the well, and apparently it was enough to cause problems in the irrigation system 3 years later! The sand got into the diaphragms in the valves and blocked the little pin holes that allow the valves to close. That, combined with lowering the water pressure slightly, would not allow the valves to close. Thus, multiple stations would be running at the same time. Everything is working better than before now, thank goodness! I found a great site for electrical troubleshooting that helped a lot (link below); that helped narrow down the possibilities right off the bat. Here is a link that might be useful: Sprinkler System Electrical Troubleshooting

Hi Marti, this is the info that came with some of our hoses. The manufacturer recommends spacing between soaker hoses based on soil type. On sandy soils the hose should be 1 to 1.5 feet apart. On loam soils, hose spacing should be 1.5 to 2 feet apart. And on clay soils spacing should be 2 to 3 feet apart. If you have a heavy soil, which is hard to dig, then use the 2 to 3 feet spacing as you wind or spiral the hosing in and around the plants to be watered. The manufacturer also indicates that the hose should be operated at low pressure and flow  10 to 30 pounds per square inch (PSI). However, this requires the addition of a pressure regulator at the supply end of the hose. Rather than attaching a pressure regulator, I suggest just barely opening the hose bib to obtain the smallest amount of water flow through the hose. Although not scientific, my tests have indicated that by just opening the hose bib slightly, the flow rate of water out the hose is about .6 gallons per foot-of-hose per hour. So, a 50 foot soaker hose would apply about 30 gallons of water per hour. Comparing this to the output of one gallon drip emitters on standard 3-foot spacings, the soaker hose applies double the amount of water over the same given time. The time needed to water with a soaker hose will depend in great part on the type of plants being watered. Trees require the longest soaking since their roots can extend down 3 feet. Small garden plants and ground covers need the shortest soaking since their roots extend down only 12 to 18 inches. The object is to allow the water to penetrate down to the rooting depth. When laying out the hose over the area to be watered, remember to watch spacing. When watering trees, start the soaker hose a few feet from the trunk. Spiral the hose out several feet beyond the edge of the branches. This will allow watering of a substantial portion of the roots. When watering shrub or ground cover beds, snake the hose through the area, extending the hose just a foot or so beyond the outermost branches. Turn the hose on and allow the water to run 30 to 60 minutes, then check the depth of wetting. You can do this by using a metal soil probe. A 3-foot piece of metal re-bar or a thick wooden dowel will work. The rod can be pushed through moist soil, but stops when dry soil is encountered. Measure the depth of wetting and adjust the watering time of the soaker hose accordingly. It may take several hours to properly water a tree. A final suggestion. Rather than run your soaker hose for a continuous time period, try running it in cycles  one hour on and one hour off until the desired depth of wetting is reached. This will further slow the rate of application and increase absorption.

Well if you are not good at this get a pro who installs these systems , maybe the person before did not need to have what you want.

@formulaross20 is correct, changing irrigation types does not change the backflow prevention requirements. You have an AVB which is code in many states for backflow. If you were to go to a centralized backflow, a PVB or RPZ would typically be sufficient. Both options are more expensive than the AVB zone valve and this is why most installers use them when they can. Stick with what you have or if you want to hide the valves, put in a PVB, and use an inline jar type valve. What I used in my yard: PVB:https://www.sprinklerwarehouse.com/pvb-assembly-fe765-100 Inline Valve: https://www.sprinklerwarehouse.com/irritrol-sprinkler-irrigation-valve-2500tf