The backflow device on the side of my house is leaking

The device on the side of my house is leaking

This device is a pressure vacuum breaker (PVB) or backflow device, there could be a few different things going on here depending on the time of year. 

SPRING:
  1. If your sprinkler was winterized late in the season or improperly, the interior of your device may be broken, especially if water is coming out of the top or side of the device. If this is the case, your backflow will need to be repaired. 
  2. If  you are trying to start your sprinkler and water is coming out of the small stubs on the sides, you missed a step in the start-up process. You need a small screwdriver to turn each bleed screw so the slots are going the opposite direction as the pipe. 
  3. If you have just started your sprinkler, you may have turned the water on too quickly to allow the disc inside the backflow device to seal. Turn off the upper ball valve (the downstream one) then turn the water on in the basement SLOWLY. It is not unusual for the backflow to leak a little when you are first turning the water back on. 
  4. If the bleed screws are turned and the resealing attempt does not work, please contact the office for service.
FALL/WINTER:
  1. If your sprinkler has been winterized and you are seeing water dripping outside at this device, there is a problem with the shut off valve in the basement. It is either not off all the way, was turned past the stop point on the valve or it is failing to seal and needs to be replaced. 
  1. If your sprinkler was NOT winterized and the temperatures have dropped below freezeing, the interior of your device is broken. The system needs to be shut off ASAP, repaired and winterized properly.