Backflow Prevention Devices are available in many shapes and sizes. Regardless of how large or small a device may be, they all serve the same purpose - to Prevent the Backflow of Contaminants into the Water Supply.
When a drop in main pressure occurs the potential for Backflow increases. City of Lakeland Construction Standards require these devices where the potential for Backflow exists.

The yellow posts around this backflow help to protect it from vehicle traffic.

Whenever possible an attempt is made to blend Backflow devices with landscaping.

When two devices are side by side generally each serves a different function. In this case, the four devices serve four different types of Water Service.
For questions about Backflow Prevention, Email Water Distribution.