SVC’s Surcharge Pit Grates are designed to handle excess surface water during extreme rainfall events or system overloads. Engineered for durability, performance, and safety, these grates prevent flooding and property damage by allowing stormwater to discharge directly to the surface when system capacity is exceeded.
The composition of a Surcharge Pit Grate consists of a galvanised steel forgebar grate, housed within a frame mounted on 300mm steel legs. They are typically used in WSUD developments such as rain gardens and wetlands, where there are low-lying areas prone to high levels of surface water during extreme weather events.
Typically installed above an overflow pit with the same clear opening size, the steel legs of the Surcharge Pit Grates are bolted down directly into the top of the pit wall, leaving clearance around the pit perimeter for high volumes of groundwater to be captured from the surface.
Similarly, when the underground drainage system is at full capacity, the elevated grate allows excess water to escape safely to the surface, preventing uncontrolled bursts in weaker parts of the system. It provides a controlled, visible point for emergency overflow, acting as an essential relief valve that protects the integrity of the entire drainage network.
