Every drainage system needs a point of release to prevent back-up issues. Use the Pop-Up Drainage Emitter to discharge water away from structures, erosion-prone landscapes, and poor drainage areas. The Pop-Up Drainage Emitter with Elbow connects to 4 In. sewer and drain pipe, and the cover pops up to release water when pressure builds. Cover closes once flow diminishes and stays closed when not in use to prevent debris & rodents from entering and potentially clogging the drainage system. Weep hole at bottom of elbow drains out water left in pipes to prevent stagnation or freezing in cold weather. Flat profile design blends discreetly into the surrounding landscape. Cover is made of polyethylene; elbow is made of polyvinyl chloride. Pop-Up Drainage Emitter is a part of a complete drainage system that help with stormwater management. They work with pipes, catch basin drains, channel drains, trench drains, and drain grates to filter, capture, and convey excess water to drain pipes; the pipes carry the water downstream to discharge with a Pop-Up Emitter, or to percolate into the ground with a dry well or infiltration trench.