Use the National Diversified Sales 430 Green Plastic Spring Loaded Pop-Up Drainage Emitter w/ Elbow for 3" & 4" Pipes to safely discharge collected water away from structures, erosion-prone landscapes, and poor drainage areas. The Pop-Up Drainage Emitter with Elbow and Adapter connects to 3 in. & 4 in. single-wall corrugated pipes and 4 in. Sch. 40 pipe; remove the adapter to connect to 3 in. sewer and drain pipe and triple-wall pipe. When water pressure builds, the spring-loaded cap “pops up” as high as 1 in. to release water at up to 56 GPM. Cover closes automatically once the flow diminishes. Cap and cover is made of high-density polyethylene (HDPE) and the elbow is made of polyvinyl chloride (PVC).