Backwater valves are designed to prevent backflow in numerous applications where easy service access for maintenance and cleaning is needed. Excellent for use in sanitary or storm sewer drainage systems to prevent waste back up due to inadequate drainage, for balancing multi-level ponds, aquaculture features or storage tank systems and many other applications. Spears® backwater valve has been engineered for improved function and easier service, especially in buried service with use of optional service-access extension available either preassembled with valve or as an add-on kit.