Marne Creek Flood Mitigation	Platte Eastside Drainage Project	Tea Storm Sewer Project	Willow Ridge Drainage Study

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Tea Storm Sewer Improvements Project

Tea, South Dakota

The small but rapidly growing community of Tea, South Dakota, lies just southwest of Sioux Falls. Eisenbraun and Associates was selected to address the city’s insufficient capacity to handle storm water that caused it to experience regular flooding. The design team on this project faced relatively flat topography, highly variable soil conditions, locally high water tables, and irregular building elevations within the community. Challenges also included identification of potential and historical drainage problem areas, placing storm sewer inlets and pipes in the most effective and cost efficient locations, and predicting changes in runoff potential due to development within and adjacent to the community. The final storm sewer design would be the culmination of community input and engineering innovation to provide an acceptable solution to the Tea drainage problem. Eisenbraun and Associates provided the project design, construction staking, and project administration for the project. Throughout the process of project planning and design, informal workshops were implemented by the E/A Design Team to solicit input from the Tea City Council that would facilitate the attainment of key project objectives. The key objectives included providing a design that could be constructed within the projected budget, providing drainage relief for all property within the city, and ensuring timely project construction completion.

Storm water flows generating from two separate residential developments adjacent to the north edge of Tea are directed to a common storm water detention pond as part of the overall storm water management plan. The property within the boundaries of the detention pond is privately owned by the adjacent developers and contains both natural and artificial wetlands. The E/A design team spearheaded a cooperative effort with the Army Corps of Engineers (COE) and the individual developer’s engineers to design a storm water detention pond that complied with COE 404 requirements and satisfactorily met the needs of the City. During the course of this project, the E/A project team coordinated with the SD-DOT, the Army Corps of Engineers, the County Commission, contractors, developers, utility companies, residents of Tea, and the Tea City Council to provide planning, design, administration, and logistical expertise in an effective and professional manner for this $2.1 million storm sewer/street improvement project. The residents of Tea now have comprehensive drainage relief via 8,800 feet of reinforced concrete pipe in sizes ranging from 15 to 60 inches in diameter. In addition, the final construction contract amount was 19 percent under budget.