Tree Streets District Drainage Study
LOCATION: Johnson City, Tennessee
- Don Mauldin
- Flood Mitigation Study
- FEMA Data/Information
- HEC-HMS Modeling
- Watershed & Drainage Assessment
The Tree Streets District is a unique 285 acre mixed-use area of Johnson City, Tennessee. It is located west of the Central Business District and east of the campus of East Tennessee State University (ETSU). The southern boundary of the Tree Streets District is a ridge top, and most of the residential area is located on the slope below the top of the ridge facing northwest. The topography flattens near the north end of the district with the commercial and light industrial uses being on generally flat ground.
Storm drainage flows from the slope at the top of the ridge and is predominately conveyed by the existing streets. In the upper reaches of the area, there are no catch basins or pipes to collect the runoff. In the lower reaches, there are catch basins at intersections with connecting systems of pipe. The entire area drains to Brush Creek, which is located on the north side of State of Franklin Road. The stormwater passes under State of Franklin Road via a series of pipes which discharge to Brush Creek. The Tree Streets District has experienced periodic flooding due to:
- Aging Catch Basins
- Hydraulic Capacity Limits of Drains
- Limited Drainage System in the Upper Area
- Presence of Flap Gates on the Outfalls
- Bridge Overflows on Brush Creek
LDA was retained by the City to determine the specific causes of the flooding and to recommend mitigation to address the flooding issue. By managing and controlling flood runoff, flood risks to people and property can be reduced and travel on roadways previously inundated with stormwater will be safer. In the study, LDA collected available GIS, topographic, and FEMA data. LDA also conducted a field assessment of the watershed and drainage system, as well as prepared design flow computations using HEC-HMS. Additional tasks performed included preparing phased conceptual plans for the drainage infrastructure required to accommodate the design rainfall event and preparing a written report.
After submittal of the report, LDA was retained to design the first phase of the project. The first phase will involve the construction of a large diameter storm drain beneath State of Franklin Road and CSX railroad. The pipe will discharge to Brush Creek in the Founders Park area. The design is presently underway.Back to Projects