Downtown Drainage and Redevelopment

 LOCATION: Johnson City, Tennessee

 KEY PERSONNEL:

• Steve Bostic
• Don Mauldin

 DATES: 2005-2012

  COST: $30 Million

 PROJECT HIGHLIGHTS:

• Cost/Benefit Analysis
• Increased City Tax Revenue
• Greenway Improvements

The historic district in downtown Johnson City is prone to frequent flooding, which has hindered downtown redevelopment and diminished the value of downtown properties. The City retained LDA to develop a hydrology and hydraulics model of the watershed, and to study alternatives for mitigating flooding in the downtown area. The study consisted of the development of a SWMM model of the watershed and stormwater system, project cost estimates, a report presenting our recommendations, as well as additional alternatives.
Working closely with City staff and a Downtown Task Force organized for the project, LDA coordinated the development and approval of an overall downtown redevelopment and flood mitigation plan. The first phase of the plan consisted of removing approximately 700 feet of aged culvert on Brush Creek, replacing it with an open channel, and constructing a greenway park and amphitheater adjacent to the stream. In addition, the construction of rain gardens not only provided added stormwater filtration, but also enhanced the aesthetic appeal and water quality. LDA managed the design and permit negotiations for the project, as well as conducted a flood study to ensure that there would be no increase in flood levels due to the project. Future phases of the plan include park and public facility amenities, the construction of regional detention ponds, a bypass channel for King Creek, and other major drainage improvements.