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Central Hamilton County Scenario Planning Study

Impressive land use... ...good example of how regional growth should occur.

When Volkswagen announced its $1 billion investment near Chattanooga in Hamilton County, Tennessee, regional planners realized the area was on the cusp of a significant growth surge. Add to that a proposed bridge over the Tennessee River that would create a new east-west transportation corridor, and the county was in for major changes to the environment, infrastructure and quality of life for area residents. By the year 2035, the area could see as many as 20,000 new homes, and more than 4,000 jobs created from new industrial and ancillary uses necessary to serve the expected growth. While the prospect of additional jobs and residents is exciting, planners were also instantly aware of the potential impact of this imminent and massive change, and that specific growth implications required serious consideration. GS&P was asked to organize a comprehensive, multi-dimensional growth planning study — the first of its kind in the region — to gather detailed data on land use, mobility, infrastructure, public service, and natural resources. The client charged GS&P with two main goals: to gain a comprehensive understanding of the full impact of growth over the next 25 years, and to include input from citizens on the resulting growth choices.

 

A Fresh Approach

 

Central Hamilton County is largely rural with the site of the Volkswagen plant situated on a former army munitions plant in a very sparse area. GS&P Senior Planner Kevin Tilbury says that there was more than excitement generated when the automaker’s announcement was made. “Though it was very good news, after the dust settled, the County took a step back and realized that this, combined with the proposed bridge over the river, could fundamentally transform this part of the county. Growth in the area had been guided by a comprehensive plan, and a series of small area plans that were developed long before the Volkswagen plant and the bridge were ever considered, so all of the plans needed review as part of the new study.”

GS&P conducted two sets of public workshops at key milestones in  the study, and listened carefully to citizens’ issues and concerns as they reviewed each scenario. Heading their list were concerns for traffic congestion, adequate infrastructure to support growth, and the protection of natural resources. Participants also wanted to understand the impact on schools, transportation, rural farmland and the associated costs in all areas.

Tilbury and team determined that a scenario planning approach would provide the best framework for the multi-dimensional study. By creating conceptual examples of various growth options and their potential effects, planners could visualize changes to the region spanning the next 25 years, and make decisions accordingly.

After hearing initial concerns from the client and local residents, the team presented three scenarios. First, the Current Trends scenario outlined the effects of continuing the current growth and development of low-density residential patterns and power centers, such as strip malls with national tenants or anchor stores like Walmart. Next, citizens looked at the Comprehensive and Area Plans scenario, which outlined policy recommendations and area plans over the past decade, including a shift toward mixed-use properties to preserve open space and rural land. Finally, participants were given the opportunity to view a completely new perspective on growth in the region via the compact-focused Alternative Growth scenario, which featured mixed-use and village-like residential areas with walkable neighborhoods clustered around schools, a town center and small stores.


Hamilton County in 25 years

Through careful analysis, GS&P made seven key revelations that painted a picture of the next quarter century. First, the study showed that shifting from less compact (Current Trends) to more compact (Alternative Growth) could have a significant impact. Even a modest shift in density — from an average of three dwelling units per acre to just over five — could result in 40 percent less land consumed and greater preservation of environmentally sensitive areas and farmlands; 40 percent less impervious surface; $49 million less in sanitary sewer and potable water supply infrastructure costs (and 28 percent less water consumed) fewer fire, rescue, and law enforcement facilities and personnel required to maintain adequate response times and service coverage; and shorter automobile trips resulting in greater potential for walking, bicycling and riding transit.

The impact on impervious surface alone was a major consideration. “Buildings, pavements, sidewalk, and parking lots all combine to form impervious surface, which collects solar heat and produces heat islands and stormwater runoff, which in turn creates flooding potential and discharges harmful pollutants,” explains Lindsay Puckett, GS&P planner and Central Hamilton team member. “Generally, the greater the amount of impervious surface, the greater the potential for stormwater flooding and harmful runoff.”

Stakeholders also learned about the impact on transportation. GS&P recommended placing homes and businesses closer together, which would result in shorter vehicular trips and less demand on infrastructure. Greater distances mean longer trips, more time spent driving and more traffic. Less driving equals less stress on roadways, and in turn, more walking and biking.

Another fundamental aspect of future planning was the importance of agency coordination during all phases of the planning process. According to Puckett, “Study findings demonstrate that the strategic placement of schools, parks, fire, rescue and law enforcement facilities significantly increases accessibility to the community. It reduces the total number of new facilities required, and underscores the need for coordination across agencies. Successful growth patterns would only be possible with everyone working together to plan effective strategies.”


A Red Flag

One of the study’s most significant findings was the lack of non-residential land uses within the study area, which indicated that future residents would need to travel elsewhere to meet daily needs such as working or shopping. This discovery became GS&P’s call to action to the client — failure to plan for non-residential land uses could have a negative impact on transportation and mobility.

“Current assumptions about growth in the study area place residential growth far ahead of employment growth,” says Puckett. “It is more advantageous to plan for these uses before they happen than try to mitigate them after the fact.” GS&P’s analysis demonstrated that coordinated land use and infrastructure decisions can result in significant capital cost savings. Specifically, Central Hamilton County could save over $30 million in sewer infrastructure costs through better development practices.

Personal versus shared space was also addressed. Through the scenarios, GS&P was able to show that well-conceived trade-offs between personal and shared space could be beneficial to all stakeholders. For example, more compact growth means smaller yards. However, devoting larger tracts of land to shared open space such as parks can provide abundant room for residents to relax, play and enjoy the outdoors.

At the conclusion of the study, GS&P recommended that a number of plans in the central portion of the county be revisited. Plans such as the proposed bridge over the Tennessee River would fundamentally change the growth prospects for Central Hamilton County. Municipal comprehensive and small area plans, long-range transportation plans, schools and facility plans, and water and sewer plans could also have a significant impact, and would need to be studied carefully before moving forward.


What’s Next?

As a direct result of GS&P’s outreach efforts, citizen stakeholders became informed decision-makers and rejected the status quo by endorsing a move toward thoughtful and coordinated decisions about growth, development and infrastructure investments in Central Hamilton County. GS&P further encouraged the client to continue the public dialogue so that questions and concerns can be addressed as they arise.

“The County is using these findings and some of the growth models to organize and develop a plan for the entire region,” says Tilbury. “Ultimately, this was an extremely successful collaboration between GS&P and the Hamilton County Regional Planning Agency. As a direct result, we have formed an ongoing relationship with the RPA, we’re currently working with them to update their Long Range Transportation Plan, and we will continue to serve the RPA as a trusted advisor for years to come.”

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Project Info

  • Client: Tennessee Department of Transportation, Chattanooga-Hamilton County Regional Planning Agency
  • Location: Chattanooga, Hamilton County, TN, USA
  • Market: Transportation
  • Services: Services
  • Team:
    • Cynthia Frear
    • Kevin W. Tilbury, AICP Project Professional
    • Lindsay Smith Puckett, AICP Assistant Planner
    • Mark A. Holloran, P.E. Project Manager
    • Marshall Elizer, Jr., P.E., PTOE Principal-in-Charge
    • Shawn E. Means
    • Tony H. Garcia
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