Subdivision Regulations can help communities address flooding risks exacerbated by new developments. Livingston has undertaken this approach to address one of the main risks to local resilience.
Flooding is a major concern in the Town of Livingston, the parish seat of Livingston Parish, approximately 25 miles east of Baton Rouge. The town is located at the convergence of four watersheds and frequently floods during severe weather events and routine rainfall events. Hurricane Gustav caused extensive flood damage as well as damages to structures and utilities from fallen trees throughout the town. Moreover, the town had trouble clearing debris from drainage ditches both in the town as well as the watersheds throughout the parish. This debris led to continued long-term flooding risk months after the actual storm. Compounding the risk of flooding is the town’s rapid population growth due to high quality of life, good schools, and close proximity to both Baton Rouge and New Orleans. Livingston Parish ranks among the top three fastest-growing parishes in the state. The town is seeing population growth rates of up to 2% per year and a 56% projected population increase from 1990-2015. Job growth in the area is projected to increase by 16 percent over the next 10 years. Subdivision and business growth along major corridors indicate these numbers are fairly accurate. Furthermore, the location of the Town of Livingston on the I-12 growth corridor, one of the fastest growing areas in the State of Louisiana, indicates a pressing need to address land use, watershed, and growth management issues in preparation for future need and development.
In response to future growth projections, the Town of Livingston adopted a Comprehensive Plan in 2010 to preserve the town’s integrity and way of life while guiding future growth and development through proper and flexible planning. The next step to realizing the goals laid out in this plan is to develop a set of accompanying codes and ordinances. Codifying these regulations provides clarity to residents and developers, while ensuring that the objectives of the plan are enacted. The development of Subdivision Regulations, particularly in a rapidly growing region, plays an important part in promoting a safe, desirable, and resilient community.
RESILIENCE PLANNING IN ACTION
The Town of Livingston’s new Subdivision Regulations lay out clear rules, procedures, and regulations that will ensure new development does not increase flood risks in the community. These measures are laid out in Section 24 of the new ordinance, Stormwater Drainage Requirements. In addition, the new ordinance clarifies the town’s requirements, facilitating the application process for residents, developers, and local government staff alike.
The natural flood risks in Livingston, being located at the convergence of 4 watersheds, are exacerbated by the rapid development that does not address those risks. The town’s new Subdivision Regulations will require major new developments to incorporate those concerns
- A Stormwater Drainage Impact study is required for all new developments over a certain size.
- New subdivision developments are required to demonstrate that their construction and on-site mitigation measures will prevent any changes to stormwater runoff affecting either upstream, downstream, or neighboring properties.
- These studies should take into account the predominant existing land use and future land use in project watershed using the latest data available. They should also describe the proposed development, soil types, vegetative cover, watershed slopes and provide an estimate of percent of impervious area for pre- and post- development conditions.
The design, layout, and specifications of public infrastructure play a major role in determining how stormwater will be channeled through a new subdivision, and affect flooding risks throughout the community. These subdivision regulations include such requirements and regulations for infrastructure. Specifically, elements of Section 24. Stormwater Drainage Requirements address stormwater management and flood protection.
An informed community is a major asset in promoting local resilience, as well as encouraging local investment. A clear ordinance provides valuable guidance, information, and transparency for current and potential residents, business owners, developers, and local government.
- Clear requirements for construction and development of new subdivisions are provided.
- Specifications are included for informing new landowners in areas with particular restrictions. For example, for any property within an open ditch subdivision, the following statement must be placed on the bill of sale of property: BUYER BEWARE: Installation of any subsurface drainage (other than a driveway culvert) is prohibited in this subdivision designed for open ditches.
Implementation of the Subdivision Regulations, in conjunction with the town’s Comprehensive Zoning Ordinance, and development of additional supporting plans and ordinances, including a Floodplain Management plan will help reduce local flooding risks and build resilience as Livingston continues to grow.