How can coastal parishes address coastal land loss, while promoting economic and cultural development?
Terrebonne identified eight specific natural hazards that can significantly impact its communities, including flooding, subsidence, coastal erosion, sea level rise, wind events (tornadoes, hurricanes), and storm surge. Currently, 90% of land in Terrebonne Parish is classified as environmentally sensitive, and the parish continually experiences significant land loss due to erosion and subsidence. As a result, future development options are limited. On the land that Terrebonne is able to develop, flood issues are worsened by extensive impervious surfaces, particularly the large number of homes built slab-on-grade. The paved surfaces occupy vital flood storage capacity. The parish estimates that 106 acres of land are currently under slab. With a 2,100 square foot house displacing 15,709 gallons of flood capacity, it is estimated that Terrebonne Parish is losing approximately 35.4 million gallons of flood capacity due to this type of home construction technique. Such data provides the impetus for Terrebonne to engage a new, more resilient approach to development.
Compelled by the destruction of its wetlands and resulting population migration, Terrebonne Parish, located on the southeastern coast of Louisiana, updated its Comprehensive Master Plan to incorporate resilience. Terrebonne Parish and its largest city, Houma, together form a consolidated city-parish government. The Parish completed its last city-parish comprehensive master plan in 2004. Over the next few years, a series of particularly destructive hurricanes hit the parish causing extensive damage. In the aftermath, residents of the southern bayou communities began to migrate to north Terrebonne Parish. The 2004 Comprehensive Plan soon became largely unusable due to the population shifting faster than anticipated causing strains on infrastructure and housing stock. These hurricanes also underscored the increased vulnerability to storms of communities in Terrebonne due to wetland loss. Wetlands act as a natural sponge that trap and slowly release flood water, as well as buffer coastal areas from storm surge.
Resilience Planning in Action
Vision 2030, which is an update of the 2004 Comprehensive Plan, adjusts recommendations made in the 2004 plan to reflect current settlement trends and environmental concerns. In addition, the 2012 plan adds 3 new sections to help the parish better address their environmental, social, and infrastructure needs. The plan acknowledges that settlement patterns will become more restricted due to coastal land loss and a focus on higher density development on higher, less vulnerable land. The plan proposes options to ensure that communities will maintain their cultural identity, conceding a changing landscape.
With over 90% of its land considered environmentally sensitive, or undevelopable, Terrebonne Parish sees increased vulnerability by loss of wetlands, swamps, and marshes due to erosion caused by salt water intrusion from the Gulf of Mexico. The plan addresses this issue as well as other environmental concerns, such as air quality, water quality, hazard mitigation, and the existing regulatory framework in which these issues can be addressed.
- Protect environmentally sensitive habitat areas through the creation of conservation zones, a Terrebonne Parish Nature Priorities report, and promotion of native plantings in public landscapes
- Protect wetlands for their stormwater management, flood control, and habitat value through greater coordination of Parish capital projects
- Implement stormwater management best practices and strengthen local codes to have local bodies of water meet or exceed national clean water standards
- Develop and implement a greenway plan and program that uses floodplains, drainage basins, retention ponds, and undeveloped land to connect neighborhoods with parks, schools, community destinations and downtown Houma
- Increase public access to the parish’s water resources for recreation, through planning and design of non-boating public access to waterfront
- Support high quality open space system through the identification of partners and dedicated funding
- Works to reduce storm damage from wind and water along the coastal plain and in those areas of the parish falling inside the 100 year flood plain through hazard mitigation activities
- Reduce ozone-related emissions by 20% by 2030 through an emissions audit and an Ozone Reduction Pilot Program
- Quantify and better understand the impacts of sea level rise on the parish by preparing a parish wide climate action plan
- Make parish buildings and operations models of resource and energy efficiency through the institution of a green procurement and building policy, overall energy efficiency efforts in parish buildings, and by pursuing the use of compressed natural gas in parish owned vehicles
The parish’s geographical location and topography make drainage of storm and rain water the most important infrastructure. In the 2012 capital improvement budget 52% of the budget was devoted to drainage and levee projects, while 22% went to bridge and road projects, 14% went to sewer improvements and 6% went to buildings.
- Upgrade and rehabilitate deteriorating infrastructure through implementing the parish sewer master plan, identifying funding to expand the community sewage system, working to eliminate the causes of sanitary sewer overflows, and by amending building codes to require apartment complexes to be constructed with grease traps
- Implement a GIS-based asset management system
- Support integration of drainage facilities into a public amenity network by implementing non-structural solutions to urban runoff treatment and management, and by incorporating an inter-connected system of run-off retention basins and drainage infrastructure into a public amenity
- Reduce solid waste stream by 25% by 2030 by seeking out best practices for solid waste recycling and disposal, and work with partners to develop regional strategies
The culture and economy of Terrebonne Parish is linked to its abundant natural resources. The plan identifies a number of actions to protect the cultural assets of Terrebonne through environmental protection, community identity building, and historic preservation.
- Promote sustainable growth and resilient development practices by incorporating element from the Louisiana Speaks Regional Plan and to actively participate in the development of the State’s Coastal Master Plan
- Balance development and preservation of natural resources and open space by implementing a gateway improvement plan, adopting design review standards in specific corridors and districts, preserve rural landscapes, encourage cluster and TND development types, and connect neighborhoods by sidewalks and bikeways
- Promote downtown Houma as the cultural center of Terrebonne Parish