designing resilient community parks
With the increase in impervious surfaces and more frequent intense rain events due to climate change, the need to address complex flood related issues is becoming even more important. By deploying an understanding of topography, hydrology, and ecology to create systems that divert, absorb, or capture water, landscape architects have the potential to create multi-layered solutions that can mitigate flood risk and improve ecological and human health conditions.
One such example of how TBG is addressing complex flood issues is Airline Community Park – a 120-acre community park in Baton Rouge, Louisiana – which serves the immediate southeastern region of East Baton Rouge Parish. With the goal of transforming a park that was 90% flooded during the 2016 rains into a system that can inundate and thrive in those conditions, TBG is embarking on a master plan that emphasizes green infrastructure practices and design for resiliency and sustainability.
Hydrology
Contextually, the park is bordered by Ward Creek to the west and Bayou Manchac to the south. Typcial water flow occurs through run-off on the site to Ward Creek and then leaves the area through Bayou Manchac eventually flowing into the Amite River (and on further to Lake Maurepas, Lake Ponchertrain, and the Gulf of Mexico). During large rain events – including events that do not occur within the watershed – water back floods from the Amite River into Bayou Manchac and up Ward Creek. This backflooding of water is what caused the site to be 90% under water during the 2016 flood, shown below. This high level of flooding did not occur until seven days after the event as the contents of the adjacent watersheds began to back up into the site. The sheer volume of water coming back into the watershed was slow to recede due to the railroad bridge and roads crossing Bayou Manchac.
Aerial photographs from the 2016 flood event
CSRS helped our team in discovering this backflooding as depicted in the above exhibits for a 100-year event.
Day 1 (top left) – flooding of the water ways occurs in low lying areas; localized flooding that impacts the site watershed
Day 5 (top right) – flooding recedes and heads down stream
Day 7 (bottom left) – backflooding occurs and is substantially larger than the local flooding event
Day 13 (bottom right) – waters recede almost to their normal condition
Topography & Habitat
Preserving the large live oak tree canopy and utilizing the areas to provide shade and places of respite for the park’s guests is another critical project goal. The large existing natural area is bisected by a manicured and maintained lawn space. This creates an opportunity to connect the two sides of the site and will provide one continuous habitat environment for flora and fauna. Reforestation and restoration will not only create new habitats and living systems, but will strengthen Bayou Manchac as a riparian corridor, increasing the aviary population in the region. During our analysis process, an invasive apple snail was found on site. Our team is working with BREC to ensure that there are specific management and maintenance strategies in place prior to any water bodies being built so that the invasive apple snail does not damage the ecosystem.
There are several high points on the site that have remained as drainage points during flooding events. These high points have great opportunities for program activities outside the flooding zone.
Topographical features
Elevation analysis
The low points, alternatively, can help act as catch-basins and environmental education opportunities for flooding events. There is a former bayou meander that could be extended and developed to help with flood events and the impacts of water flow. On one of the high points, BREC received a grant for a FEMA safehouse that will also double as a recreation center – adding additional program items activating the park, while using the natural elements to locate it appropriately.
Hydrological synthesis diagram
Flood-resilient design extends beyond necessity. It can provide opportunities to improve biodiversity, locate programming as it relates to topography and create artful destination landscapes that divert, absorb, or capture water. As we continue to create the Airline Community Park master plan, we will foster its long-term environmental viability to sustain various rain events while creating a unique world class park for the community.
Stay tuned for the next update from Airline Community Park in the coming weeks!