The Long-Term Hydraulic Efficiency of Green Infrastructure under Sea Level: Performance of Raingardens, Swales and Permeable Pavement in New Orleans

Greater New Orleans is surrounded by wetlands, the Mississippi River and two lakes. Excess rain can only be drained off with pumping systems or evaporation due to bowl-like shape of a large part city. As solution make climate adaptive, green infrastructure has been implemented that enable rainfall infiltration evapotranspiration stored water after Hurricane Katrina in 2005. The long-term efficiency infiltrating under sea level low permeable soils high groundwater tables often questioned. Therefore, research was conducted full-scale testing method measuring capacity 15 raingardens 6 pavements installed period 2011–2022. results show variation empty times for swales: 0.7 54 m/d. decreased saturation (ca 30% decrease time refilling storage volume) but all tested met guideline within 48 h. This contrast pavement: six locations had an higher than 10 inch/h (254 mm/h). are discussed multiple stakeholders participated ClimateCafe Orleans. Whether considered unacceptable depends on number factors, including its intended purpose, site specific characteristics most stakeholder expectations perceptions. designing, planning scheduling maintenance requirements stormwater managers carried out more confidence so will continue perform satisfactorily over design life mitigate effects heavy droughts future.