leaky levee
n.— «The design would include so-called “leaky levees,” an idea that features culverts at strategic locations, allowing Gulf of Mexico tides to move in and out of the northern reaches of the estuaries, maintaining hydrology critical to sustaining plant, fish and wildlife.» —“Nagin sees plot against blacks in slow rebuilding” by Dennis Persica Times-Picayune (New Orleans, Louisiana) Mar. 18, 2007. (source: Double-Tongued Dictionary)