POOR design and maintenance contributed to levee failures during hurricane Katrina, an engineering panel told a US senate committee last week.
Investigators confirmed that levees failed at three points along two New Orleans canals even though water levels were half a metre or more below the tops of flood walls. Tests of two breaches showed that water had seeped through the underlying soil, undermining the structures, while the third breach was completely washed away in the flooding.
Water flowing over canals with I-shaped flood walls caused other levee failures by washing away the unprotected dirt that held the walls in…
