The lessons learned from this flood focus on the performance of the levees, governmental responses, the effects of flood fighting, change in stages due to levee breaches, flood modeling, and the lack of information dissemination to the public on the technical aspects of the flood. These lessons point out information gaps and the need for research in the areas of hydraulics and hydrology, meteorology, sediment transport and sedimentation, surface and ground-water interactions, water quality, and levees. The report presents a comprehensive summary of the 1993 flood as far as climate, hydrology, and hydraulics are concerned.

The rapid conversion of land to urban and suburban areas has profoundly altered how water flows during and following storm events, putting higher volumes of water and more pollutants into the nation's rivers, lakes, and estuaries. These changes have degraded water quality and habitat in virtually every urban stream system. The Clean Water Act regulatory framework for addressing sewage and industrial wastes is not well suited to the more difficult problem of stormwater discharges. This book calls for an entirely new permitting structure that would put authority and accountability for stormwater discharges at the municipal level. A number of additional actions, such as conserving natural areas, reducing hard surface cover (e.g., roads and parking lots), and retrofitting urban areas with features that hold and treat stormwater, are recommended.