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Flood forecasting, warning, and evacuation is dependent upon public education for its success. Communities will need a well-publicized emergency response plan. Public officials must know their roles. The media should know the potential hazards and responses. The residents of the flood- plain should know the hazards, responses, and their roles in the response. Education/Awareness Any floodplain management measure, preventive or corrective, will require community support and understanding if it is to be implemented. The local floodplain administrator can develop educational and informational programs to increase publiC awareness of floodplain management concepts. Public meefings, individual meetings with residents and property owners in the floodplain, brochures, and slide shows are some of the means available to distribute information to the community. Educational materials are available from FEMA. the CWCS, and in appropriate communities, from the Urban Drainage and Flood Control District. Corrective Measures (Structural Approaches) Flood Control Flood control projects protect specific areas from selected levels of flooding. Changes to the Basin Dams and Reservoirs Reservoirs can be constructed as single-purpose flood control dams, or they may serve multi~purpose uses including water supply storage. irrigation, hydroelectric power, and recreation. Most single.purpose flood control dams are designed for a high degree of protection and have normally dry or almost dry reservoir basins. Multi-purpose reservoirs will almost always have at least a little water in them since they serve other needs. Flood control reservoirs protect property downstream by providing capacity to store floodwaters in the event that such waters should suddenly accumu- late upstream of the dam. Rather than flowing uncontrolled through developed and inhabited areas the waters collect in the reservoir and are then released at a much lower and more controlled rate that minimizes damage to those developed areas. Although it may be possible for local governments to fund the construction of flood control dams, it is most likely that one of three Federal agencies will be involved in the construction of any such dams: the USSR, the Corps, or the SCS. Local cost sharing is a requirement of any Federally sponsored pro- ject. Depending on the specific Federal program the local responsibilities can include operation and maintenance costs, acquisition of necessary right- of-way, and freeing the Federal Government from any liability associated with the project. The cwes can assist local governments with the acquisition of land for the project. In addition, the CWCS can assist by putting local governments in touch with appropriate agencies. providing basic information, and suggesti')!!... questions which should be answered during the initial plan- ning process.~ Of the dams and reservoirs In Colorado that are either privately or publiCly owned, six are slngle.purpose and ten are multi-purpose flood control dams, The other dams have been designed primarily to provide storage for irriga. tion and municipal supply and essentially have no flood control pool. During a flood, many of these reservoirs could provide incidental flood protection if the water level in the reservoir had been drawn down. If, however, no opera- ting agreement exists which specifically provides for flood control measures, such protection cannot be relied upon. Detention and Retention Ponds Many communities have accomplished reduction of flood losses by slowing or storing stormwater runoff where It falls, These practices are applicable when watershed lands are developed into residential, commercial, or indus- trial uses. During a flood the increased runoff volumes are detained or tem- porarily held in ponds built on the development site. The stored waters are then released to the natural drainage course at historical rates (rates that were experienced prior to urbanization). The effect of these ponds is to lower the peak flow and spread it out over a longer time, A potential prOblem with detention facilities is that their use within a par- ticular basin can become Widespread without any consideration of the opera' tion of the entire basin as a system. 32