Often, a comprehensive reservoir design provides for sediment storage in addition to flood water storage. Provision of sediment storage helps ensure that the proposed flood water storage is available for a minimum number of years. Nearly all major reservoirs and NRCS flood water retarding structures have sediment storage provisions. In analyzing the storage proposed, only the storage provided for flood water should be considered.

The adequacy of the proposed storage should be checked by routing the hydrograph through the proposed reservoir. Consider the following:

The factors of the hydrograph, storage, and outlet relations should be considered simultaneously using a routing process. Several flood routing techniques are useful for department analysis. Chapter 4 discusses .