Abstract: The amount of water required for coal slurry transportation is a function of the coal properties and the magnitude of coal movement. The pipeline system characteristics and the method of slurry preparation also affects the overall water requirement of the system. In the present study methodologies are developed based on reported and modified coal slurry flow correlation equations to determine the quantity of water needed under various coal transport and flow conditions. Auxiliary water requirements including start-up and flushing water storage; related evaporation and seepage losses are also included. A computer program and several monographs are presented to provide a quantitative estimation of water requirements for fine to coarse coal slurry transport. The results are useful to the slurry pipeline design engineers in providing essential information for state and local water allocation policy determination. Funding information: The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior, Washington, D.C., as authorized by the Water Research and Development Act of 1978. Public Law 95-467.