This dissertation presents a methodology for hydrologic modeling related to the design and operation of flood control detention basins. Prior to this document, a comprehensive, tractable methodology for detention basin hydrologic modeling did not exist. Furthermore, techniques used in the past have not always taken advantage of computer technology or recent advances in the field of hydrology. New and original methods are presented and are developed from personal experience, recent literature, and relevant courses at The University of Arizona. Chapters in this document include precipitation data analysis, detention basin stormwater inflow, detention basin sediment inflow, stored water losses through evaporation and infiltration, design issues, and operation under competing water use objectives. Engineering constraints and data availability are explicitly addressed throughout the methodology. The goal is to determine hydrologic variables for detention basin design such as active storage volume, spillway capacity, drain outlet capacity, and, additionally for some systems, the bypass channel capacity and side-weir threshold spill flow rate. In addition to providing an increased level of protection from flood damage, detention basins may also accommodate land use and water conservation objectives of urban society.