Integration of Reservoir Volume Estimates into Water Resources Decision Making

Abstract

Engineers have long sought a tool that would improve the reliability of planning estimates for water storage volumes, especially under tight financial constraints. Three tributaries on a desert wadi in Jordan were investigated to learn about the possibility of groundwater artificial recharge using flood water retention structures. For each tributary, calculations were made without the assistance of surveying equipment and manpower to present to the authorities for a rapid decision to proceed with preliminary and final design of such water storage structures. Each tributary was visually observed and rough measurements taken to estimate lake volumes of dikes at different heights, ranging from 2 m to 10 m. The resulting volumes were calculated based on differing slopes of dike sides and effective lengths of profiles. These planning level estimates were presented to government decision makers and were subsequently compared to exact volume calculations from detailed topographical surveys. The percentage difference between planning and final volume calculations ranged from one to fifteen percent. In addition to the obvious conclusions that final volume calculations are more reliable, and that any planning level estimates must be done carefully, the following finding appears valid: under strict financial constraints that developing countries like Jordan are experiencing and under certain assumptions, planning level estimates can be used as an initial tool to estimate water storage volumes for small dikes with acceptable accuracy.