Development of a decision support tool for planning and designing small earth dams

Abstract

This study examines the use and application of computer programs to support the decision making in planning and designing small earth dams. Design and construction of earth dams has been met with many challenges in planning with regards to making the right decisions in selecting a particular site for dam placement and the embankment design that will suit that chosen site – attributed to the numerous considerations, unclear and non-straightforward criteria currently existing in literature. This has produced a gap in decision making which extends the project timeline because of the need to reconstruct a whole decision path to follow and revisit literature each time one is to start a site feasibility study. The goal of this project was to develop a decision support tool for designing small earth dams to contribute to efficient planning of small multipurpose water storage systems and was accomplished by designing a flow chart for the decision support tool for dam site using the different documented criteria merged into one flow chart, and which includes studies conducted on water quality, water quantity and best site location. It has also been accomplished by building a user-friendly computer program, from the designed flow chart with equations and tables from the cited literature, using Microsoft Excel VBA and finally testing the tool to check its viability and response to the various user inputs. The results of this study show that the use of this computer program has made the procedure for site selection and embankment design a simple, accurate and efficient. It has given the user the ability to review multiple sites and select a more suitable one. From this study, it can be deduced that this program is able to work as a feasibility tool in the assessment of dam sites to help dam planners and designers. And in addition, a student or any user willing to make improvements on the program will have this document to act as a user manual. In conclusion, this program can be further improved by automating most of the processes using ArcGIS in developing elevation storage curves and running a software-based environmental and social impact assessment.