A thesaurus is an organized list of vocabulary in one or- morerndisciplines structured in such a way that synonymous, broade,rnnarrower and related terms are presented in alphabeticalrnsequence. It is used to guide the user as to which descriptorrnto select f r om the indexing language for indexing or gettingÂ·rnaccess into a database to retrieve relevant information.rnThe objective of this work is to construct a computer- basedrnAmharic Thesaurus in water technology. Considering thernresponsibilities entrusted upon and the amount of informationrngenerated by the Water Resources Commission of Ethiopia, thisrnthesaurus is of immense importance in collecting, analyzingrnand indexing water related documents written in Amharic, whichrnare hitherto not properly processed, catalogued and indexedrnfor easy r etrieval .rnAfter extensive discussions with experts in the field andrnproject site visits, an English-Amharic dictionary holdingrnsome 2000 terms was created for use in defining terms andrnidentifying interrelationships among the terms. Then,rnrelationships among these terms entered into the thesaurus wasrnestablished according to the principles of thesaurusrnconstruction. Finally, a sample database of the indexinglanguage is formed using CDS / ISIS, THES. PAS Programrntranslated into Amharic.rnThe work is not fully complete. Further effort is needed tornautomate the thesaurus entirely and to include local termsrnthat are not yet fully covered. The task of facilitating therndevelopment of a multi-lingual system is also an area to bernseriously considered in the future.