Water security is a critical aspect of sustainable development, encompassing water quality, quantity, reliability, equitable access, and environmental sustainability. Domestic water security focuses on ensuring a sufficient and sustainable water supply for drinking, sanitation, and hygiene within households. However, many regions, including urban areas in developing countries like Ethiopia such as Debre Markos city, face challenges in achieving domestic water security. The aim of this study was to assess the domestic water security index of Debre Markos City. The development of a framework for the domestic water security index using Specific Measurable Attainable Relevant Time-bound and Driver Pressure State Impact Response criteria. After selecting relevant variables and indicators, an analytical hierarchy procedure multi-criteria decision-making process was used to incorporate expert opinions. This study considered four dimensions, eleven indicators, and fourteen variables to calculate the domestic water security index of Debre Markos. The proposed methodology was applied to available data for 2022–2023 to quantify the domestic water security index of Debre Markos City. The Analytical Hierarchy Procedure result based on expert opinions gives scores of 39.73, 31.16, 17.19, and 11.92 for water supply sanitation, hygiene, and water governance, respectively. This evaluation provides insights into the degree of water security in the city and can serve as a foundation for identifying problem areas and developing plans to improve domestic water security. By incorporating the weighted dimensions into the DWSI, the framework provides a comprehensive tool for assessing and monitoring water security. This can support decision-making, policy formulation, and resource allocation to enhance water supply, sanitation, hygiene, and water governance practices in Debre Markos City. In conclusion based on the data, Debre Markos City's domestic water security level is classified as medium (2.43). Keyword: domestic water security index, variables, indicators, Analytical Hierarchy procedure, Debre Markos City, water security framework