Amidst increasing water scarcity, the construction industry faces significant challenges due to its high water consumption. This study investigates the impact of using different water sources—tap water, river water, groundwater, and sewage water—on concrete strength. A total of 24 concrete cubes were prepared and tested for compressive strength after 7 and 28 days of curing. Results indicate that tap water and river water yielded satisfactory strengths, suitable for continuous use in concrete production. In contrast, groundwater and sewage water produced unsatisfactory strengths, with sewage water achieving only 77.6% of the required strength. However, saltwater cubes reached 90% of the expected strength, suggesting minor treatment could make groundwater viable. High levels of solids and salts in groundwater and sewage water hinder cement hydration. Establishing on-site treatment facilities could enable the use of saltwater and sewage water, promoting sustainable construction practices amidst growing water scarcity.