Previous research evaluating water scarcity in arid regions did not assess the geographical disparities in water security nor the impact of climate change impact on water security. Also, these studies predominantly overlook or downplay the significance of non-conventional water resources in ensuring water security. Current forecasts regarding the geographical disparities in the impact of climate change on water availability and net irrigation water requirements remain uncertain. Recognizing that water security evaluation encompasses more than traditional measures of availability and renewability, this study introduces a new framework in which water security is defined as a function of “availability,” “accessibility to services,” “safety and quality,” and “water management” at a very local scale. This framework introduces metric concepts to better manage water demand, accounting for conventional (renewable and nonrenewable fresh and brackish) and non-conventional water resources under climate change. Moreover, it considers the institutional adjustments necessary to address water scarcity, including factors of social resilience. The extent of water stress in the UAE was assessed by calculating the ratio of freshwater abstraction to renewability from conventional water sources. The calculated values were 16 (dry year), 9.2 (wet year), and 3 (wet year considering return flow as a recharge source). All measured values surpassed the optimal threshold level of 0.4, indicating a projected water scarcity in the UAE. Considering non-conventional water resources and the volumes of abstracted nonrenewable groundwater in the UAE’s total water demand, the measured water stress value amounted to 0.318 (optimal value: 0.4), suggesting a significant dependence on non-conventional water resources alongside low domestic food production (20%) to achieve water security. The groundwater contours and salinity maps for 2023 reveal a significant rise in the water table across the Quaternary aquifer in the UAE, marking the first occurrence in four decades. This rise is accompanied by a notable decrease in salinity levels, indicating substantial changes in fresh and brackish groundwater reserves. These shifts can be attributed to alterations in precipitation patterns and intensity, reflecting the impact of climate variability on the region’s hydrology. Such changes are critical for water resources management and may affect agricultural practices, ecosystem health, and overall water sustainability in the UAE.