In the final work, various methods of ensuring water supply on islands were analyzed, with a particular focus on the specific challenges posed by their isolation. Given that all islands face the same resource supply issue due to their distance from the mainland, ensuring a stable and reliable watter supply represents a significant challenge. The paper thoroughly examines the advantages and disadvantages of each available water supply solution, taking into account the needs of island communities. Using data from two islands in the Zadar archipelago as examples, a multi-criteria analysis was conducted to evaluate different water supply options and select the optimal solution for each island. The analysis included a comparison of various criteria such as costs, long-term profitability, environmental impact, and water supply quality. Additionally, it was explored how different prioritization of these criteria can influence the final results of the analysis and which options become more favorable when different criteria are set as a priority.