Abstarct: In recent years, various studies have been conducted on managing water resources and maintaining the quantity of water all over the world, including Iran, which has a hot and dry climate and has faced water shortages and drought. The present study sought to evaluate the effect of compacted foam surface covers with cement slurry and plastic balls with 50 and 80% coverage levels, as well as the combined method (compressed foam and plastic balls) with 80% coverage in a standard Colorado pan on evaporation reduction. In this way, the ease of access, reasonable price, and the lack of a negative impact on water quality are among the advantages of the materials used to cover the surface. By monitoring the effect of the mentioned methods on reducing the evaporation rate, it was found that using the two mentioned materials, which included compressed foam and plastic balls in equal proportions, with 80% coverage of the reservoirs’ surface could reduce the evaporation rate by 68%. Moreover, the use of the ball and compressed foam alone with the same 80% coverage level decreased the evaporation rate by 58 and 53%, respectively. By reducing the reservoir coverage level to 50%, the use of the foam and ball alone could reduce the evaporation rate by 28 and 34%, respectively. Monitoring the evaporation in January showed that the coverage 80% of the water reservoir surface with a combination of foam and plastic balls with the same surface ratio allowed reducing the evaporation rate by about 77% while the use of balls and foam alone led to a 65 and 53% reduction in evaporation rate, respectively. Ultimately, the 50% coverage of the reservoir surface in January with ball and foam materials decreased the evaporation rate to 41 and 27%, respectively. From the viewpoint of statistical analysis and the data received from Semnan synoptic station in December, there was a significant positive correlation between the average temperature and the evaporation rate of control pan and pans containing the ball, foam, and their composition. In January, however, a significant negative correlation was observed between the relative humidity and the pan containing the ball 80%. In this research, foam 50%, composite 80%, foam 80%, ball 80%, and ball 50% had better performance in terms of the best water quality baxsed on the water electrical conductivity (EC), respectively. Finally, the coverage level of 80% (combined) was selected as the best coverage, by using hierarchical analysis (AHP) and considering different criteria.