The durability and compressive strength of concrete under various loads depend on the quantity and quality of the ingredients of the concrete mix. Water, cement, sand, and gravel are the most essential components of the mix. Selection of the right amount of cementitious material results in a correct and standard concrete mix. By controlling the quantity and quality of each component, we will not only achieve a standard mix, but also the desired compressive strength expected in the design stage of structures. So, this plays an important and significant role in realizing the required strength of a structural concrete element defined during the design process. In this study, the effect of altering water quality and type of gravel on the strength of concrete has been investigated. In the meantime, the effects of applying river and crushed gravel, along with river and well water on the strength of concrete have been investigated experimentally using 14 concrete specimens. Among these standard-sized concrete cylindrical specimens, 6 were made using crushed gravel while the remaining 8 specimens were made usinged river gravel. Half of either category of the specimens used ordinary well water while the rest used water from Helmand River, Afghanistan. All the specimens were cured under standard conditions in laboratory for 28 days. After completing the period, all the specimens were tested using a Schmidt Hammer as well as by the universal testing machine. The results indicate that the compressive strength of the concrete specimens made from crushed gravel is higher than those made from the river gravel. The results also show a slight increase in compressive strength of the specimens made with river water in comparison with well water.