The length of time it takes to study hydrology can vary depending on the level of education you are pursuing. A bachelor’s degree in hydrology or a related field typically takes four years to complete. A master’s degree in hydrology or a related field usually takes two years to complete, while a Ph.D. in hydrology or a related field typically takes three to five years to complete. It’s important to note that these are general estimates, and the actual length of time it takes to complete a degree in hydrology can vary depending on the institution and program.