The aspects of adaptating the moisture circulation system at the catchments of small watercourses to climate change based on the observational data from the Kamennaya Step' water balance station are considered. It is demonstrated that the transformation of the moisture circulation system results from the changes in the balance between the groundwater recharge and leakage with a decrease in the contribution of cryogenic factors to the river basin water regime formation. It is suggested that the transition period in the moisture circulation restructuring in river basins can be divided into two periods: with predomination of groundwater recharge and with predomination of its leakage. The length of the transformation phase in the steppe zone depending on the cryogenic factor is about 40 years. The final stabilization of the hydrological regime will depend on setting the groundwater balance under the specific hydrogeological conditions and anthropogenic load.