Owing to the marginal success in abating pollution sources in water systems, integrated catchment management plans are being increasingly implemented in hopes of improving water quality. Transferring data and concepts between subbasins in the catchment is often used to fill knowledge and data gaps. Conducted here is a comparative study of three catchment areas of similar size, two neighboring stream basins in Uganda and one in central Russia, to investigate important prerequisites for transferability of data between basins. Compared were ions (Ca, Cl, Fe, K, Mg, Mn, Na), nutrients (NH4-N, NO3-N, dissolved and particulate P, SO4), discharge, suspended sediment, pH, and alkalinity with attention given also to the climatic, soil, and land-use characteristics of each catchment. Significant statistical differences were found in the parameters, even of the adjacent lying catchment areas in Uganda. The substance regime in the Russian stream is dominated by the snowmelt events whereas that in Uganda by the rainy season pattern. The phosphorus dynamics were markedly different between the two adjacent catchments in Uganda. Although the climates and the chemical composition of the soils of the two basins are quite similar, slight shifts in land-use distribution can alter the processes dominating in the transport of phosphorus. This is indicative of the sensitivity that parameters of individual basin characteristics (even small neighboring basins) can have on the outcome of the substance regimes and fluxes. These sensitivities highlight the precision required in defining the processes to make transferability of data and models across subbasins in a catchment management system as successful as possible. Keeping such systems flexible and modular (object-oriented approach) can alleviate these difficulties.