We assessed hydraulics habitat preferences for 12 non-salmonid fish species in 9 French regulated rivers. We used a data set of 80 000 fishes collected in 3100 electrofishing sample units. The hydraulic diversity of each sample unit was quantified by using the hydrosignature technique which provides the surface or volume percentages in a depth and current velocity cross classification. We analyzed the relationships between depth (HW), mean velocity (V) and fish total length (TL). Links between environmental and biological variables were different among rivers. Such differences could be due to different hydraulic conditions. A single robust system of linear equations (HW-V-TL) was also established for the whole 12 species and the 9 rivers. Using the 5M7 software and hydrosignatures of sample units, we calculated 4 suitable indexes for taxa per crossing clusters of depth and mean current velocity. Then, we evaluated the performance of these different indexes in predicting densities for each species. Calculations were not performed for fish with a total length upper than 200 mm, due to uncertainties in large fish habitat sampling and the small number of sample units available for this type of data. Using hydrosignatures within the hydraulic limits of the calibration data sets, fish occupation rate provided by the model can be used for spatial and temporal comparison of population densities.