. Brook lamprey habitat ‘preference’ for hydromorphological aspects of reference streams and assessment of potential streams. Preference is based on habitat assessments (field estimates) in current brook lamprey habitats of ten streams (Keersop, Beekloop, Osinkbemerbeek, Willinkbeek, Egelsbeek, Geelmolensche beek, Springendalse beek, Rode beek, Zieversbeek and Kendel) explored by Spikmans et al. (2013). Boxplots show the median, 25% lower and 75% upper quartile (gray bars) and the minimum and maximum values (whiskers) observed. Values of the habitat ‘assessment’ (field estimates) by Spikmans et al. (2013) are given for the Reusel stretches Utrecht, Wellenseind and the Spruitenstroompje tributary stream. Reusel ‘downstream’ gives an average value which includes three areas; Moleneind, Turkaa and Hilver.