This book presents physical and hydraulic characteristics for 78 New Zealand river and canal reaches which may be used as reference reaches for estimating roughtness coefficients in similar channels. These reaches cover a wide range of mean flow (ranging from 0.1 to 353 m3/s), slope (ranging from 0.00001 to 0.042), and bed material (ranging from silt, through sand, gravel, and boulders to bedrock). The information given for each reach includes colour photographs, cross-section and planform plots, bed and bank descriptions, bed surface material size gradings, plus tables and plots showing how the Manning and Chezy roughness coefficients vary with flow magnitude.