Meanderbelt Dynamics of the Sacramento River, California

2 Geomorphologist and Hydraulic Engineer, respectively, Water Engineering & Technology, Inc., Fort Collins, Colorado. Abstract: A 160km-long reach of Sacramento River was studied with the objective of predicting future changes in channel planform and their effects on water-surface elevations. Planform data were used to develop regression relationships between bend radius of curvature (Rc) and both short-term (5 years) and long term (90 years) lateral migration rates (MR) and migration distances (MD). A dimensionless cutoff index (Rc/MD) was developed to predict bend cutoff occurrence. Cutoffs occur when the cutoff index value is between 1.7 and 3.7. Channel planform controls water-surface elevations and bend cutoffs can reduce upstream water-surface elevations by up to 1 meter over a wide range of discharges.