How to determine the sediment carrying capacity of water flow significantly influences the calculations of sediment transport in rivers. Since the operation of the Xiaolangdi reservoir in 2000

low sediment concentration floods have occurred frequently in its lower reach

and changes in flow-sediment relationship have emerged

yet the existing methods for sediment carrying capacity calculation remain unimproved under these new conditions. Starting from the energy conservation theory

this study derives a formula for calculating sediment carrying capacity. By the criteria for channel erosion and deposition

we calibrate its parameters using 360 sets of relatively balanced flow-sediment data selected from the 2000-2010 records of the lower Yellow. And

additional 208 sets of balanced water-sediment data of 2011-2022 are used to validate its reliability and applicability. Results demonstrate the calculations align closely with measurements

confirming the formula’s accuracy in estimating this reach’s sediment transport capacity. A comparative analysis with classical sediment carrying capacity formulas

using 171 published water-sediment datasets

highlights the superiority of our new formula in application to low sediment concentration conditions. It is simple in structural form and enjoys a relatively high calculation accuracy; It is applicable to estimating the capacity of sediment transport in a low sediment river such as the lower Yellow

useful in practical river channel management and riverbed evolution analysis.