Rock chutes are commonly used in waterways as a bed grade control structure to safely reduce channel slopes. They play an important role in stabilising waterways and protecting surrounding infrastructure. In practice, however, designing rock chutes is not always straightforward. While the e-Water Chute program is recommended in multiple guidelines, its results do not always align with outputs from other hydraulic models.
One of the key differences relates to the predicted location of the hydraulic jump along the chute. This is a critical design parameter, as it directly influences the minimum required chute geometry and overall stability. In addition, e-Water Chute has shown a high sensitivity to downstream boundary conditions. However, the assumptions utilised in the program are not always correct, which can lead to the overestimation or underestimation of the rock chute geometric elements.
To better understand these differences, this study compares simulations from e-Water Chute, HEC-RAS 1D, HEC-RAS 2D, and TUFLOW across a range of hydraulic scenarios. The confirmation of results across both TUFLOW and HEC-RAS 2D using the shallow Water equation was used as a reference benchmark to evaluate the accuracy and reliability of each approach. By systematically assessing model performance under varying conditions, the study aims to clarify where discrepancies arise and their significance.
The outcomes of this research will help practitioners better understand the strengths and limitations of e-Water CHUTE. Ultimately, the goal is to support more robust rock chute designs and enable more evidence-based decision-making in urban and rural waterways.