  Computational models based on the depth-averaged shallow water equations
(SWE) offer an efficient choice to analyse velocity fields around hydraulic
structures. Second-order finite volume (FV2) solvers have often been used for
this purpose subject to adding an eddy viscosity term at sub-meter resolution,
but have been shown to fall short of capturing small-scale field transients
emerging from wave-structure interactions. The second-order discontinuous
Galerkin (DG2) alternative is significantly more resistant to the growth of
numerical diffusion and leads to faster convergence rates. These properties
make the DG2 solver a promising modelling tool for detailed velocity field
predictions. This paper focuses on exploring this DG2 capability with reference
to an FV2 counterpart for a selection of test cases that require well-resolved
velocity field predictions. The findings of this work lead to identifying a
particular setting for the DG2 solver that allows for obtaining more accurate
and efficient depth-averaged velocity fields incorporating small-scale
transients.
