Turbulence generated in bores is found to be sporadic and three dimensional when the Froude number is less than approximately 2.0. The turbulence characteristics behind the front are strongly affected by the behavior of the surface roller; the turbulence is created by intermittent advection of the recirculating flow of the surface roller. Although the one-dimensional approximation of a bore motion is identical to that of a hydraulic jump in an inviscid fluid, there are fundamental differences in a real fluid environment. When the Froude number is less than approximately 1.7, the difference in the shear-flow field between a bore and hydraulic jump affects their turbulence spreading rates.