We formulate an expression for the turbulent kinetic energy dissipation rate, $\epsilon$, associated with shear–generated turbulence in terms of readily measured properties of the flow or easily derived quantities in models. The expression depends on the turbulent vertical length scale, $\ell_v$, the inverse time scale $N$ and the Richardson number $Ri=N^2/S^2$, where $S$ is the vertical shear, with $\ell_v$ scaled in a way consistent with theories and observations of stratified turbulence. Unlike previous studies the focus is not so much on the functional form of $Ri$, but the vertical variation of the length scale $\ell_v$. Using data from two $\sim$7 day time series in the western equatorial Pacific the scaling is compared with the observed $\epsilon$. The scaling works well with the estimated $\epsilon$ capturing the differences in amplitude and vertical distribution of the observed $\epsilon$ between the two times series. Much of those differences are attributable to changes in the vertical distribution of the length scale $\ell_v$, and in particular the associated turbulent velocity scale, $u_t$. We relate $u_t$ to a measure of the fine-scale variations in velocity, $\tilde{u}$. Our study highlights the need to consider the length scale and its estimation in environmental flows. The implications for the vertical variation of the associated turbulent diffusivity are discussed.