Can an electric field align water molecules?

You get a rough estimate by comparing the energy lost by the dipole as it aligns with the field $sim d E$ with the thermal energy $sim k_B T$. Only when the former is much larger than the latter will the alignment be stable against thermal fluctuations. Taking this website's value for the dipole moment of water $$ d approx 1.85 D approx 1.85 times 3.34times 10^{-30} C m, $$ and $T = 300 K$, I get that $$E sim frac{k_B T}{d} = 6.7 times 10^{8} Vm^{-1}.$$ I would count that as a pretty strong field.