| Subject | English | Estonian |
| energ.ind. | hydro-electric plant | hüdroelektrijaam |
| energ.ind. | hydro-electric power plant | hüdroelektrijaam |
| energ.ind. | hydro-electric power station | hüdroelektrijaam |
| min.prod., energ.ind., mining. | hydro-frac | hüdrofrakkimine |
| min.prod., energ.ind., mining. | hydro-frac | hüdrolõhkumine |
| min.prod., energ.ind., mining. | hydro-frac | hüdropurustamine |
| min.prod., energ.ind., mining. | hydro-fracturing | hüdrofrakkimine |
| min.prod., energ.ind., mining. | hydro-fracturing | hüdrolõhkumine |
| min.prod., energ.ind., mining. | hydro-fracturing | hüdropurustamine |