| 補注區 | Recharge Area |
| 補注井 | Recharge Well |
| 循環蒸汽冷卻系統 | Recirculating Evaporative Cooling Water Systems |
| 再循環、回流 | Circulation |
| 再生 | Reclaim |
| 回收水 | Reclaimed Water |
| 回收水水質 | Reclaimed Water Quality |
| 回收水水質等級 | Reclaimed Water Quality Criteria |
| 回收水水質準則 | Reclaimed Water Quality Guidelines |
| 回收水水質標準 | Reclaimed Water Quality Standards |
| 可回收性 | Recyclability |
| 回收、回收再利用 (水再生利用-093) | Recycling |
| 再循環 (水再生利用-092) | Recycling |
| 再生原水 | Regenerated Water |
| 再生 | Regeneration |
| 可更新資源 | Renewable Resource |
| 貯水池、蓄水池 (海水淡化) | Reservoir |
| 剩餘水量 | Residual Amount of Water |
| 殘餘碳酸鈉 | Residual Sodium Carbonate (RSC) |
| 水再生 | Restoration of Water |