backed-up water level

例句：

1. 1.The reservoir is at a backed-up water level, ready to release water when needed.
   水库处于备用水位，随时准备释放水。
2. 2.The flood warning indicated that the water level was backed up.
   洪水警告表明水位已经上涨。
3. 3.The engineers were monitoring the water level closely to ensure it didn't get backed up again.
   工程师们密切监控水位，确保它不会再次上升。