| Answer | Crossword Clue |
|---|---|
| EDDY | Sign of drainage |
| SCUPPERS | Drainage system of a ship. |
| AIRTRAP | Part of a drainage system. |
| WASTEPIPE | Part of a drainage system. |
| SUMPPUMP | Part of a mine drainage system. |
| GRANDTETON | Height of the Snake River drainage basin |
| NILEBASIN | Drainage area of the world's longest river |
