Source: The Great Interpretation of Dreams (Ibn Sirin)
A dry canal in a dream indicates the interruption of sustenance or the death of the one through whom sustenance flows.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A dry canal indicates unemployment and poverty.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A dry canal is interpreted as worry. Whoever sees one will be afflicted with worry.