Dipped in flour

• Hauled up (from depths)
• Scraped the bottom of
• Changed channels, in a way
• Saved from obscurity, with "up"
• Unearthed, with "up"
• Made deeper, as a shipping lane
• Unearthed (with "up")
• Sprinkled with flour

Wiktionary Word definitions in Wiktionary
vb. (en-past of: dredge )