Possible Clues:

• Place for alligators
• Really wet spot
• Southwest current joins flood
• Washington, D.C., once
• Very wet area with many plants and animals
• American uncle quietly crossing wide marshy tract
• Overwhelm, or a relative of the first syllable of 20-, 36-, or 53-Across
• Low land that is seasonally flooded
• Mark has trade around Slough
• Muddy, murky place