bottomland

Flat land along a river, lying a few feet above normal high water, naturally fertile, and often consisting of alluvial deposits.UScountableuncountable

• Near-synonyms: lowland, lowlands, alluvial plain, floodplain, mudflat, mudflats
• It was a fantastic farm because it had it all: high meadows, woodlots, orchards, springs, rich bottomlands, and river access.