The floodwaters submerged the entire stretch of farmland.
Tips
usage
The verb 发大水 ('floods break out') is the idiomatic way to say 'it flooded'. Don't confuse 大水 (floodwaters) with 洪水 (hóngshuǐ, the more formal word for flood used in news and engineering contexts) — both are common, but 大水 is more colloquial.
