Because Kartaviryarjuna made the water flow in the opposite direction, the camp of Ravana, which was set up on the bank of the Narmada near the city of Mahismati, was inundated

Expressions researched:
"Because Kārtavīryārjuna made the water flow in the opposite direction, the camp of Rāvaṇa, which was set up on the bank of the Narmadā near the city of Māhiṣmatī, was inundated"

Srimad-Bhagavatam

SB Canto 9

Because Kārtavīryārjuna made the water flow in the opposite direction, the camp of Rāvaṇa, which was set up on the bank of the Narmadā near the city of Māhiṣmatī, was inundated. This was unbearable to the ten-headed Rāvaṇa, who considered himself a great hero and could not tolerate Kārtavīryārjuna's power.

SB 9.15.21, Translation and Purport

Because Kārtavīryārjuna made the water flow in the opposite direction, the camp of Rāvaṇa, which was set up on the bank of the Narmadā near the city of Māhiṣmatī, was inundated. This was unbearable to the ten-headed Rāvaṇa, who considered himself a great hero and could not tolerate Kārtavīryārjuna's power.

Rāvaṇa was out touring to gain victory over all other countries (dig-vijaya), and he had camped on the bank of the Narmadā River near the city of Māhiṣmatī.