Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 4

Sanskrit:

श्रीशुक उवाचकालिन्द्यां कालियस्यासीद् ह्रद: कश्चिद् विषाग्निना ।श्रप्यमाणपया यस्मिन् पतन्त्युपरिगा: खगा: ॥ ४ ॥

ITRANS:

śrī-śuka uvācakālindyāṁ kāliyasyāsīdhradaḥ kaścid viṣāgnināśrapyamāṇa-payā yasminpatanty upari-gāḥ khagāḥ

Translation:

Śrī Śukadeva Gosvāmī said: Within the river Kālindī [Yamunā] was a lake inhabited by the serpent Kāliya, whose fiery poison constantly heated and boiled its waters. Indeed, the vapors thus created were so poisonous that birds flying over the contaminated lake would fall down into it.

Purport:

In this regard the ācāryas explain that the Kāliya lake was situated apart from the main current of the river; otherwise the Yamunā’s waters would have been poisonous even in cities like Mathurā and in other places farther away.