SB 9.15.12-13

sā cābhūt sumahat-puṇyā
 kauśikī loka-pāvanī
reṇoḥ sutāṁ reṇukāṁ vai
 jamadagnir uvāha yām
tasyāṁ vai bhārgava-ṛṣeḥ
 sutā vasumad-ādayaḥ
yavīyāñ jajña eteṣāṁ
 rāma ity abhiviśrutaḥ
Synonyms: 
— she (Satyavatī); ca — also; abhūt — became; sumahat-puṇyā — very great and sacred; kauśikī — the river by the name Kauśikī; loka-pāvanī — purifying the whole world; reṇoḥ — of Reṇu; sutām — the daughter; reṇukām — by the name Reṇukā; vai — indeed; jamadagniḥ — Satyavatī’s son, Jamadagni; uvāha — married; yām — whom; tasyām — in the womb of Reṇukā; vai — indeed; bhārgava-ṛṣeḥ — by the semen of Jamadagni; sutāḥ — sons; vasumat-ādayaḥ — many, headed by Vasumān; yavīyān — the youngest; jajñe — was born; eteṣām — among them; rāmaḥ — Paraśurāma; iti — thus; abhiviśrutaḥ — was known everywhere.
Translation: 
Satyavatī later became the sacred river Kauśikī to purify the entire world, and her son, Jamadagni, married Reṇukā, the daughter of Reṇu. By the semen of Jamadagni, many sons, headed by Vasumān, were born from the womb of Reṇukā. The youngest of them was named Rāma, or Paraśurāma.