Vishvamitra had a large river, named Kaushiki, that was frequented by celestial Rishis. This sacred and suspicious river was frequented by the celestials and twiceborn Rishis.
विश्वामित्रस्य विपुला नदी देवर्षिसेविता। कौशिकी च शिवा पुण्या ब्रह्मर्षिसुरसेविता॥