تحديداً شمال بينريث، عند تقاطع نهرغروس Grose وبالقرب من Yarramundi، ساعتها نيبيان يصبح نهر Hawkesbury.
Near Wallacia it is joined by the dammed Warragamba River; and north of Penrith, near Yarramundi, at its confluence with the Grose River, the Nepean becomes the Hawkesbury River.