Aparanandā (Aparananda) was a river. Arjuna noticed this river during his 12 years of exile. While going towards Naimiṣāraṇya (Naimisharanya), he saw two rivers, with many lotus-flowers in full bloom — nadīñcotpalinīṃ ramyāṃ — one of them was called Nandā (Nanda), and the other, Aparanandā (Aparananda). King Yudhiṣṭhira (Yudhishthira) also visited this river. In Anuśāsanaparva (Anusasanaparva) of Mahābhārata (Mahabharata), these two rivers have been mentioned as sacred rivers , along with the description of Devavaṃśa and Ṛṣivaṃśa. So this river-site is known as a tīrtha (tirtha; site of pilgrimage), Scholars have identified this river as Alakānandā, especially in Brahmāṇḍapurāṇa (Brahmandapurana) —
tathā hyālakanandā ca nandā ca saritāṃ varā.
Since such a śloka (sloka; verse) exists, this notion (that Alakānandā and Aparanandā are identical) has been reinforced.
[See Nandā (Nanda)]