As discussed earlier, the Himalayan Rivers are perennial and their regimes are monsoonal as well as glacial. On the other hand the regimes of the Peninsular Rivers are only monsoonal, as they are controlled by rainfall alone.

The Ganga River has its minimum flow in the period from January to June. The maximum is at­tained in either August or September. The regime of the Ganga can be compared with that of the Jhelum which attains its maximum in June or even in may. The mean maximum discharge of the Ganga at Farakka is about 55,000 eusecs while the mean minimum is only 1300 cusecs. Amongst the Penin­sular Rivers the Narmada has very low volume of discharge from January to July which suddenly rises in August.

The Godavari flows at a low level until May. It has a double maxima-one in May-June and other in July-August. The mean maximum discharge of the Godavari at Valoparam is 3,200 cusecs, while the mean minimum flow is only 50 cusecs.