thumb|left|The Maggia delta with Ascona and Locarno (located on the northern part of the delta, above the river), seen from south
The Maggia is a river in the Swiss canton of Ticino, with a length of 56 kilometers. It derives its name from the village Maggia, situated on the river.
The springs are near the Cristallina mountain at 8136 ft (2480 m). The river runs through the Val Sambuco, the Val Lavizzara, and the Valle Maggia, and empties into Lago Maggiore between Ascona and Locarno.
The river is used for hydroelectric power production, e.g. with the dams of Lago del Narèt and Lago del Sambuco near the sources.
The Maggia river is a popular scuba diving spot due to its crystal clear waters.
In the 1990s the river had a European record: the river that grew fastest during rains. This characteristic led to many tragedies in the past. One involved the collapse of a bridge connecting the old Maggia to Aurigeno and Moghegno which killed many people in the 1970s.
Geography
The Maggia's main tributaries include the torrents Bavona and Rovana, as well as the Melezza river. The Maggia is one of the most torrential watercourses in Europe and experiences sudden and significant variations in water flow. While the river is not channelized, numerous sections have been developed through work carried out by a consortium from 1891 to 1930.
Flooding
The Maggia has experienced repeated flooding throughout its history, which was formerly exacerbated by the intensive practice of timber floating. The most catastrophic floods occurred in Cevio in 1648, killing 52 people, and in 1868, which resulted in 41 deaths.