Otinja (Macedonian: Отиња) is a river that bisects the city of Štip and is a tributary to the Bregalnica river. The river is of medium length, but the last part that flows through the city often dries up in the summer months as the water is blocked upstream for irrigation of the farms and vegetable gardens north of the city. The last 3 km of the river, that pass through the center of Štip are bounded by a quay, built of stone and mortar, which is criss-crossed by several bridges, including the medieval Stone Bridge of Štip (Macedonian: Камен Мост), and is integral part of the Štip downtown.
A hydroelectric plant has been started on the upper reaches of the river, north of the city, however the development has been stalled for a couple of decades now. The former mayor of Štip, Pande Sarev, has met in the past with the Dutch ambassador to Republic of Macedonia to discuss possible Dutch investments in the completion of the HEC "Otinja" as well as other projects in the city.
Coordinates: 41°44′N 22°11′E / 41.733°N 22.183°E