Yauza Reservoir, reservoir in Smolensk Oblast, Russia

Yauza Reservoir is a river-type reservoir on the Yauza in Gagarinsky District, Smolensk Oblast, formed by a 910-metre concrete dam about 3 km north of Karmanovo. It has two branches: one runs some 15 km north along the Loknya valley, the other more than 20 km east along the Yauza, where the widest stretch reaches up to 5 km between shores.

The reservoir was created in the late 1970s after the construction of a dam that permanently changed the surrounding landscape. The project was part of a regional water management system designed for storage and local water supply.

The reservoir draws fishing enthusiasts from across the region, who gather especially in the shallow bays near small villages along the shore. On weekends, families come to the water's edge for swimming and walks, giving the place a steady rhythm tied to outdoor life.

The dam lies 3 km north of Karmanovo, is 910 m long and carries a road across it; water is released from a height of about 22 m. The reservoir is divided into three sections, with a ferry crossing at Yastreby and further landmarks at Kurdyuki and Vetrovo. The northern 4 km of the Loknya arm lies in Tver Oblast.

The reservoir is the most distant element of Moscow's water supply system, operated by Mosvodokanal; the Vazuza hydro system's management office sits in Karmanovo. Water is also pumped in from the Vazuza Reservoir through an 8 km canal, and the dam carries a road across its 910 m length.