an irrigation canal that conveys water from the Terek River to the plains of Severnaia Osetiia, the Chechen-Ingush ASSR, Stavropol’ Krai, and the Kalmyk ASSR. The Terek-Kuma Canal branches off from the left bank of the Terek River, at the stanitsa of Pavlodol’skaia, and extends to the Kuma River at the Levokumskaia Dam.
Built between 1952 and 1960, the canal measures 150.3 km in length. The headwork admits as much as 200 cu m of water per sec, and the mean annual flow rate is approximately 2.7 billion cu m, or more than one-third of the mean annual flow of the Terek. A total of 1.2 billion cu m of the canal’s water flows through the Kuma-Manych Canal, which branches from the Kuma River, and is conveyed to the Chograi Reservoir for the irrigation of the Kuma-Manych Depression by flooding and canal.
The canal, which conveys its water by natural water flow, has three knickpoints—Mozdok, Gor’kaia Balka, and Kuma. The Mozdok knickpoint is situated 21 km from the beginning of the canal and has a height of 7.9 m. The Gor’kaia Balka knickpoint, situated 113 km from the beginning, has a height of 7.9–31.6 m, and the Kuma knickpoint, 146 km from the beginning, has a height of 20.5 m. An emergency overfall with a flow rate of 50 cu m per sec has been built 82 km from the beginning of the canal.
Smaller flood-irrigation and canal-irrigation waterways, the Karanogaiskaia, Naurskaia-Shelkovskaia, and Kuma branches, originate at the Terek-Kuma Canal. In 1975 the canal provided water for the irrigation of 72,900 hectares (ha) of land by canal, and this figure was later increased to 146,000 ha. The area of land irrigated by flooding amounted to 2 million ha in 1975. A remote-control power system for hydraulic machinery is being installed.
REFERENCEOrositel’nye i obvodnitel’nye sistemy SSSR, fase. 1. Moscow, 1968.
I. A. DOLGUSHEV