The main purpose of the Lar river dam is to improve Tehran's water supply, providing irrigation water to the Vermain plain (southern watershed), and adjusting the Lar river's flow for irrigation of the Mazandaran plain (northern watershed).
The dam is located north-east of Tehran in the Alborz Mountains at about 2,500 m elevation.
Main characteristics of the projects:
- Eearth dam 105 m high and 1,170 m long.
- Main spillway on the right bank consisting of an overflow intake connected to a shaft at a 45° angle, 120 m long and 5 m in diameter. In the initial part of the work, this tunnel was used to divert the river.
- Irrigation system on the right bank consisting of a 1,100 m long tunnel, 5 m in diameter, a 57 m high damping well, 16 m in diameter, and a 78 m high well for operating the gates, with an excavation cross-section of 80 m2.
- 113 m long compensation tunnel, 3 m in diameter, which runs between the irrigation system and the main spillway.
- Works related to the diversion facility to supply water to Tehran, consisting of two tunnel intakes and a shaft for actuating the 67 m deep gates.
- Auxiliary spillway on the left bank consisting of a concrete overflow intake, an inclined junction 130 m long with a rectangular cross-section, 24 m wide, and a trapezoidal cross-section channel lined with gabions, about 700 m long.
|MAIN TECHNICAL DATA:|
|Required excavation with loose material: 13,500,000 m3|
|Required rock excavation: 835,000 m3|
Underground excavation: 120,000 m3
Excavation from borrow pits: 7,700,000 m3
|Dam embankment volume: 17,400,000 m3|
|Total volume of concrete: 95,000 m3|