| Benmore Dam | |
|---|---|
 | |
.png)  Location of Benmore Dam in New Zealand | |
| Location | Canterbury Region, New Zealand |
| Coordinates | 44°33′50.92″S 170°11′49.92″E / 44.5641444°S 170.1972000°E |
| Construction cost | $62 million |
| Dam and spillways | |
| Type of dam | Earth-filled dam |
| Impounds | Waitaki River |
| Height | 110 m (360 ft) |
| Length | 823 m (2,700 ft) |
| Width (crest) | 10.6 m (35 ft) |
| Width (base) | 490 m (1,610 ft) |
| Dam volume | 28 million tonnes |
| Spillway capacity | 3,400 km3 (820 cu mi) |
| Reservoir | |
| Creates | Lake Benmore |
| Total capacity | 1.25 km3 (1,010,000 acre⋅ft) |
| Surface area | 75 km2 (29 sq mi) |
| Maximum water depth | 102 m (335 ft) |
| Power Station | |
| Operator(s) | Meridian Energy |
| Commission date | 1965 |
| Hydraulic head | 92 m (302 ft) |
| Turbines | 6 x 90 MW (120,000 hp) |
| Installed capacity | 540 MW (720,000 hp) |
| Annual generation | 2,215 GWh (7,970 TJ) |
Benmore Dam is the largest dam within the Waitaki power scheme, located in the Canterbury Region of New Zealand's South Island. There are eight other power stations in the Waitaki Power Scheme.
The dam is the largest earth-fill (zoned embankment dam) water-retaining structure in New Zealand. Its core is low permeability clay material, supported by two massive shoulders of river gravel. Lake Benmore has a volume of 1.25 billion cubic metres, about 1.5 times as much water as Wellington Harbour. The dam's spillway can cope with over 6,000 cubic metres of water per second, about 20 times the mean river flow.
