The Aviemore Dam is a dam on the

Waitaki River The Waitaki River is a large braided river that drains the Mackenzie Basin and runs some south-east to enter the Pacific Ocean between Timaru and Oamaru on the east coast of the South Island of New Zealand. It starts at the confluence of the � ...

in New Zealand. The dam is a composite dam, with an embankment section, and a concrete section. Built in the 1960s (and completed in 1968) it impounds

Lake Aviemore Lake Aviemore or Mahi Tikumu is a man-made lake in New Zealand's South Island, part of the Waitaki hydroelectric scheme. Immediately upstream is Lake Benmore and downstream Lake Waitaki. Aviemore lies on both sides of the border between the Wa ...

. Aviemore Dam is owned and operated by

Meridian Energy Meridian Energy Limited is a New Zealand electricity generator and retailer. The company generates the largest proportion of New Zealand's electricity, generating 35 percent of the country's electricity in the year ending December 2014, and is ...

, and its primary purpose is to power a

hydroelectric power plant Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

. It is a part of the Waitaki River Hydroelectric System, a scheme which supplies 30% of New Zealand's considerable amount of hydropower.

Characteristics

Composite Dam structure

The founding conditions of the dam differ on either side of the Waitangi Fault, hence different dam construction types are used. On the northern side of the valley (Canterbury side), the dam is founded on greywacke rock, and consists of a -long concrete structure. On the southern side of the valley (Otago side), the dam is founded on tertiary sedimentary rock, an consists of a long zoned embankment (earth) dam. During the construction of the concrete section, low-heat cement was first used in a large-scale application in New Zealand, to allow quick concrete pouring without the need for cooling elements. The dams spill outlets and penstocks are incorporated into the concrete dam section.

Hydroelectric facilities

The dam's hydroelectric generation facilities consist of 4

francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The proc ...

s each of , with a total capacity of total), with the generators being 4 x 11 kV. The facility produces approximately of electricity per year. The net

hydraulic head Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, ...

is , with the

penstock A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is inherited from the earlier technology of mill ponds and watermills. H ...

s (water pipes leading to the turbines) being the largest diameter in New Zealand at the time of construction, at diameter each.

Seismic enhancement

In the mid 2000's (decade), work was undertaken to enhance the dam and its appurtenant structures against the effects of earthquake loads, and to reduce the risk of overtopping resulting from earthquake-induced seiche waves in Lake Aviemore, in the event of rupture of the Waitangi Fault. At the time of construction the Waitangi fault had been considered inactive, but investigations in the early 2000's found the fault to be active (but with low probability of movement). The analysis and safety evaluation of the dam, and design of enhancements was led by URS Consultants, who received an ACENZ Innovate NZ Silver Award for their safety evaluation & upgrade.Aviemore Dam Seismic Safety Evaluation & Upgrade - ''Innovate NZ'', Brochure of the '2007 ACENZ Awards of Excellence', Page 13

References

External links

Meridian Energy power stations
(from