Completed in October 2013 for TrustPower in the Hawkes Bay, the Esk Medium Hydro Civil Works Project comprised the construction of two Run of River Hydro Schemes with a combined generation capacity of 3.8MW. MAP Projects scope included all of the stream intakes, power stations and pipework’s. This work included:

• Construction of cut to fill earthworks on the Toronui storage Pond and powerhouses. Total volume of earthworks approximately 32,000m3 including 16,000m3 of cut to structural fill
• Construction of two major penstocks with a combined length of 3.2km and pipe diameter varying from 900mm down to 600mm. The penstocks were laid in GRP (2.1km) and steel (1.1km) and on grades varying up to 51% and invert depths of up to 10m
• Intake Structures were constructed in a live stream by diverting the water into bypass pipes. Heavy precast sections were fabricated for the inlet box and sluice ramp and the two main weirs were some 62m3 of reinforced concrete each with the top weir on the Rimu stream being 800m above sea level
• The two powerhouses were constructed with a reinforced concrete base some of which was precast at the main site and skidded down into place. The largest precast element to be lifted was 18t. Each powerhouse used some 80m3 of concrete. The building platforms are around 80m2 and the structural steel frame is 9m high and included a gantry crane at each powerhouse with a load of up to 22 tonnes for the generators.

From 2012

Bold hydroelectric scheme powers on

The wet Hawke’s Bay summer has put TrustPower’s 3.8 MW Esk Project hydroelectric scheme behind schedule but construction project manager Mark Prater says he is catching up fast.

“We have an end date of December 22 – we’ll be pretty close – but we’ll pick up time if we continue getting good weather like we are getting now,” he said. After the civil construction is complete the mechanical and electrical installation will get underway.

His experience on big projects in New Zealand and Australia has made him confident in MAP Project’s ability.

“If you can draw it we can build it – so long as you’ve got enough money.”

TrustPower Procceds With Esk Hydro

TrustPower Media Statement
7 February 2012

TrustPower Procceds With Esk Hydro

TrustPower has announced that it is about to begin construction of a new hydro electricity generation scheme in Hawkes Bay.

The scheme, to be known as Esk Hydro, will consist of two separate generating stations that draw on separate tributaries of the Esk River. Using special Pelton turbines designed specifically for use on high-head (pressure) the scheme will deliver 3.8 MW, and supply enough power for the equivalent of 1,800 average
New Zealand Homes

The Esk hydro scheme is TrustPower’s first generation project in the Hawkes Bay region and will directly support the company’s retail business including those customers in Wairoa and Poverty Bay and increasing numbers of clients in the wider Hawkes Bay region.

The project was initiated nearly 10 years ago by the owners of the land on which the scheme will be built. TrustPower acquired the rights to the project more than five years ago and since then worked with a very clever and practical New Zealand based team including electrical engineers, turbine designers, civil engineers, turbine fabricators and the civil construction team to produce an innovative kiwi designed and constructed solution that builds on TrustPower’s existing competence in owning and operating small hydro to medium schemes.

The scheme is fully resource consented, and follows the same environmentally sensitive design strategy as Trust{Power’s proposed schemes for the Arnold River on the South Island West Coast, and the Wairau River in Marlborough, in not requiring the damming of any waterways, and the use of relatively small and compact intakes and powerhouses.

The project will also be the first significant scale generation project in the region that does not rely on Transpower’s National Grid, and will therefore increase the efficiency of electricity supply to Hawke’s Bay.

The transmission solution was a key milestone for the project, requiring collaboration across many divisions of the Unison Group, both with TrustPower and with TrustPower’s consulting engineers.

TrustPower expects the $13 million scheme, which has an expected annual output of 15GWh, to be commissioned in June 2013.

Contractors engaged for the project are as follows:

Civil Construction – MAP Projects
Generators/turbine plant and equipment – AIE Hydroworks
Transmission – Unison Consulting
GRP penstocks – Maskell
Steel penstocks – Pipes NZ
Civil; Design – SKM