The completion of the Akarana Pond adds another string to BCI’s bow – our vision being to provide positive economic, environmental and social solutions in response to the challenge of sustainably managing our community’s water resource through employing innovative technology and outstanding people.
With a strong focus on investing in high quality intergenerational infrastructure, building the 1.5 million cubic meter Akarana Storage Pond has enhanced the scheme’s operational efficiency and reduced reliance on on-demand pumping.
As well as being a feat of engineering – its sheer size is impressive and state of the art construction utilises world class concept design, control systems and civil works methods – the successful commissioning of the Akarana Pond at the end of October also demonstrates successful collaboration between BCI and local landowners, regulators, and contractors who have all worked together to achieve this.
The Akarana storage pond will enable BCI to supply the peak seasonal demand for irrigation water without requiring additional pumping capacity at Trustpower’s Highbank Pumping Station. Whereas traditionally irrigation ponds are designed to improve reliability of supply, this dam will store water for the periods of peak demand from BCI’s shareholders, thereby enabling BCI to better control the long-term costs of delivery of water. This in turn provides economic benefits to the local community.
Irrigation and the Canterbury Water Management Strategy
The Canterbury Water Management Strategy identifies infrastructure as a means to contribute to all CWMS target areas, acknowledging that well designed and executed infrastructure can address future-proofing issues such as ecosystem support in a changing climate and water quality management through enhanced reliability and distribution efficiency.
The CWMS is a collaborative process involving all councils across Canterbury, and infrastructure development is based on cooperation and coordination, while recognising the commercial goals of the parties involved. Infrastructure options are considered and progressed by Environment Canterbury with a vision for an integrated water infrastructure across Canterbury. ECan facilitates the development of a regional infrastructure solution that aligns with all the targets of the CWMS and the recommendations in the zone and regional implementation programmes.
Resource consents to construct the Akarana pond were granted by Environment Canterbury and Ashburton District Council in line with the stringent guidelines set by the Resource Management Act.
Being classified as a large dam under the NZ Society of Large Dams guidelines, the construction received intensive engineering oversight during the construction period.
Situated adjacent to the RDR North East of Methven township, the pond is formed from gravel embankments with an internal HDPE geomembrane liner on the sides and a loess/silt liner on the base of the pond.
The pond is filled by diesel generator powered transfer pumps from the RDR and is connected to the existing BCI Methven pipeline to utilise the water by gravity.
The 40 hectare site has a maximum water depth of 5 metres. Construction started in February 2018 and the project was completed over an eight month period.
The $11 million project was fully funded by BCI and its bankers. BCI shareholders will service the ongoing cost of the infrastructure.
The Pond was designed by NZ owned and operated Damwatch Engineering, and built by Canterbury based contractors, Rooney Earthmoving Limited. Carrfields Irrigation installed the connection to the RDR, and Electraserve and Rubicon Water Management undertook the electrical and control works.