Benmore Irrigation Scheme
Through strategic planning and the application of digital surveying models, Terra Vision successfully aided the irrigation of 4000 ha of land.
This landscape was originally deemed unfit for production so it was considered a huge breakthrough for the client. Plenty of challenges arose including extreme weather conditions and an earthquake faultline. The completion of this job opened up many new farming possibilities as well as hugely boosting the land value.
Our clients wanted to establish the viability of an irrigation scheme to provide water from the Twizel River at Lake Ohau to Omarama. A water right had been obtained but one question remained. For the scheme to be successful, water needed to get over the highest point between Twizel and Omarama, adjacent to Benmore Station.
We were approached to assist with this project and our role was to establish survey control benchmarks and create a digital terrain model of the entire scheme area up to the above-mentioned high point to ascertain the viability of the scheme.
We carried out the fieldwork in a very cold period during the winter and were able to determine that there was a difference in height between the river take point and the saddle mentioned of 9 metres. Given that this was over a distance of approximately seventeen kilometres, the resulting grade of 1:2000 was very flat. The contractors originally involved considered it too flat to be viable but our clients persevered and carried on with the scheme.
We set out the key points along the profile and construction commenced. This wasn’t without challenges as the course of the race was adjoining an old earthquake fault line, but was completed in very difficult conditions on time and on budget. The scheme has been hugely successful and resulted in the irrigation of over 4000 ha of land which was previously very low production.
After the water races had been constructed, we legalised the races across the various farms involved with a series of easements to protect the asset. For a privately funded scheme, the shareholders in the company are very pleased with the outcome and have given their farming operations huge versatility and options that were previously unattainable. From a typically barren moonscape vegetated sparsely with hieracium, the surety in water supply and application of modern agricultural methods and cultivation gave the area a massive boost and huge growth in capital value.
