Omahau, along with Bendrose, and Ruataniwha Stations once formed part of a larger run, Ben Ohau, acquired from the MA?A?ori owners under the Kemp Deed of Purchase 1848. Then in 1857, H and S Fraser applied for Ben Ohau.
After Ben Ohau's subdivision into the three Stations in 1918, Omahau Station subsequently become Crown Land subject to the Land Act 1948.
An 188-Hectare (470 acre) farm, Omahau grazes merino sheep and a few cattle. Its proximity to Twizel and Mt Cook allows easy access to both town facilities and the outdoor activities associated with the rivers, lakes, and mountains.
Omahau Downs in the Mackenzie/Waitaki Basins, forms part of a nationally recognised and regionally outstanding landscape. A visually dramatic backdrop to Twizel and the lower Mackenzie Basin are the very steep slopes rising from the outwash plains of the Ben Ohau Range and catchments.
The vegetation varying from short tussock grasslands and matagouri, to shrub-lands and tall tussock grasslands. It's also a habitat for a number of endangered animals.
The braided waterways, swamps, gravel beds, and tributary streams of Omahau are important habitats for many birds. These vertebrates include the black stilt, banded dotterels, pied stilt, South Island pied oystercatcher, brown bittern, marsh crake, grey duck, New Zealand shoveler, New Zealand scaup and the occasional white heron. The flats are important for black stilt management.
The lower Twizel River is an important nesting area for riverbed birds, such as black stilts, wrybills, and banded dotterels.
While beneath the tussock cover lies a flourishing population of insects, lizards, beetles, mountain grasshoppers and alpine weta - a unique species that literally freezes during the winter.
As well as being a highly valued natural setting, the Basins are also the location for a range of tourism attractions and recreational pursuits. To the North of the Station are the Twizel and Tekapo Rivers; while to the South is the Ohau River.
The Tekapo River, supports a high number of takeable fish and, while not as fruitful as the Tekapo, the Twizel River is still an important fishery in its own right.
The fringes of the flats receive a variety of use from fishing and horse riding to limited four-wheel drive. From trail bike use, to passive recreation and natural history activities. The hill block gets some use for paragliding, mountain biking, running, and tramping.