While the Greenough River is the largest (by catchment area) in the basin, there are several other notable systems in the Greenough River basin including the Hutt, Bowes, Chapman, Irwin and Arrowsmith Rivers. Bounded by the Murchison River to the North, and the Hill River to the South, the Greenough Basin lies in the Mid-West of the state, around the Geraldton area.
The climate is warmer and drier than Perth and the South-West. Geraldton on the coast receives an average annual rainfall of about 440 mm, and Mullewa, 85 km inland, receives an average of about 330 mm. Much of the basin has been cleared and the predominant land use is unirrigated cropping. Some areas of nature conservation are still present but mostly to the south, and on the coast south of Dongara.
There are no major dams but there is a reliance on groundwater which also is ecologically important due to its interaction with surface waters of many of the rivers in this basin.
Not all of the rivers in this basin flow to the Indian Ocean, the Arrowsmith River is an internally draining river, and terminates in a series of wetlands 3.5 km inland from the coast and has no river mouth or estuary. Similarly the Nambung river system drains internally into the underlying limestone geology east of the Nambung National Park with no opening to the Indian Ocean.