Blue Grey River
The Blue Grey River is a river of New Zealand.
It is an upper tributary of the Grey River, flowing from Lake Christabel, close to the township of Maruia Springs, and flowing west for before reaching the upper Grey River.
Little Grey River
The Little Grey River, also known as the Māwheraiti is a river of the West Coast Region of New Zealand.
It is a major tributary of the Grey River/ Māwheranui which it joins at Ikamatua.
The Little Grey rises in low hills above the Inangahua valley, its source being only from the Inangahua River.
It flows generally southwest, crossing the Maimai plain and the Ikamatua plain.
Both State Highway 7 and the Stillwater – Ngakuwau Line railway travel down the lower half of the river valley, crossing the river twice.
The river has two large tributaries, the Blackwater River and the Snowy River, both of which flow from the east.
On the left bank for the lower there are extensive tailings mounds resulting from gold dredging operations in the late 19th and early 20th centuries.
In 1946, both the highway and railway were temporarily closed while the dredge dug its way through to its new mining area in the Blackwater Valley.
This was the first and only time that such an event has occurred in New Zealand.
Upper Grey River
The Upper Grey River is a river of the West Coast Region of New Zealand's South Island.
As the name suggests, it is a stretch of the Grey River, and the name is used for the section between the confluence of the Blue Grey River, Brown Grey River, and Crooked Mary Creek in the Southern Alps and the Upper Grey's confluence with the Little Grey River 25 kilometres southwest of Reefton.
Grey River
The Grey River/ Māwheranui is located in the northwest of the South Island of New Zealand.
It rises in Lake Christabel, one of numerous small lakes on the western side of the Southern Alps, 12 kilometres southwest of the Lewis Pass, and runs westward for 120 kilometres before draining into the Tasman Sea at Greymouth.
The river was named by explorer Thomas Brunner in honour of New Zealand politician Sir George Grey.
The official name of the river was changed to Grey River/ Māwheranui in 1998 by way of the Ngai Tahu Claims Settlement Act 1998.
The Maori name for the river system and surrounding area is Māwhera, with Māwheranui being distinguished from the northern branch Little Grey River/ Māwheraiti.
The New Zealand Ministry for Culture and Heritage gives a translation of" broad and widespread( river mouth)" for" Māwheranui".
Numerous small rivers are tributaries of the Grey, and several of them also drain lakes.
Notable among these are the Ahaura River and the Arnold River, the latter of which is the outflow of Lake Brunner, the largest lake of the northwest South Island.
A small hydroelectric station is located on the river 25 kilometres upstream from the mouth of the river.
The Grey River's mouth is protected by a large sandbar, Greymouth bar, which is a notorious danger to shipping.
Raw sewage is discharged into the Grey River after heavy rainfall.
Historically, sewage and stormwater from Greymouth, Cobden and Blaketown were discharged without treatment directly into the Grey River.
Changes to the Grey District Council's wastewater schemes provide separation and treatment for sewage, except during periods of high rainfall, such as spring, when the capacity of the sewage treatment is exceeded.
Big River (West Coast, New Zealand)
The Big River, New Zealand is a river in the West Coast region of the South Island of New Zealand.
It is a tributary of the Grey River
Snowy River (New Zealand)
The Snowy River is a river of the West Coast Region of New Zealand's South Island.
It flows generally west from its sources within Victoria Forest Park, and is one of the rivers whose courses mark the edges of the Ikamatua Plain.
The Snowy River joins with the Blackwater River 100 metres prior to its junction with the Māwheraiti (Little Grey) River two kilometres north of the township of Ikamatua.
Brown Grey River
The Brown Grey River is a river of New Zealand.
It is an upper tributary of the Grey River, flowing from the slopes of Mount Kemp, close to the township of Springs Junction, and flowing southeast for before reaching the upper Grey River.
Alexander River (New Zealand)
The Alexander River is on the West Coast of the South Island of New Zealand.
It flows into the Upper Grey River.
Hongorai River
The Hongorai River is a river on the southern coast of Bougainville Island.
It is located within the Autonomous Region of Bougainville, in northeastern Papua New Guinea.
Grey River (Victoria)
The Grey River is a perennial river of the Corangamite catchment, located in The Otways region of the Australian state of Victoria.

Question: Are Little Grey River and Hongorai River both located in the same country?
Answer: no