The Ruamahanga River runs through the southeastern North Island of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. The river's headwaters are in the

Tararua Range The Tararua Range, often referred to as the Tararua Ranges or Tararua, is one of several mountain ranges in the North Island of New Zealand. The Tararua Range runs northeast–southwest for from near Palmerston North to the upper reaches of ...

northwest of Masterton. From there it runs firstly south and then southwest for before emptying into the

Cook Strait Cook Strait ( mi, Te Moana-o-Raukawa) separates the North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is wide at its narrowest point,McLintock, A ...

. The towns of Masterton and

Martinborough Martinborough ( mi, Wharekaka) is a town in the South Wairarapa District, in the Wellington region of New Zealand. It is 65 kilometres east of Wellington and 35 kilometres south-west of Masterton. The town has a resident population of The town ...

are close to the banks of the river. It is joined by many other rivers, including the

Tauweru River The Tauweru River, sometimes called the Taueru River, is a river in the Wairarapa region of New Zealand's North Island. It drains from the pastoral eastern highlands of the Wairarapa and joins the Ruamahanga River just north of the Gladstone Roa ...

near Gladstone. In its lower reaches, the river meanders across a large

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

, culminating in the

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

s around the edges of

Lake Wairarapa Lake Wairarapa is a lake at the southern end of the North Island of New Zealand, east of Wellington. The lake covers an area of , and at its deepest is . It is the third largest in the North Island, fractionally smaller than Lake Rotorua. The ...

. The river once flowed into the lake, but has now been diverted. The river drains at Palliser Bay further south. The river has now become generally polluted from sewage and farming that prevents people from swimming in the river or its tributaries.

References

Rivers of the Wellington Region Rivers of New Zealand {{Wellington-river-stub