Last updated October 2026
The Ruamāhanga River at The Cliffs is a river swimming spot near the small Wairarapa settlement of Gladstone, about 77 kilometres north-east of central Wellington, which makes it a day trip from the city over the Remutaka Hill. LAWA describes it as a popular spot for swimming, trout fishing and camping, reached from Dakins Road.
Greater Wellington Regional Council tests the water every week over summer, and the site holds a Fair long-term grade on LAWA: usually suitable, but best avoided after rain. The river here also gets toxic algae at times, and Greater Wellington has issued algae alerts covering this stretch, so check LAWA before every visit, especially if you have a dog.
Swimming Facts
Before you swim: Tested weekly Nov–Mar by Greater Wellington. Stay out for 48 hours after heavy rain. Latest result on LAWA
Today at Ruamāhanga River at The Cliffs
Monday 2 NovemberWater quality track record
What the grades mean
Excellent and Good: rarely unsafe for swimming. Fair: usually fine, but avoid swimming after rain. Poor: often unsuitable, especially after rain, so check the latest result first.
Grades use LAWA’s method: the 95th percentile of routine E. coli results over the five summers from 2020/21 to 2024/25, with at least 50 tests (465 per 100 mL from 61 tests).
Practical Information
- Location
- Ruamāhanga River near Gladstone, Wairarapa, accessed from Dakins Road
- Distance from Wellington
- About 77 km north-east of the city centre in a straight line; Gladstone is 15 km south-east of Carterton
- Water
- Freshwater river, no tides; flows change quickly after rain
- Water quality
- Fair (LAWA long-term grade, summers 2020/21 to 2024/25)
- Testing
- Weekly from November to March by Greater Wellington Regional Council; toxic algae is also monitored
- Toxic algae
- Recurring in summer: 13 of 88 checks between 2019/20 and 2024/25 reached alert or action level
- Facilities
- None listed at the river; bring everything you need
About the Ruamāhanga River at The Cliffs
Te Ara calls the Ruamāhanga the Wairarapa’s principal river. It rises in the central Tararua Range and flows south-east across the Masterton basin, then turns south-west down the eastern side of the Wairarapa basin before draining into Lake Ōnoke.
The Wairarapa Moana Wetlands Project, run by Greater Wellington, notes that the river passes all five Wairarapa towns and has a number of popular swimming spots along its length.
The river is very important to mana whenua. According to the Wairarapa Moana Wetlands Project, it was named by Haunui-a-Nanaia, the ancestor who also named the Wairarapa.
The name Ruamāhanga means “the two forks of the tree”: travelling down the river, Haunui-a-Nanaia came upon two birds caught in a bird snare in the fork of a tree and ate them, which gave him the strength to continue his journey.
The Cliffs is on the middle reaches of the river, near Gladstone, a farming district in Carterton District close to where the Tauweru River joins the Ruamāhanga. Gladstone is about 15 kilometres south-east of Carterton and is known for its country pub, the Gladstone Inn, and its school, which opened in 1876.
Te Ara notes that the river and its tributaries are known for trout fishing and swimming, and LAWA lists all three of swimming, trout fishing and camping at The Cliffs.
Fish and Game New Zealand describes the Ruamāhanga as mainly a brown trout fishery, with growing numbers of perch and rainbow trout, and notes that fishing access between Masterton and Martinborough is from road ends and bridge crossings. You need a current fishing licence to fish for trout.
Swimming and Water Quality at The Cliffs
Greater Wellington Regional Council samples the river at The Cliffs every week from November to March as part of its Recreational Water Quality Programme, and the results go to LAWA. The site has a Fair LAWA long-term grade, based on 61 routine tests over the summers of 2020/21 to 2024/25.
Across 73 tests between November 2019 and March 2025, 92% were suitable for swimming. A Fair grade means the water is usually fine for swimming, but it can become unsuitable after rain, when runoff washes into the river. LAWA also shows a day-to-day predicted status for the site, so look at it on the day you plan to swim.
Stay out of the water for at least 48 hours after heavy rain. Rain also raises the river level and speeds up the current, so a pool that is calm in a dry spell can be dangerous after a fresh. Check the depth before you jump or dive, and keep children within reach.
Toxic Algae
The Ruamāhanga gets toxic algae (cyanobacteria) in warm, settled weather. Greater Wellington describes it as leathery, dark green or black mats on the rocks in the riverbed, which can break off and collect at the river’s edge, where they dry to a light brown and have an earthy or musty smell.
Between 2019/20 and 2024/25, 88 algae checks at The Cliffs found 10 at alert level and 3 at action level, when people should stay out of the water.
In January 2025 Greater Wellington put a red alert on the river from Double Bridges to Kokotau, including The Cliffs, and advised people not to swim and to keep dogs out of the water.
Dogs are most at risk, as they can sniff out and scavenge algal mats at the river’s edge. Greater Wellington warns that a piece the size of a 50-cent coin can be enough to kill a dog.
Keep dogs away from the river’s edge whenever there is an alert, and take your dog to the nearest vet straight away if you think it has eaten algae. If you feel unwell after contact with algae, see a doctor or call Healthline on 0800 611 116. Check LAWA’s alerts before every visit.
Getting There from Wellington
From Wellington, take State Highway 2 over the Remutaka Hill into the Wairarapa and on to Carterton, then head south-east to Gladstone. LAWA notes that The Cliffs is accessed from Dakins Road near Gladstone. There are no facilities listed at the river, so bring water, food and sun protection, and take your rubbish home.
LAWA describes The Cliffs as popular for camping. Check the local council’s current freedom camping rules before you plan to stay overnight. A stop at The Cliffs fits easily into a day in the Wairarapa, with Carterton, Masterton and Martinborough all within a short drive.
Where to Learn More
LAWA and Greater Wellington Regional Council: the latest “Can I Swim Here?” result, toxic algae alerts and the long-term grade for the Ruamāhanga River at The Cliffs.
Greater Wellington Regional Council: how to recognise toxic algae in Wairarapa rivers, and what to do if a dog or person comes into contact with it.
Wairarapa Moana Wetlands Project: the Ruamāhanga River, its importance to mana whenua and the story behind its name.
Frequently Asked Questions
Can you swim at The Cliffs on the Ruamāhanga River?
Yes. LAWA describes The Cliffs as a popular spot for swimming, trout fishing and camping. Check LAWA for the latest water quality result and any toxic algae alerts before you swim, and stay out for at least 48 hours after heavy rain.
What is the water quality like at The Cliffs?
The site has a Fair LAWA long-term grade, based on 61 tests over summers 2020/21 to 2024/25. Of 73 tests between November 2019 and March 2025, 92% were suitable for swimming. Fair means it is usually fine but best avoided after rain.
Is there toxic algae at The Cliffs?
At times, yes. Between 2019/20 and 2024/25, 10 checks reached alert level and 3 reached action level. Greater Wellington put a red alert on the river from Double Bridges to Kokotau, including The Cliffs, in January 2025, so check LAWA before every visit.
What should dog owners know about The Cliffs?
Toxic algae is the main risk. Keep dogs out of the water whenever there is an alert, and watch them at the river’s edge even when there is not. A small amount of algae mat can kill a dog, so if you suspect your dog has eaten any, go to a vet straight away.
When is the water tested?
Greater Wellington Regional Council samples the river at The Cliffs every week from November to March and publishes the results on LAWA.
Where is The Cliffs and how do you get there?
The Cliffs is on the Ruamāhanga River near Gladstone in the Wairarapa, reached from Dakins Road. From Wellington, take State Highway 2 over the Remutaka Hill to Carterton, then head south-east to Gladstone.
Can you camp at The Cliffs?
LAWA describes The Cliffs as popular for camping. Check the local council’s freedom camping rules before staying overnight, and bring everything you need, as there are no facilities listed at the river.
Can you fish at The Cliffs?
Yes. LAWA lists trout fishing at The Cliffs, and Fish and Game describes the Ruamāhanga as mainly a brown trout fishery. You need a current fishing licence.
Spotted something incorrect on this page? Let us know.
Sources and data notes 1
- Water quality track record: Water quality: © LAWA and partner organisations (Greater Wellington), licensed under CC BY 4.0, results to April 2025.