River of the Month - Maitai

This month’s featured river is one of Nelson’s treasures, the Mahitahi or Maitai river. Flowing through the city this beautiful river is widely used by the people of Nelson and a taonga that they are determined to protect.

 The Maitai/Mahitahi is a beautiful river running right through the middle of Nelson City. It originates in the hills surrounding the city and flows through rural, recreational and residential areas, then past the city centre to where it meets the sea at the Nelson Haven. On sunny days the banks are lined with people having lunch and walking, running or biking along the riverside path.

The river is the tupuna awa (ancestral river) for the iwi of Whakatu and is very important to all the iwi of Te Tau Ihu. It is an historical Mahinga kai, a source of pakohe (argillite) for tool making, and was the main route from Nelson to Pelorus and Marlborough. Although the current name of the river is Maitai, one of the original names for the river was the Mahitahi. Mahitahi can mean working as one, or working together. For some iwi it referred to the inanga that were plentiful in the river and who appeared to swim as one. For other iwi it related to working as one with the precious argillite or pakohe that is found in the headwaters.

Anne Devlin WINNING Photo

Photo: Children play in the Maitai. Anne Devlin

There are several very accessible and much loved swimming holes within walking distance of the CBD, people picnic and walk their dogs along the river, it’s popular for white baiting and has been a good trout fishery in the past. At high tide kayakers and Waka Ama crews paddle up from the Haven. It’s possible to walk, run or bike from the sea 8 kilometers up the Maitai Valley on the riverside path, which incorporates art works and interpretation panels along the way. Further up the river in the mid-catchment are a series of mountain biking tracks, a golf course, and a campground, and this area is also popular for picnicking, swimming and adventure racing.

The river is connected to the estuary and coast at one end and a pristine native bush area is intact above the reservoir in the upper catchment of the Maitai/Mahitahi and the Brook. Inanga spawn along the grass verges just above Collingwood Street Bridge in the city centre and a recent fish survey found longfin and shortfin eels, common, redfin, giant and bluegill bullies, torrentfish, inanga, koaro, smelt, brown trout, koura.  The Maitai/Mahitahi was one of first rivers to be populated with trout (in 1869) and the original hatchery building constructed in 1867 is still present in Albion Square.

The river is the main source of drinking water for Nelson and the North branch in the upper catchment has been dammed to create a reservoir. Drinking water is mostly taken from the South Branch, and water from the reservoir is then fed back into the river to offset what is removed.


Nelson’s treasure threatened

There has been increasing community concern recently about the health of the river with the community noticing changes in the river.  

Many of the issues affecting the river are the result of increasing levels of fine sediment, bacteria and nutrients in the river, which are not only affecting the river’s ecosystem but are also impacting on how people can use the river. E. coli levels are often exceeding the recreational bathing limits in the lower catchment, meaning it isn’t always safe for swimming. There are increasing episodes of algal blooms, including the sometimes toxic cyanobacteria

Susie Wood Dr David Kelly Ebon Arist Holly Mills Emily Blaney Oct 14

Photo: Scientists study cyanobacteria in the Maitai

In a survey earlier this year, Nelson residents told the council they believed it was important for Council to focus on water quality in local streams and rivers. Many of those who had concerns about water quality in local streams and rivers identified Maitai River as the greatest concern.

In response, Nelson City Council established a programme to address the issues affecting the health of the river. At the same time and independent of the Council, community group Friends of the Maitai was regrouping.

The original Friends of the Maitai was formed in 1977 and the group has existed several times over the past 60 years, when there have been issues surrounding the river. The group promotes collaborative responsibility for the health of waterways and gives community members a gathering place to learn about the issues that face our river and work together to take positive action.

 Viewing collaboration as the best chance of success, Nelson City Council and Friends of the Maitai formed a partnership to deliver the programme of work known as Project Maitai/Mahitahi.  The goal of Project Maitai/Mahitahi is to work together with Iwi and the community to improve the health of the Maitai/Mahitahi River so that people can swim safely, collect kai and value this taonga as an integral part of Nelson’s physical and cultural landscape.

 This year Nelson City Council has put $400,000 towards 12 projects to begin to address the issues. The projects include:

  • Community Projects: funding for community projects that will help meet the goal of Project Maitai/Mahitahi
  • Riverside Planting: planting native trees, shrubs and grasses on the river banks to cool the water and provide habitat for native species
  • Maitai Dam: improving the water quality in the Maitai Dam so that it doesn’t affect the river
  • River Flows: changing flow rates from the Maitai Dam so they are more like natural river flows.
  • Stream Biodiversity: helping native fish and healthy stream bugs make the Maitai/Mahitahi their home, and improving fish passage
  • River Gravel: understanding how gravel could move down the river in a natural way, without causing a flood risk or a barrier to fish migration
  • E. coli Chasing : finding out where the bacteria in the swimming holes downstream of Riverside Pool are coming from, and fixing any sewerage leaks found
  • Forestry Review: working with forestry companies to reduce the impact of logging on the river
  • Stock Fencing: making sure cattle can’t get into the river
  • Brook Culvert: making the Brook Stream as fish friendly as possible, while still reducing flood risk

The value of community

Project Maitai/Mahitahi doesn’t represent all the work that is being done to understand or address water quality issues in the Maitai/Mahitahi river.

Maitai Planting Day 10 Aug 2014

Photo: Maitai River tree planting day

There are several other related projects in place at Nelson City Council, and the Friends of the Maitai run their own programme including river monitoring, planting days, community education and water quality advocacy. There is also a group based at Victory School who are advocating for improvements to the York Stream, a tributary of the Maitai.

The Cawthron Institute has a long history of studies in the catchment, and is currently hosting five students who are doing studies on the Maitai/Mahitahi River.

Cawthron Freshwater Ecologist Roger Young says that “after working on rivers all over the country it’s great to be looking at solutions to water quality issues in our own local river.”

Nelson City Councillor Brian McGurk says that Nelson’s success in reviving the Maitai relies on everyone working together to drive changes over time.

“The key to the Project Maitai/Mahitahi is a strong sense of guardianship by people who live, work and play alongside the Maitai River. That community involvement must be reinforced by robust science and ongoing research that supports an understanding of the issues impacting upon the river and its health.

“There is no single solution for achieving better water quality. Working closely with Iwi and the community, we must introduce a whole raft of measures to make a difference. The value of community involvement and support of the science community cannot be overstated.”

He believes Nelson City Council has a key part to play in restoring the Maitai River. 

 “The entire river catchment lies within our boundaries, flows through our city centre and is at our front door.

“The Nelson City Council is one of the largest landowners in the river catchment and the Council’s own activities have a significant impact on the river; as a dam operator providing water storage, forestry activities, flood protection, storm water, accidental discharges and overflow of sewerage into the water way. The council also administers the reserves along side the river and has a regulatory function. We are getting our own house in order so that we can be a role model for other key players.”


Looking for more information?

 You can read more about the Maitai River and the community restoration efforts at the following links:

 The Friends of the Maitai



Nelson City Council




The Cawthron Institute:






Victory School and the York Stream group




The Brook Waimara sanctuary


The Prow - a website featuring historical and cultural stories from Nelson, Tasman and Marlborough (search on Maitai or Mahitahi)