Vision for Pūharakekenui/Styx River making progress The progress of a 40-year vision for the Pūharakekenui/Styx River catchment was front of mind for around 20 volunteers, community groups, boards and council staff who recently visited key sites along the river.

Environment Canterbury Councillor Phil Clearwater said he was really impressed to see how much The Styx Living Laboratory Trust (the Trust) had achieved using a collaborative approach.

“Learning how many different groups, organisations, schools, landowners and community boards the Trust has brought together is a real credit to their team.

“Their engagement with their community, whānau, landowners, governance, and wider takiwā/district is immense, and it was a real pleasure to listen and learn about their future goals for the catchment,” he said.

“Many thanks to the Trust for hosting the tour and sharing the challenges and opportunities facing the Styx River and its wider catchment area.”

Testing water clarity is a key method used to record the levels of sediment in the river - the less clarity means the more sediment is present

Trust’s vision for ki uta ki tai

The Trust was established in 2002 to work towards achieving Christchurch City Councils “Vision 2000-2040 The Styx”.

The 40-year plan was developed with the community and tangata whenua to understand both the challenges that the Styx catchment faces, and to seize the opportunity to protect and the river and its associated tributaries and wetlands.

Five key visions were developed to help guide the management of the catchment.

These focus on:

  • establishing a viable spring fed river ecosystem
  • creating a source to sea experience
  • developing a living laboratory for learning and research
  • enhancing the character and identity of the Styx
  • and fostering partnerships.

These visions continue to guide the Trust’s work within the catchment.

Funding for restoration boost for Trust

The Trust has received nearly $4.2m from the Ministry for the Environment’s Freshwater Improvement Fund to support restoration efforts through pest control, weed control, water quality monitoring and improvement, and engagement.

At the halfway point of the 40-year vision, Chair of the Board of Management for the Trust, Simon Rutherford is looking forward to seeing what the next ten years of whanaungatanga/collaboration can bring.

“As an urban waterway there are lots of challenges facing Pūharakekenui including sediment, erosion, land-use effects, decreasing water quality, pollution – but there are also many opportunities.

“Opportunity to build on what’s already been achieved and continue to fence, plant, monitor, record, share, grow, and learn alongside the community,” he said.

One area of focus for the funding is the Styx Mill Conservation Reserve, which the Trust considers ‘ground-zero’ for pest plant willow in the catchment. Eradication of willow in the conservation area is planned at a rate of 5ha per year for the next five years.

CCC's Biodiversity team leader Antony Shadbolt (left) explains how The Styx Mill Conservation Reserve will have targeted willow control over the next five years

“When we think about eradicating willow from 25ha of land it seems like a daunting challenge for a group of volunteers. By breaking it down into achievable year-on-year goals the task becomes more manageable and easier to measure and celebrate our successes.

“That’s really the approach we’ve taken for all our projects across the catchment,” Rutherford said.

Catchment water quality challenges

The catchment has more than 50ha of forested land. With flax, sedge, broadleaf and other native plant life like kahikatea, mataī and tōtara, the native birds, bees, and bugs are offered sanctuary in an increasingly urban environment.

The forested areas provide shade across the river, meaning a better environment for fish and invertebrates to thrive in. But the river still faces challenges like other urban waterways.

“Sediment is one of the biggest polluters of our urban waterways,” Environment Canterbury Pollution Prevention Officer Nick Moody said.

“Sediment smothers the stony riverbed, and fills in the gaps between the stones, where insects and fish usually live.

“Because Pūharakekenui isn’t like larger rivers, it doesn’t get flushed out in floods. So once sediment enters the stream, it’s almost impossible to get it back out. The key is to keep the soil on the land, through carefully managing subdivisions, and keeping cattle well back from the river’s edge.”

Pollution prevention officer Nick Moody explains how water clarity testing is carried out

Styx River water quality is currently rated ‘Fair’ which means it’s neither ideal, nor is it dire. The rating is something that needs to be held or if possible, improved.

“If we do what we’ve always done as a community, it will face the same issues as other urban streams and degrade over time. But if we take actions and support developers and groups like the Trust to protect it, then we can protect the Styx from being degraded as Christchurch expands to the North, and maintain the current water quality, Moody said.”

If you see sediment being discharged into stormwater drains or waterways please use the Snap Send Solve app or call the Environmental Incident Reporting line on 0800-765-588.

River home to rare native fish breeding site

Lamprey (piharau or kanakana)

In the Prestons area of the catchment, the Styx River is home to a rarely sighted species of native fish that is considered threatened.

Several years ago the CCC found a breeding site for the rare kanakana/lamprey while they were undertaking work in a boxed drain flowing into the Styx.

This species faces many of the same challenges as other native fish including sediment, habitat destruction, nutrients and erosion.

Preserving the area and continuing efforts to maintain and improve water quality provides increased protection for kanakana and other native species.

“It goes to show that even the most humble of waterways like boxed drains can be home to rare species, so we need to do all we can to protect waterways and the hidden gems living in them,” Moody said.

To find out more about the Trust and the work it does follow them on Facebook or visit their website.