Up the creek - with a plan

Just metres from the view of thousands of motorists every day on the Southern Motorway is the embattled Otara Creek.
Once a thriving eco-system of native fish and plants, the creek banks have been cleared of vegetation for decades of farming and more recently for industrial developments.
But the tide is turning on the harsh fate handed to this body of water and surrounding land.
The latest assistance is in the shape of a new water restoration toolkit, an online how-to guide for community volunteers, school groups and environmental scientists trying breathe life back into Otara Creek. .
NIWA and partners have developed the new Envirolink toolkit for monitoring the ecological success of stream restoration.
The Envirolink toolkit is now being used in projects to restore streams around New Zealand.
In Auckland, the toolkit is being used for a large restoration project located at Otara Creek, in Manukau. This work aims to offset impacts of building a second runway at Auckland Airport.
Project Manager at the Otara Creek restoration project is Andrew Jenks. He says: "We have a wide range of school and community groups involved in the project, so the toolkit will get a great work-out here over the next year. It is a most useful and adaptable resource for our purposes, and we will be intertwining educational observations within selected assessments for students."
The toolkit has been developed primarily for regional councils, but also provides options for community groups and resource users undertaking stream restoration without specialist equipment.
NIWA freshwater scientist Dr Richard Storey is assisting with the Otara Creek restoration.
Dr Storey's assessment shows that much work needs to be done. "It's a barren site - not attractive - the creek is surrounded by large buildings. Foam has been detected coming from a storm water pipe, into the creek. The stream is silty. Cattle have been grazing near the area, and around the stream."
In spite of this, the stream has reasonable potential to provide for good ecological habitat. Branches have been piled up beside the creek to form habitats for lizards, and to improve biodiversity. "We found a giant kokopu in the creek. There are large water pools, which could be good for fish, but there is also a weir in the stream, which isn't good for fish migration," says Dr Storey.
How does the toolkit help?
The Envirolink toolkit recommends and describes indicators for monitoring improvement in stream restoration projects. The comprehensive toolkit handbook provides guidance for choosing indicators to match project goals, and using appropriate methods and timeframes for monitoring those indicators.
There are several indicators for each goal. Most restoration projects aim to return streams towards more natural, pre-human conditions for biodiversity, physical habitat character, ecological processes, and water quality. A key component of being able to judge the ecological success of restoration is having a defined "endpoint" that the restoration is trying to reach.
"It's a structured way of setting appropriate goals," says Dr Storey. "It gets you to think about the context you're working in, and what you can achieve in a restoration project: what is possible and what is not."
This Otara Creek restoration involves establishing more than 100,000 native plants around the creek. Contractors will do most of the planting, and 44,000 plants have been established so far. Local businesses and schools from the area will do 15 per cent of the planting.
Andrew Jenks and the local community restoration group have clear objectives for the restoration. These objectives centre on natural habitat, aquatic biodiversity, ecosystem functioning, water quality, terrestrial biodiversity and recognition of the cultural value of the stream.
"Our key objectives are to improve habitat for native fish and greatly reduce the quantity of aquatic weed. Fortunately we have discovered a relatively undisturbed site just upstream (now incredibly rare in our area), and this displays many of the features we hope to replicate including stable banks with undercuts, good pool riffle and run sequences plus tiered canopy providing lots of shade. It will take many years to reach this endpoint but we are setting things in place now to get these key features re-established as soon as possible," says Mr Jenks.
The toolkit was funded by the Envirolink Tools programme through the Foundation for Research, Science and Technology.
More info:
www.niwa.co.nz/our-science/freshwater/restoration-toolkit