Help at hand with new water restoration toolkit

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NIWA and partners have developed a 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.

Uretara Estuary Managers, a community group in Katikati, together with local Polytech students, are using the toolkit to assess and improve the quality of the Uretara stream and its surrounding environment.

The purpose of the toolkit is to recommend and describe a range of indicators for monitoring improvement in stream restoration projects. The toolkit document provides guidance in choosing indicators to match project goals, and using appropriate methods and timeframes for monitoring indicators.

“It’s about helping people getting going,” says NIWA freshwater scientist John Quinn. “And defining where they are going, then helping them get there… and about how to do things cost-effectively.”

The toolkit has been developed primarily for regional councils, but also provides options for community groups and resource users undertaking stream restoration, often without specialist equipment.

There are several indicators for each type of restoration goal. Most restoration projects aim to return streams towards more natural, pre-human conditions for biodiversity, physical habitat character, ecological processes, and water quality.

“In many places our stream looks pretty scungy and uninhabitable,” says Andrew Jenks, project manager of the Uretara Estuary Managers Group. “Lots of sediment enters the stream smothering habitat; high summer water temperatures add another layer of stress. Few aquatic species are capable of surviving these conditions.”

“Most of our objectives will be met by simply fencing and planting the riparian margin with well-selected plant species. Forty percent of the catchment is unfenced, and stock cause damage to already unstable banks as they enter the stream as they please,” says Jenks.

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. “We provide guidance on appropriate indicators depending on the goals of the restoration project and when to expect improvements,” says Quinn.

The end point, says Jenks, is to see the goals from the toolkit, which have been selected together with landowners, achieved. “We are lucky to have very supportive landowners and the ultimate aim of retiring riparian areas in the entire catchment, incorporating adjacent wetlands, looks quite feasible.”

Jenks will teach students from Tauranga AUT the techniques for the toolkit assessment. There are two groups of students doing the Marine Studies course and the Conservation course. They have 300 hours of available programme time to assist with the restoration work.

Uretara Estuary Managers Group is managing the project through funding from the Sustainable Management Fund, and the Western Bay of Plenty District Council, together with a 25% contribution from landowners.

The toolkit was funded by the Envirolink Tools programme through the Foundation for Research, Science and Technology.

 

Other information about this item:
Background
Five criteria have been developed for the Envirolink Toolkit:

a dynamic ecological endpoint is identified beforehand and used to guide the restoration
the ecological conditions of the river are measurably enhanced
the river ecosystem is more self sustaining than before restoration
no lasting harm is done
both pre-and post-project assessment is completed.

Success is measured in terms of how far a stream moves towards a natural regime. What that state would look like is typically defined by a comparable, but undisturbed, reference site, or by a guiding image of what the stream might have been like to prior to human disturbance.

To judge whether a stream has been measurably enhanced towards a predetermined dynamic endpoint depends upon measurements from the stream prior to impairment and some measure of reference condition are a comparable undisturbed minimally disturbed site.

The guidelines for restoration potential of a river are based on historical knowledge, undisturbed sites elsewhere, collective knowledge or models. And from this a ‘guiding image’ is developed.

Once the guiding image has been formulated, clear restoration goals can be defined and restoration success can be measured.

The key steps in designing your monitoring programme begin with identifying project goal and catchment constraints, understanding your restoration site, and having a clear image or reference site to aim for.