26 November 2014
What may be the longest-running collection of daily water clarity data in New Zealand has been boosted with the launch of a community-wide water-clarity monitoring programme.
The revitalised Cashmere Stream Care Group has been recruiting and training locals, schools and other groups such as local Girl Guides to take on a ‘citizen science’ role to help monitor water quality of Cashmere Stream in southeast Christchurch. Their inspiration is local resident Gordon Rudd, who has been taking daily water clarity measurements from the stream for the last four years.
Group member and EOS Ecology principal scientist Shelley McMurtrie recently led a training day for members of the public to follow Gordon’s lead.
“Gordon has taken daily measurements in the stream where it runs through his property since December 2010 with a dedication that can only be admired,” said Ms McMurtrie.
“He only stopped twice during that time—the day of 22 February earthquake and when he had to move out of his house for EQC repairs. Gordon’s data set is invaluable—and may well be the longest set of daily data in the country.”
The Cashmere Stream Care Group was initially set up in 2004 under Environment Canterbury’s Living Streams programme, but they went into recess following the September 2010 earthquakes —everyone except Gordon! In July 2013 some former group members and new residents got together to revive the group and to come back in a kaitiaki (stewardship) role for this river.
“The new programme will cover an additional 20 monitoring sites, each under the responsibility of individuals or groups to take weekly water clarity measurements,” said Ms McMurtrie.
“It’s a really great way for communities to contribute to quality science that underpins any actions to improve the stream.”
Ken Rouse, chair of the Cashmere Stream Care Group said the group had come up with a formal action plan, a living document to guide their ongoing work.
“Our mission is to protect and enhance the health of the Cashmere Stream and its catchment. We have met with landowners and councils to learn their plans for the future and what can be done to help the stream.
“We will also continue to reach out further into our local community for help in raising awareness of the issues,” said Mr Rouse.
Cashmere Stream is spring-fed, and collects water from ephemeral streams off the Port Hills and permanently flowing streams on the flats of Southwest Christchurch, flowing along the base of the hills before entering the Opawaho/Heathcote River. It has high ecological values, with freshwater crayfish/koura and blue-gilled bullies (both rare in Christchurch), upland bullies in its headwaters, and freshwater mussels/kakahi in its lower stretches.
Unfortunately it’s also at risk of ongoing sediment inputs, with past and present land use on the hilly catchments more of a challenge due to the fine leoss sediment particles that are proving difficult to remove with standard sediment erosion control practices. These fine sediment particles are also the main cause for the sediment issues in the Heathcote River, into which Cashmere Stream flows.
Shelley McMurtrie said; “sediment is one of the greatest threats to Cashmere Stream. It clogs up the gills of fish and invertebrates, similar to us trying to live in a smog-choked city. It settles and smothers animals and their spawning sites until they can no longer survive.”
Cashmere Stream Catchment is one of three priority catchments under the spotlight of the Christchurch-West Melton Zone Committee, who recognise that this community group is doing important works toward helping deliver the Canterbury Water Management Strategy. A recent report on the current ecological state of the stream, its current pressures and future options for reducing those pressures is available to download.
Cashmere Stream - Reducing the pressures to improve the state (PDF)