Water tour resounding success

Christchurch water. It's on everyone's mind as chlorination and water restrictions have been put in, climate change is a concern, and there's a perception that our once pristine water is no longer pristine.

So what is actually happening under our feet here in Christchurch?

That's the question the Christchurch West Melton Water Zone Committee sought to publicly address through its free field trips which followed Christchurch's water from the source at the Waimakariri River, through the city and out the end to the Heathcote River.

Around 70 people gave up a Saturday to attend the trip following Christchurch's water from the Wamakariri River through to Bell's Creek in Linwood- a stream which receives all of Christchurch CBD's stormwater.

Supported by Environment Canterbury, Christchurch City Council and the Waterways Centre for Freshwater Management, members of the public had the opportunity to see first-hand how Christchurch's groundwater system works and ask the experts questions directly.

Along the way, they learnt about how Christchurch city was vulnerable to flooding from the Waimakariri River due to its positioning along an alluvial fan and what flood protection measures are in place to prevent it flooding.

They were also able to see what unconfined and confined aquifers looked like and how the water moving through the groundwater system remained clear and of a high quality between the Waimakariri River and Redwood Springs.

Stormwater polluting waterways

However, the visit to Bells Creek in the afternoon told a different water story.

Stormwater from the buildings and roads in the CBD flows directly into Bell's Creek. Consequently, the creek has become polluted with heavy metals such as copper, zinc and fine sediment and can’t support much aquatic life.

The tour concluded with a visit to a former football field turned retention basin and urban forest in Linwood which helps filter contaminants from the water from Bell's Creek and acts as a flood protection zone, and a look at Christchurch City Council's new stormwater treatment plant which removes the heavy metals from the water before pumping it out to the Heathcote River.

Find out more about what you can do to help keep our waterways clean.

Chlorination of the city's water

Those on the tour also got to see some of the new wellheads Christchurch City Council is installing so they can remove chlorination. People got to ask questions directly to council staff regarding the chlorination of the city's water.

Participant John van Garderen said he learnt more than he expected to on the field trip.

"To be placed at the riverbank of the Waimakariri and then follow a drop of water through the processes to my city home tap, with all the considerations needed to supply that valuable resource, became to be seen by me as a privilege we have this water, rather than a right.

"That it can arrive clean and drinkable, by means of careful control and considerations of protecting the water environment by the combined Christchurch City Council, Environment Canterbury and engineering interests is remarkable," John said.

Julia from the Styx Living Laboratory said the water zone committee’s idea of taking people out and showing them first hand where Christchurch's drinking water came from was "brilliant".

"The fact that there was plenty of time for questions was great, especially with sensitive issues like the chlorination of the water," she said.

Dirk van Garderen said he enjoyed seeing and experiencing some of the challenges as well as triumphs involved in supplying Christchurch's water.