An entry from Ruth Gardner's blog for 24 April 2012 entitled, "Autumn on Avon".
The 2011 Christchurch earthquakes and the sewage outfall diversion have had profound impacts on the Heathcote-Avon Estuary
When Christchurch was Young Written for Ellesmere Guardian by Mr W. A. Taylor, 1944 The Avon river (Otakaro) predates its sister stream the Heathcote (Opawaho) as a navigable course to Christchurch…
A video about the discovery of a historic tramline on North Avon Road. The video includes an interview with Brent Leersynder, a site engineer for SCIRT, and Steve Timpson, site foreman for SCIRT. The SCIRT team found the tramline while repairing the damaged wastewater system under North Avon Road in May.
Stopbanks around the lower Avon River.
A fence along the side of the Avon River near the Retour Restaurant has broken and is leaning towards the river. The photographer comments, "After the Christchurch earthquakes the land moved towards the river Avon and in a lot of places buildings and walls sagged down in the direction of the waterway".
Autumn tree in Christchurch around the Avon River.
Autumn tree in Christchurch around the Avon River.
Autumn leaves on trees along the Avon river.
By Fabian Bell The Avon is a lovely river. Of course I know that many people will say that it is no better than a ditch, &c. I pity their want of taste. Of course the stream is narrow and does …
Autumn leaves on the trees along the Avon river.
House across the Avon river, seen from Mona Vale.
House across the Avon river, seen from Mona Vale.
Shows a aerial representation of Christchurch's eastern suburbs with the course of the Avon River. The new river course spells the word 'munted'. Quantity: 1 digital cartoon(s).
An update on trout spawning in the Avon River and notes on the effects of seismic activity on physical habitat
Cracks on the steps around the footpath by the Avon river.
A stage being set up across the Avon River on Hagley Park.
The Avon river through Mona Vale where some punting rides depart from.
A video of Prime Minister John Key taking part in a tree planting ceremony on the banks of the Avon River in Christchurch. The trees were planted to symbolise the beginning of the rebuild of the Christchurch central city.
For many years the Heathcote-Avon estuary was the dumping ground for Christchurch's sewage. Then, in 2010, the wastewater was diverted well out to sea, via a long pipe. David Schiel from the University of Canterbury and John Zeldis from NIWA were investigating the effects of this diversion on the health of estuary when the 2011 Christchurch earthquakes happened, re-engineering both the estuary and their experiments.
Looking over the Avon River to buildings inside the cordon on Oxford Terrace.
Looking over the Avon River to buildings inside the cordon on Oxford Terrace.
Members of the public enjoying the spaces around the Avon river in the CBD.
Trees being cut down on the bank of the Avon, near the Student Health Centre.
Trees being cut down on the bank of the Avon, near the Student Health Centre.
Trees being cut down on the bank of the Avon, near the Student Health Centre.
Ducks still swimming in the Avon River, where most of the surrounding land is badly damaged.
The entrance to the West Avon building on Montreal Street. The photographer comments, "This very wonderful Art Deco heritage building in Christchurch had residents living in it until another visit from the building engineers re-re-checking for earthquake damage. Now it is fenced off and on the list for possible demolition".
The Avon and Heathcote Rivers, located in the city of Christchurch, New Zealand, are lowland spring-fed rivers linked with the Christchurch Groundwater System. At present, the flow paths and recharge sources to the Christchurch Groundwater System are not fully understood. Study of both the Avon and Heathcote Rivers can provide greater insight into this system. In addition, during the period 2010-2012, Christchurch has experienced large amounts of seismic activity, including a devastating Mw 6.2 aftershock on February 22nd, 2011, which caused widespread damage and loss of life. Associated with these earthquakes was the release of large amounts of water through liquefaction and temporary springs throughout the city. This provided a unique opportunity to study groundwater surface water interactions following a large scale seismic event. Presented herein is the first major geochemical study on the Avon and Heathcote Rivers and the hydrological impact of the February 22, 2011 Christchurch Earthquake. The Avon, Heathcote, and Waimakariri Rivers were sampled in quarterly periods starting in July 2011 and analyzed for stable Isotopes δ¹⁸O, δD, and δ¹³C and major anion composition. In addition, post -earthquake samples were collected over the days immediately following the February 22, 2011 earthquake and analyzed for stable isotopes δ¹⁸O and δD and major anion composition. A variety of analytical methods were used identify the source of the waters in the Avon-Heathcote System and evaluate the effectiveness of stable isotopes as geochemical tracers in the Christchurch Groundwater System. The results of this thesis found that the waters from the Avon and Heathcote Rivers are geochemically the same, originating from groundwater, and exhibit a strong tidal influence within 5km of the Avon-Heathcote Estuary. The surface waters released following the February 22nd, 2011 earthquake were indistinguishable from quarterly samples taken from the Avon and Heathcote Rivers when comparing stable isotopic composition. The anion data suggests the waters released following the February 22nd, 2011 Christchurch Earthquake were sourced primarily from shallow groundwater, and also suggests a presence of urban sewage at some sites. Attempts to estimate recharge sources for the Avon-Heathcote Rivers using published models for the Christchurch Groundwater System yielded results that were not consistent between models. In evaluating the use of geochemical constituents as tracers in the Christchurch Groundwater System, no one isotope could provide a clear resolution, but when used in conjunction, δ¹⁸O, δ¹³C, and DIC, seem to be the most effective tracers. Sample sizes for δ¹³C were too small for a robust evaluation. Variability on the Waimakariri River appears to be greater than previously estimated, which could have significant impacts on geochemical models for the Christchurch Groundwater System. This research demonstrates the value of using multiple geochemical constituents to enrich our understanding of the groundwater surfaces-water interactions and the Christchurch Groundwater System as a whole.
A digitally manipulated photograph of the badly twisted Medway Street footbridge. The photographer comments, "This bridge over the Avon River in Christchurch, New Zealand has been left in place since the first major earthquake back in September 2010. Graffiti artists or taggers are still leaving their marks on it even though it is nearly twisted at 90 degrees at one point".