The two reports below provide a summary of conclusions and recommendations from a series of investigations commissioned by the Christchurch City Council and Environment Canterbury. The full reports can also be accessed by clicking on the green links within the summary reports or via the links further down this page.

Note that the focus of this work has been on the Avon River/Ōtākaro, Heathcote River/Ōpāwaho, and the Avon-Heathcote Estuary/Ihutai because these waterways have been most badly affected by the earthquakes.

The investigations were undertaken by NIWA, EOS Ecology, Aquatic Ecology Limited and the University of Canterbury.

Read the summary reports

Ecological effects of the Christchurch February earthquake on our city rivers

The 22 February 2011 earthquake affected Christchurch’s rivers and streams through the production of liquefaction sand/silt, bank slumping, uplift of streambeds, and input of raw wastewater. Studies looked at aquatic ecosystems in the Avon River/Ōtākaro and Heathcote River/Ōpāwaho to find out the extent of these changes and to assess what could be done about them.
Read the low resolution version of the summary report (pdf 685 kB)

Ecological effects of the Christchurch February earthquake on our city estuary

The 22 February 2011 earthquake affected the Avon-Heathcote Estuary/Ihutai because of changes in land height and the shape of the estuary bed (its bathymetry), because of large areas of liquefaction throughout the estuary, and because of the input of raw wastewater. Studies quantified the degree of change and effects on ecosystems.
Read the low resolution version of the summary report (pdf 397 kB)

Read the full reports

Rutherford and Hudson 2011. Effects of wastewater overflows on oxygen and ammonia in the Avon and Heathcote rivers. (pdf 2.12 MB)

James and McMurtrie 2011a. Christchurch February Earthquake: Effect on aquatic invertebrates. (pdf 3.82 MB)

James and McMurtrie 2011b. Christchurch February Earthquake: Effect on freshwater fish of the upper Avon River. (pdf 2.01 MB)

McMurtrie 2011. Christchurch February Earthquake: Effect on invertebrates of the lower rivers. (pdf 2.90 MB)

Taylor and Blair 2011. Effects of seismic activity on inaka spawning grounds on city rivers. (pdf 3.06 MB)

Hicks et al. 2011. Mapping earthquake induced topographical change and liquefaction in the Avon-Heathcote Estuary. (pdf 1.62 MB)

Zeldis et al. 2011. Effects of the Canterbury earthquakes on Avon-Heathcote Estuary/Ihutai ecology. (pdf 1.37 MB)

New reports

Research is ongoing on the state of our surface waterways following the earthquakes and the following reports have been produced after the above summary reports were completed.

Barr et al. 2012. Effects of the Canterbury earthquakes on Avon-Heathcote Estuary/Ihutai macroalgae (pdf 2.01 MB)

Alex James and Shelley McMurtrie 2012. Post-Quake Ecology of the Lower Avon River (pdf 3.55 MB)

Taylor et al. 2012. An update on trout spawning in the Avon River, and notes on the effects of seismic activity on physical habitat. (pdf 4.61 MB)