By Daniel Collins

The flooding that Christchurch experienced on Wednesday was extreme, leaving many houses flooded and roads closed. To build a better understanding of how vulnerable different parts of Christchurch are to flooding in the future, particularly following the earthquakes, we would like your help.

If you took any photos at or near peak water levels anywhere in Christchurch during Wednesday morning or early afternoon, please send them to NIWA (floodphoto AT niwa.co.nz)* with the street address and time, and with the subject “Flood”.

We will use the images to help identify how high the waters rose across the city. This will help us improve our models so we can provide better flood risk maps in the future.

* The NIWA email is once again working. Sorry for any inconvenience.

Update 16 June 2014: The results are in.

Dr Daniel Collins is a hydrologist and water resources scientist.