Sadly, your correspondent was crook and did not attend the site visit. Many thanks to the professionals for their time and effort.
I can highly recommend having a look at the Ōtāhuhu Station case study published by the Auckland Design Manual.
Update: I’m delighted to be able to share with you some pictures and thoughts by Yi (Sophie) Huang, a civil engineering student who attended the visit. Thanks Sophie!
The most interesting part for me was the stormwater collection system and the water treatment pond.
At the station, there are two small rain gardens. The one we saw is approximately 5-7 square metres. There are plants, grass and flowers above the ground surface. Beneath the soil, the bed is deeply filled with sand and other materials which have a very good permeability, to absorb the stormwater. The storm water is collected underneath the rain garden then discharges through a stormwater channel to the water treatment pond. After several processes, the water is good enough to release into the wetland. We did not have a chance to see the water treatment pond, because the traffic was busy and it was too dangerous to walk there.
The stormwater system was built to reduce the possibility of rainwater being contaminated by oil underneath Ōtāhuhu Station. Furthermore, one of the iwi consultants was very concerned about water quality: she strongly suggested that it would be a good idea to include an on-site water treatment pond. Sarah Zwart, of Jasmax, said that if the iwi had not persisted in the idea, the on-site water treatment pond might not be there.
There were several difficulties involved in the construction process of this project. Firstly, constructability: several things did not go as planned. There was a problem with the piles, and this had to be solved. The schedule and money at that time were very tight. Tony Berben, of Aurecon, said “most of the time we think on our feet. There are always problems we did not expect; we had to find solutions for each of them.”
Secondly, time and money were constrained. Joshua Hyland, of AT, said it was very important to make sure the right materials were delivered on time. Because of the tight schedule and budget, they didn’t have time and money to reorder and wait for the right material to be delivered.
We saw all the art works from the case study. They look simple, amazing with deep meanings and were not expensive. For example, at the station entrance, there is an x-shaped pattern, the purapura whetū mahau [by Tessa Harris of Ngā Tai Ki Tāmaki]. Joshua Hyland said it represents the past and future, and ancestors.
I learnt so much and was amazed by the two hour site visit. On the train back to the CBD, the professionals gave us tips on finding jobs, networking with people and how to be better engineers. They are super-friendly people and professional in their field. Moreover, I made amazing friends through the trip as well.