Ashby Consulting have recently completed a new customised servicing depot for one of Auckland main bus companies, consisting of workshops, and panel shop, refuelling facilities, washing facilities and the companies new offices. Aaron Holland one of our chartered engineers got involved at the initial planning stages following the project through all the stages to completion dealing with all the civil works and infrastructure design required for the development.

The project presented some significant hurdles to overcome as the site was subject to flooding and overland flow, had an ecologically sensitive wetland on its boundary, contained large areas of contaminated soil with high ground water levels that were affected by the tides along with very low ground strengths that required a raft like pavement suitable for the large number of heavy vehicles.

The development involved multiple consents from Auckland Transport, Watercare and the Auckland Councils different departments. The consents ranged from a trade waste consent for the bus wash right through to an ITP consent detailing the specialised stormwater treatment requirements the site. The bus depot development was classed a high risk activity in relation to stormwater with the Auckland Council allowing only TP10 approved devices to be utilised previously. Due to the site constraints this was not a realistic possibility for the development and its location so Aaron worked through the issues of the site with the council and client and designed a stormwater system that consisted of grassed swales, upflow filters, smart sponges and oil separators which provided the necessary stormwater quality discharge from the site to satisfy everyone’s requirements.

Because of the site’s ground conditions a specialised asphalt pavement design was undertaken and implemented across the site which allowed some flexibility in the pavement to accommodate the significant variations in ground conditions across the site. Downers EDI, Highway Stabilisers, and JFC worked together with Ashby’s and provided the specialist input and construction techniques required to achieve a robust pavement.

“Although the bus depot development was a significantly challenging site, with numerous hurdles to overcome, the project was finished on time, and began operating with very few teething problems which was a credit to all parties involved.”