Event report – YPG Wellington Field Trip

They say you can’t beat Wellington on a good day… but as Young Professionals descended on the capital, a southerly front sweeping rain up the South Island met a northerly high-pressure zone and ground to a halt above Wellington. The heavens opened, the cricket was cancelled, but the YPs soldiered on.

We all met in the Meridian / Dam Safety Intelligence (DSI) office on the Wellington waterfront at 9, and after a brief introduction by Cameron Paintin on the plan for the day and health and safety (it was wet so beware slips, trips and falls), Dan Forster of DSI launched into a presentation on the history of the dams we were to be visiting that day. The Korokoro and Woollen Mills dams were the first concrete gravity dams built in New Zealand, and the inspiration for larger concrete gravity dams built around the country. The Woollen Mills dam supplied pressurised water to the Woollen Manufacturing Company in Petone. We also learnt about the Birchville Dam in Upper Hutt which was a concrete arch dam that had undergone recent upgrades to replace dewatering valves for reservoir drawdown.  All three dams are operated by the Greater Wellington Regional Council (GWRC), who have place high priority in dam safety, public safety and infrastructure resilience. These dams offer no financial production, water supply or flood retention but hold significant public amenity and heritage value.

We then continued the trek down the Korokoro River valley for 40 minutes to Woollen Mills Dam. This was the heaviest rainfall for the day and listening to the park rangers tell stories of the flooding when the valley was flooded from bank to bank wasn’t too reassuring. At the Woollen Mills dam we saw the repairs to the dam foundation and spillway, the new fish passage, and the steep abutment overhanging the spillway where rocks had previously broken off and damaged it. It was a difficult site to access and would have been a logistical challenge when undertaking repairs.

We met the bus at the bottom of the valley at the site of the previous Woollen Manufacturing Company and decided to skip seeing Birchville Dam, as everyone was soaking wet. Instead we moved on to the next item on the programme, the visit to Brewtown in Upper Hutt and the Boneface Brewery. There was some tenuous link between water supply dams, brewing, and beer, but it was more a great opportunity to drip dry, warm up, and have a chat to our fellow YPs. After a couple of hours, we boarded the bus again to take us back to Wellington City and the airport.

I’d like to thank everyone who attended the trip despite the bad weather and thank the NZSOLD Management Committee for funding the transport and DSI for funding the lunch and providing the meeting room. Also, thanks to Dan Forster for putting together the presentation and Bronek and the two Jeremys of GWRC for taking the time out of their day to show us around their dams.

Cameron Paintin