Today I struggled to wake up. I was pretty tired, so I guess I must not have had a good sleep. I woke up at 7:30am and had a lazy start. I made myself eggs, cheese, and ham on toast for breakfast, served with a cup of coffee.
My first stop today was Hells Gate, which I tried to visit yesterday. Hell’s Gate is a geothermal attraction that has the world’s largest mud volcano, the largest hot waterfall in the Southern Hemisphere, and about 30 hot pools. It reminded me a lot of my trip to Iceland, but also in a different way. Iceland had pools that were more blue/green colour in hue, and these one’s were more black/yellow in colour. It all has to do with the amount of sulphur, and the type of effluent. I opted out on a mud bath because I was going to visit some other geothermal attractions, and wanted to save my money for those.
After visiting Hells Gate I drove to the next geothermal attraction that I wanted to visit called Waimangu Volcanic Valley. Waimangu is the only geothermal system in the world whose surface activity can be traced down to an exact day, in this case June 10 1886. An extremely violent volcanic eruption occured, causing a series of craters and allowed geothermal fluid already present underground a direct passage to the surface of the earth. I took a one and a half hour walk through the valley and saw the beautiful Southern Crater, Frying Pan Lake, and Inferno Crater. Southern Crater was formed during the 1886 eruption and is about 50 metres deep. The crater isn’t active, and is thus a cold pool except for some warm ground and some small mud pools at its north-eastern end.
Frying Pan Lake was formed on April 1 1917 when Echo Crater erupted, causing a deep and enlarged crater that quickly accumulated water. The lake is fairly acidic, with an average pH level of 3.5, and is fairly hot reaching boiling temperatures at the surface of the lake. There is a small river that flows from the north-eastern side of the lake.
My personal favorite was Inferno Crater, which is a pale blue lake that is highly acidic, with a pH level of 2.1, and a temperature of 80 degrees Celsius. The lake follows a complicated rhythmic cycle of shallow recessions occurring every few days, followed by deeper recessions at longer intervals. It’s common behaviour is to overflow for two to three days, recede about eight metres for about fifteen days, partially refill over three to four weeks, oscillate for a while, and then overflow again. White silica deposits make where the overflow level is.
At the end of the walk a bus can pick you up, but the bus only runs every hour or so. I was lucky and arrived only a few minutes before a bus arrived.
After catching a bus to the top I was in need of some food because it was way past my lunch time. I had an apple and an orange, as well as a ham and cheese sandwich.
I wasn’t sure what to do next so I checked the GPS provided with my camper, as well as Google. I got quite a bit of information that interested me. My first stop was Ohaaki geothermal power station. I wasn’t allowed to enter, but I took some nice photo’s of the plant. When I was in Iceland you were allowed to have geothermal power plant tours at their power plants. I went on two with my father when I was there last year. Ohaaki is unique because it is the only power station of its kind in New Zealand, with a 105 metre tall natural draft cooling tower. The other power plants all use fan coolers, or water cooling. The power plant was originally constructed in 1989 and had a generating capacity of 104 MW, but over the years this has declined to 65 MW, due to a decline in the steam field. This is common with geothermal power plants. A way to mitigate this is to re-inject the effluent back into the ground when done with it, or to use a blended cycle co-generation, where smaller turbines run off intermediate and low pressures leftover after the main turbine has extracted what it can from the steam.
My next stop was Aratiatia Rapids, which had a short five minute walk to a lookout to see the rapids. Technically the rapids are not always prevalent due to the dam constructed for the Aratiatia hydro-electric power station in 1964. The dam construction meant that no water flowed over the rapids, but several times per day the dam gates are opened which restores the rapids to normal operations. These rapids are also used by local companies for white water rafting.
After visiting Aratiatia Rapids I headed towards Taupo Lake, which is where most of New Zealand’s geothermal power stations are located. I stopped at Wairakei geothermal power station and took a few photos. This is the largest geothermal power station in New Zealand at 161 MW. It uses all the latest technologies such as effluent re-injection, and blended cycle co-generation. I also took a photo of the bridge next to the power station, because I thought it looked nice.
The last stop of the day was Haku Falls, which are fast and furious. While I was photographing the falls a jet boat was blazing around at the bottom with some pretty thrilled customers screaming and laughing.
It was time to find a place to sleep for the night. I picked a great spot right in front of Taupo Lake on the north shore. I had a beautiful view of the sunset, a few hundred ducks as company, and even free wifi!