Omanawa Falls Power Station facts for kids
Quick facts for kids Omanawa Falls Power Station |
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 Location of Omanawa Falls Power Station in New Zealand
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| Country | New Zealand |
| Location | Bay of Plenty |
| Coordinates | 37°50′46.6″S 176°05′21.3″E / 37.846278°S 176.089250°E |
| Purpose | Power |
| Status | Operational |
| Construction began | 1914 |
| Opening date | 1915 |
| Owner(s) | Tauranga Borough Council Tauranga Electricity Trustpower Tauranga City Council |
| Dam and spillways | |
| Type of dam | Weir |
| Impounds | Omanawa River |
| Reservoir | |
| Total capacity | None |
| Power station | |
| Name | Omanawa Falls Power Station |
| Operator(s) | Omanawa Falls Hydro Limited |
| Commission date | 1915 |
| Type | Run-of-the-river |
| Hydraulic head | 109 ft (33.22 m). |
| Turbines | 1 |
| Installed capacity | 0.2 MW (270 hp) |
| Annual generation | 1.5 GWh (5.4 TJ) |
The Omanawa Falls Power Station is a special kind of power plant that uses the flow of a river to make electricity. It's located on the Omanawa River in the Bay of Plenty region of New Zealand. Built in 1915, its main job was to provide electricity to the nearby town of Tauranga. What makes it really unique is that it was the very first underground power station in the Southern Hemisphere!
Contents
History of the Power Station
Starting Up: How it Began
The Omanawa Falls Power Station officially started working on August 28, 1915. A man named Henry Richmond Climie, with help from Mr. H.M. Millar, got the station ready. Just over a month later, on October 2, 1915, the town of Tauranga got electric street lights for the first time! This replaced their old gas lamps. The electricity from Omanawa traveled to Tauranga through special power lines.
Building the power station was a big project for Tauranga. It cost a lot of money, but it brought modern electricity to the town. The first person in charge of running the station was E.L. Gossett. When he went to serve in World War I, W. Milne took over his job.
Growing Bigger: Meeting Demand
After only two years, people in Tauranga needed more and more electricity. The power station's original machines weren't big enough anymore.
Around this time, a gold mine called Muir's Reef opened nearby. The mine owners wanted electricity to power their equipment. This extra need for power, plus the growing demand in Tauranga, convinced the council to make the power station much stronger. They decided to increase its power output from 200 kilowatts (kW) to 800 kW.
To do this, they bought a new, larger generator from the USA in 1921. They also found a powerful turbine from Switzerland that had been used at another gold mine. This huge turbine had to be taken apart and moved about 100 kilometers (62 miles) on horse-drawn wagons because no truck was big enough! The heaviest part took five days to move, needing ten horses on steep hills.
The power station building was made larger to fit the new equipment. This new generator produced a lot of power for many years.
Over time, the ownership of the power station changed. Eventually, in 1997, the Tauranga City Council sold it to a company called Trustpower.
Closing Down and Reopening
Trustpower decided to close the Omanawa Falls Power Station on July 29, 1998. They then gave it back to the Tauranga City Council. After it closed, the station suffered from damage by vandals.
However, in 2007, a man named Michael Davis, who loved old hydroelectric sites, decided to save it. He got a long-term lease from the Tauranga City Council and spent a lot of money to fix up the power station.
Even though the old generator couldn't be used for making power anymore, it was kept and is now on display. The original turbine, however, was in good shape and was repaired. A new, modern computer system was also put in place to control everything. The station started making electricity again in November 2008!
How the Power Station Works
Location and Water Flow
The power station is built right next to the Omanawa Falls, which are about 35 meters (115 feet) high. Water for the station is taken from the Omanawa River just above the falls. A small wall, called a weir, helps direct the water into an intake area. This area has a steel screen to stop large pieces of debris from entering.
From the intake, the water flows through a tunnel that is about 1.8 meters (6 feet) high and 1.2 meters (4 feet) wide. This tunnel runs for about 180 meters (590 feet) to a large concrete pool called a forebay. The forebay has a special spinning net that catches leaves and other small bits to keep them out of the turbines.
The Powerhouse and Equipment
From the forebay, a large pipe called a penstock drops about 27 meters (90 feet) straight down into the powerhouse. The powerhouse itself is carved into the side of the ravine at the bottom of the falls. It has a concrete wall with windows and a door big enough to bring in all the machinery.
Inside the powerhouse, the water from the penstock turns a large turbine. This turbine is connected to a generator, which is the machine that actually makes the electricity. After the water passes through the turbine, it flows out through another tunnel into the pool below the falls.
To get to the powerhouse, workers used to have to go down a long access tunnel with 250 steps!
The Omanawa River is fed by springs, which means it has a steady flow of water all year round. This allows the power station to produce a constant amount of electricity without big changes due to seasons. Rules are in place to make sure enough water still flows over the beautiful Omanawa Falls.
Original Electrical Setup
When it first opened, the power station had two generators that together could produce 200 kW of power. Each generator was connected to a turbine that spun at 750 revolutions per minute (rpm). The electricity was then sent through transformers to increase its voltage to 11,000 volts (11 kV) for long-distance travel.
The main electrical controls were on a large switchboard made of marble. This board allowed operators to control and monitor the power being produced.
The electricity then traveled about 21.7 kilometers (13.5 miles) on power lines supported by strong wooden poles. These lines carried the power to a substation in Tauranga, where the voltage was lowered for use in homes and businesses.
Current Operations
Today, the Omanawa Falls Power Station uses a single turbine that spins at 375 rpm. After its refurbishment, the station is now fully automated, meaning it runs mostly by itself. It produces 200 kW of power and generates about 1.5 gigawatt-hours (GWh) of electricity each year. This power helps supply homes on Omanawa Road and further up the Kaimai area.
