Lake Whangape facts for kids
Quick facts for kids Lake Whangape |
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 Lake Whangape
Location in New Zealand
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| Location | Waikato District, Waikato region, North Island |
| Coordinates | 37°28′S 175°03′E / 37.467°S 175.050°E |
| Lake type | riverine lake |
| Primary inflows | Awaroa Stream (NB a different stream, with the same name, further south, flows into Lake Waahi) |
| Primary outflows | Whangape Stream |
| Catchment area | 310 km2 (120 sq mi) |
| Basin countries | New Zealand |
| Max. length | 7 km (4.3 mi) |
| Surface area | 1,450 ha (3,600 acres) |
| Average depth | 1.5 m (4 ft 11 in) |
| Max. depth | 2.7 m (8 ft 10 in) |
| Shore length1 | 29 km (18 mi) |
| Surface elevation | 5 m (16 ft) |
| Islands | Motukauere Is, Roaroa Is |
| 1 Shore length is not a well-defined measure. | |
Lake Whangape is a large, shallow lake in New Zealand. It is the second biggest lake in the lower Waikato River area. Its name might mean 'a large sheet of water'. Since the 1860s, the land around the lake has lost most of its forests. This has caused the lake to change from clear water with many plants to a murky lake full of algae.
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Port Waikato | Lake Opuatia | Rangiriri | |
| Glen Murray |  |
Waikato River | ||
 Lake Whangape  |
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| Te Ākau | Rotowaro | Huntly |
Contents
How Lake Whangape Formed
Lake Whangape is a type of lake called a lateral lake. It was formed when a natural wall, or levee, from the Waikato River blocked it off. This likely happened about 2,000 years ago. It was caused by rising sea levels and dirt from the Taupo Volcanic Zone.
Hot Springs Near the Lake
There are two hot springs and many small water seepages near Lake Whangape. They are along the Te Maire Stream, which flows into the Awaroa Stream. The Awaroa Stream then feeds into the lake. These springs are about 9 km west of the lake. Their water is very hot, ranging from 65°C to 93°C.
Scientists think these springs get their water from deep underground. The water might come from more than 3,000 meters below the surface. In the 1890s, people used to take boat trips to visit these springs. Today, the springs are on private land and are not open to the public.
History of Lake Whangape
The area around Lake Whangape was once home to the Ngāti Tipa people. In 1832, a battle happened near the lake during the Musket Wars. In 1843, a dispute over an eel trap at the lake's outlet was settled. Later, in 1866, the Ngāti Mahuta and Ngāti Tipa groups were given equal rights to catch eels there.
During the Invasion of the Waikato in 1864, the area around Whangape was hard for British troops to reach. This was because of the many swamps and thick bush.
In 1876, Whangape became one of five areas in the Raglan County Council. The government also built paths and roads to open up the land for settlement. By 1883, a track connected the Waikato River to the West Coast.
However, the roads stayed poor for a long time. So, the lake and its streams were used for transport. A company was even started in 1906 to carry goods by boat from Rangiriri. People also asked for eel traps to be removed from the streams. This would allow steamers to carry goods for settlers.
Lake Water Levels
The water level in Lake Whangape has changed a lot over the years. Between 1968 and 2000, it went up and down. Water from the Waikato River flows into the lake when the river is high. Since 1999, a special wall, called a weir, has kept the lake's water level from dropping too low.
Pollution in Lake Whangape
In the past, Lake Whangape was very clear. You could see plants growing even in the deepest parts. But in the 1890s, the native forests around the lake were cut down for farms. This led to more dirt and pollution entering the lake.
A report in 2006 said the lake's water quality was getting worse. Regular checks showed the water was very murky. There were also high levels of chlorophyll, which comes from algae. Between 2010 and 2014, more than half the water samples had too much blue-green algae. A health warning was even issued in 2020 because of this.
Wildlife in Lake Whangape
Parts of Lake Whangape and its surrounding wetlands are protected areas. They were made a Wildlife Management Reserve in 1986. This helps protect the animals and plants that live there.
Aquatic Plants in the Lake
In 1869, a survey found many different kinds of plants growing in the lake. These included quillwort, fennel pondweed, and red pondweed. However, by 1921, the lake was full of weeds. By 1958, most of the original plants were replaced by new, invasive species. These included Egeria densa and Elodea canadensis.
Later, in 1987, the plant beds in the lake shrank a lot. The water became even murkier. This was possibly due to waste from coal mines. High levels of dirt and algae in the water now block out sunlight. This makes it hard for submerged plants to grow back.
Fish and Other Water Life
Even with the pollution, 14 types of fish live in Lake Whangape. There are many native fish, like short-finned eels and longfin eels. Other native fish include whitebait, common bully, and grey mullet.
However, there are also many pest fish. These include koi carp, mosquito fish, catfish, and goldfish. Koi carp were brought to New Zealand in 1872. They now make up a large part of the fish in the lake. The murky water, possibly from mining waste or koi carp, affects what the eels and other fish eat.
Plants Along the Lake Shore
Many plants grow in the swamps around the lake. These include different types of grasses and herbs. Lake Whangape has the largest known group of a native sedge called Fimbristylis velata. Other important plants are also found there.
In 1871, the lake's edges were covered in plants like raupo, flax, and kahikatea trees. Some of these plants, like swamp māhoe, are still found west of the lake.
By 1991, only a small amount of raupo remained. Willows were a problem as early as the 1890s. Now, the shores are covered by crack and grey willow trees. Floating mats of American primrose willow and Amazonian parrots feather are also found along most of the lake shore.
A survey in 1991 found 541 different plant species. About 300 of these were native to New Zealand. Some rare or endangered plants also grow there. However, invasive weeds and cattle grazing are still a threat to these plants.
Birds Around the Lake
Fifty-six different bird species have been seen on and around Lake Whangape. The most common birds include black swans, Canada geese, and paradise ducks. You can also see grey ducks, mallards, and pukekos. Other birds like bitterns, herons, and fernbirds also live there.
Some birds have been introduced to the area, while others have disappeared. In 1870, mute swans were brought to the lake. By 1878, there were enough swans to send some to other places. Geese were also added to the lake in 1905.
Lake Restoration Efforts
Lake Whangape is a very important water body for restoration. Efforts are being made to protect it. About a third of the lake's edge has been fenced to keep cattle out. A project has fenced 4.5 km of the south shore. Over 20,000 trees have been planted there.
In 2017, the government gave money to help with this project. This money also helps control alligator weed, an invasive plant. This weed has been sprayed since 2002 to stop its spread. Spraying also happens for other weeds like yellow flag iris.
Boat Ramps and Access
There are boat ramps at Whangape Domain and Shuggs Landing. You can also reach the lake edge from Beverland Road. To stop the spread of alligator weed, which was first found in the lake in 2003, boats must be cleaned before and after using the lake.
