Piako River facts for kids

The Piako River is an important river system in the North Island of New Zealand. It flows through low-lying areas and eventually empties into the Firth of Thames.

This river is one of the two main waterways that drain the Hauraki Plains. It is also the most important river in the Matamata-Piako District. Along its path, it flows past the towns of Morrinsville and Ngatea.

The Piako River is about 100 kilometers (62 miles) long. It runs from south to north, covering much of the central and western Hauraki Plains. Its journey starts near Hinuera in the south. It then flows north, ending up in the Firth of Thames. This is about five kilometers west of the town of Thames.

Where the Piako River Starts

The Piako River has two main starting points, or stems.

The Main Stem

The first and main stem collects water from the northern Te Miro-Tahuroa hills. It also gets water from the Pakaroa Range. The Piakonui and Piakoiti Streams are important rivers that feed into this stem. These streams, along with the smaller Toenepi Stream, join together south of Kereone. This is where they officially become the Piako River.

The western slopes of these hills are drained by the Waitakaruru Stream. This stream joins the Piako River near Morrinsville. As the Piako River continues north, many small streams add to its flow. These streams come from the eastern side of the Hangawera Hills.

The Waitoa River Stem

The second stem is the Waitoa River. It begins near Piarere. The Waitoa River collects water from the Hinuera Flats. It also drains the wide southern Hauraki Plains. This stem then meets the Piako River in a large wetland. This wetland is known as the Kopuatai Peat Dome, located northeast of Tahuna.

The upper part of the Piako River also gets water from the eastern side of the Hapuakohe Range. This comes from several small streams that flow down the range.

Farming and Water Quality

The Piako River system has been greatly changed by a lot of dairy farming. Because of this, scientists have studied the Toenepi Stream. This small stream is part of the Piako River system. They use it to research how intense farming affects water quality. They also work to develop better farming methods.

Protecting the Piako River from Floods

People have done a lot of work to protect the Piako River area from floods. This work started as early as 1906. Since the 1930s, many flood protection measures have been put in place. These efforts are especially important north of Paeroa-Tahuna Road. They also protect the Kopuatai Peat Dome.

How Flood Protection Works

The flood protection system includes several important parts:

• They make the main river and smaller streams wider and clearer.
• There are 170 kilometers (106 miles) of stopbanks. These are like walls built along the river to hold back water.
• There are 59 floodgates. These are special gates that can be closed to control water flow.
• There are 32 pump stations. These pumps help remove excess water from flooded areas.

Even with these measures, the river flooded again in 2017. A plan from 2018 aims to make the stopbanks stronger. It also includes creating more diversion ponds to hold floodwaters.

Levels of Protection

The flood protection system is designed to offer specific levels of safety:

• It provides 100-year protection from high tides. This means it should protect against tides that happen once every 100 years.
• It offers 50-year protection from Piako River floods. This protects against floods that happen once every 50 years.

The Piako River Bridge at Ngatea

The first Piako River Bridge in Ngatea was built a long time ago. It opened in 1917. In the early days, people traveled mostly by sea, river, or canal. As roads started to be built, a bridge over the Piako River became very important. It helped create a main road route between Auckland and Tauranga.

A lot of work has been done to fix and strengthen the river banks. This is because in winter, the river often causes flooding. This flooding affects the low-lying Hauraki Plains.

See also

In Spanish: Río Piako para niños