River Cleddau facts for kids
The River Cleddau (Welsh: Afon Cleddau) is made up of two rivers in Pembrokeshire, west Wales: the Eastern Cleddau and the Western Cleddau. These two rivers join together to form the Daugleddau estuary. This estuary then becomes the very important natural harbour known as Milford Haven.
The name Daugleddau means "the two Cleddaus." The word Cleddau comes from the Welsh word cleddyf, which means 'sword'. This name might describe how both rivers cut deeply into the land of Pembrokeshire, like a sword.
Contents
Eastern Cleddau River
The Eastern Cleddau (Welsh: Cleddau Ddu, meaning 'black') starts in the hills of Mynydd Preseli. It flows southwest through a wide, open valley. Near Gelli Hill, another river called the River Syfynwy joins it.
The river then flows south through a deep valley, passing places like Llawhaden. It becomes tidal at Canaston Bridge, which is the lowest point where you can cross it. The Eastern Cleddau estuary meets the Western Cleddau estuary at Picton Point. This river is about 34 kilometres long, with about 7 kilometres being tidal.
Western Cleddau River
The Western Cleddau (Welsh: Cleddau Wen, meaning 'white') has two parts that come together. The eastern part starts near Fishguard and flows southwest. The western part starts in Llanreithan and flows east. These two parts meet at a place called Priskilly.
The combined river then flows through Wolf’s Castle. Here, it enters a truly amazing place called the Treffgarne gorge. This gorge is 90 metres deep and cuts through very hard volcanic rocks. The river then flows south to Haverfordwest, where it also becomes tidal. The tidal part of the river widens into a deep, flooded valley called a ria. It joins the Eastern Cleddau estuary at Picton Point. The Western Cleddau is about 40 kilometres long, with about 9 kilometres being tidal.
Why the Valley is So Big
The Western Cleddau is a special type of river called a misfit stream. This means the valley it flows through is very deep, even though the river itself is quite small.
This big valley was formed at the end of the last Ice Age. At that time, the River Teifi was much larger, filled with melting ice water. An ice dam stopped it from flowing into the Irish Sea. So, it flowed west through other river valleys and then south along the path of the Western Cleddau. This powerful ancient river carved out the large valley we see today.
Historically, the tidal part of the Western Cleddau allowed ships to reach Haverfordwest. It was also important for shipping coal, which was dug up from mines near the river.
Daugleddau Estuary and Milford Haven
The Daugleddau estuary is where the two Cleddau rivers meet. It stretches from Picton Point all the way to the entrance of the harbour. This estuary is a huge, deep, and wide natural harbour. It has many bends, which help protect it from strong winds and rough seas. This makes it an excellent place for ships.
Because it is so deep, it can easily hold very large ships, even giant oil tankers. This made it an important centre for the oil industry starting in 1957. For a short time in the 1970s, it was the second busiest port in the UK for the amount of goods it handled. The Daugleddau and its smaller tidal branches are all known together as Milford Haven. This part of the waterway is about 27 kilometres long.
History of the Estuary
In the past, the estuary was very important for reaching castles like Pembroke and Carew by sea. These castles could then be used as supply bases, for example, during the Norman invasion of Ireland.
During the early Industrial Revolution, the estuary was used to ship coal and limestone. There was also a small fishing industry operating from villages like Pill and Angle. In 1790, the new town of Milford was built, and a large herring fishing industry grew there. At its best, Milford became the UK’s seventh largest fishing port. However, as fish became harder to find close to shore, and the docks were too small for bigger fishing boats, the fishing industry almost completely stopped.
Milford was first planned to be a naval dockyard for the navy. But in 1814, this project was moved to Pembroke Dock, on the other side of the estuary. The town of Neyland was also built on purpose, this time by the Great Western Railway, to be a place where ships could sail across the Atlantic Ocean. Later, many of its shipping jobs moved to Fishguard.
River Life and Nature
Both parts of the Cleddau River are special because of the many different kinds of plants and animals that live in their waters. Human activities have not changed these rivers much, so they are very natural.
The rivers are home to otters and many types of fish, including Lampreys. Parts of both rivers have been named as SSSIs. This means they are very important because they have healthy populations of otters, bullhead fish, and different kinds of lampreys (river, brook, and sea lamprey). These areas are also special for their different river habitats, including beds of underwater plants like water-crowfoot, and the plants that grow along the riverbanks.
The Cleddau rivers are also a Special Area of Conservation. This is an even higher level of protection. It means they are important for:
- The European bullhead fish.
- Different types of lampreys (river, brook, and sea lamprey).
- Otters.
- Rivers with floating plants, often dominated by water-crowfoot.
- Active raised bogs (wetlands).
- Alder woodlands that grow on floodplains.
Additionally, some land near a small stream that feeds the Eastern Cleddau, called Gweunydd Blaencleddau, is also a Special Area of Conservation. This area is protected for habitats like:
- Wetlands fed by calcium-rich spring water, called alkaline fens.
- The southern damselfly.
- The marsh fritillary butterfly.
- Wet heathland with plants like cross-leaved heath.
- Very wet mires, which often have a wobbly, 'quaking' surface.
- Blanket bogs, which are large areas of peatland.
