What is a Spate River? Everything You Need to Know

Spate rivers have been at the centre of many studies for numerous years now. They are also a hot topic for both on water or near water sports such as fishing, canoeing and paddling. A lot of the articles you read about spate rivers are interlinked with fishing topics, we will take a look at the reasons why a bit later. There is a lot to learn and talk about so let’s get started.

A spate river is a largely rain-fed, fast-flowing river. These types of rivers are both fast-rising and fast falling. The source of spate rivers begins high up, usually in mountains or hills which attributes to the fast flow.

There is a lot more to spate rivers as we will now explore. We look into exactly what a spate river is, other river types, the process of rivers rising and falling, and we take a look at some of the different spate rivers in the UK.

What is a Spate River?

The term spate river derives from the word ‘spate’ which in British terms is described as “a fast flow, rush or outpouring”. The origin of the word is unknown but it is believed to have been in the Middle English period (1150 to 1500) and was used by the Scots and the Northern English. Following this, a spate river is a term used to describe a river where the flow is very quickly affected by rainfall. Spate rivers are thought to be the hardest to fish in due to these sudden rises in water levels.

Generally, these rivers have their origins high up which is the reason they are susceptible to sharp rises in water levels when it rains. If there is no rainfall locally or higher up at the river’s source then you can expect river levels to quickly fall.

Spate rivers can be dangerous due to the unpredictability of the sudden rise in water levels. It may be raining at the river’s source but not locally, and this rainwater will quickly gather momentum as it comes downhill. There have sadly been many accidents due to the unpredictability of spate rivers and even the more experienced have been caught short. Rivers can be described as spate if the water levels rise and fall quickly. Spate rivers vary hugely when it comes to flow, height, colour, and topography.

River beds are formed from two natural processes – erosion and deposition. Put simply, what accumulates on the river bed comes from land surfaces as the flow of water brings them down. During fast flows of water, these items won’t settle – once the spate is over debris will settle creating the river bed. Materials making up the river bed can include sand, rocks, silt, weeds and organic materials.

Fast flowing water has the power to move an amazing number of heavy items such as large rocks. This means the height and river bed formation can alter drastically during a spate.

Different River Types

Now let’s take a look in more detail at some of the other river types and what differentiates them from each other.

Spate Rivers

Most of the water is made up of rainwater running off the land. How quickly they rise or indeed fall is dependent on the quantity of rainfall both locally and at the river origin. The water is less clear during times of rainfall making it hard to fish in.

Freestone Rivers

These rivers make up a large majority of the free-flowing rivers and they have their source high up. The flow is caused by rainfall or snow melting and little passages are created which then flow into larger passages before flowing into the base of the river. They are called freestone rivers due to the water flowing over gravel and rocks. Freestone rivers eventually flow into the sea.

Rain-Fed Rivers

The source of these rivers start up high and the rain or snow creates small channels known as Rills. These Rills grow in size as more water gets added which form larger channels known as Gullies. In time these Gullies form the river. The temperature of rain-fed rivers fluctuates greatly in comparison to spring-fed rivers.

Chalk Streams

Arguably these rivers offer the most beauty due to their crystal clear waters. Chalk streams are mostly found in Southern England and there are only approximately 200 of them worldwide. It is a spring-fed river. These chalk streams were formed from crushed seashells at which point Southern England was under the sea. The chalk effectively filters the water which makes them so clear and pure.

The Rise and Fall of Spate Rivers

The rise and fall of rivers come down to rainfall or the lack of rainfall. When there is a lot of rainfall the water levels will rise. This can take people close to the river by surprise as it may not be raining on the actual river itself. The rainfall can come from way up in the mountains which is why they can be quite hazardous to the unseeing eye.

Snowfall can also affect the water levels as the snow melts and is a contributing factor to the water cycle. Ice and snow account for a lot of the water availability in colder climates. Rapidly melting snow has its dangers as it can potentially lead to landslides and a lot of loose debris falling.

River water levels subside during drier weather spells when there is no excess water topping them up. Therefore the rise and fall of rivers can be influenced by seasonal factors and typically will rise more in the winter and early springtime.

Of course, there are factors which will have some impact on how much the rivers will rise and fall. For example, it will depend on the type of precipitation, the amount that falls and just how long these downpours last for. It can also depend on the direction of the wind at the time and how well moisturised the ground is before the wet weather. Flatter topography will mean the flow of water won’t be as fast.

If the ground is very dry then it will soak in a lot of the moisture as it flows downwards. But well-saturated areas will soak in the water so will stop this infiltration. Of course, the speed flow of the water is determined mainly by the slope in the landscape. The steeper the flow runs, the faster the river will fill up.

When rivers are low during dry periods you will get a lot of debris accumulating at the sides of the river such as leaves, twigs, and rubble. As soon as there is precipitation this debris falls into the water which will give it a dirty appearance.

Why Is Fishing Affected By River Levels?

Fishing success depends wholly on the water conditions. The more experienced fishermen will be excited by an incoming storm because they know this is when fish are more active. Runoff created from downpours creates great fishing opportunities because with this runoff comes worms and other insects that the fish will source. While the water is rising and through to its peak makes for perfect fishing conditions.

When the river gets back to normal levels your chances of having a successful fishing trip will be reduced. This is because the fish will become less active again due to changes in the water pressure.

UK Spate River Examples

River Wharfe

Based in Yorkshire, this river source begins in the Yorkshire Dales National Park (Beckermonds). It’s the 21st longest river in Britain at 65 miles long.

See current River Wharfe Levels here.

River Swale

Again based in Yorkshire, this river’s name is derived from the Anglo-Saxon word Sualuae meaning “rapid and liable to deluge”. The source of this river is situated in Birkdale.

See current River Swale Levels here.

River Ure

Situated in North Yorkshire, this river runs for 74 miles before it meets with the River Ouse. 1025 is the earliest recording of this river which was then called River Earp. Historians believe this name should have read as Ear P, P represents the old English letter Wynn (water).

See current River Ure Levels here.

River Feshie

Located in the Cairngorms National Park, the River Feshie is renowned for contributing towards the fastest flowing river in Scotland – the River Spey. The source begins in Glenfeshie Forest and is joined along the way by various Burns.

River Halladale

This is 15 miles in length and flows into the Pentland Firth, and is located in Sutherland. Its source begins in the hills of Forsinard and during and after heavy rainfall make it a popular fishing spot.

To Conclude

We have taken a look in detail at what constitutes a Spate River and what characteristics ultimately set it aside from other river types. We’ve spoken about its unpredictability and somewhat dangerous nature during heavy rainfall. Spate Rivers are popular for walkers, fishermen, canoeing, and paddling but lots of caution is required to remain safe. We’ve looked at the factors which cause the rise and fall of Spate Rivers and the impact this has.