River Severn is a unique river in the United Kingdom. Anyone who has spent an entire season navigating this river has the ability to identify multiple changes in the river’s mood. It is not uncommon to cast off on a slow, sleepy stretch of the River Severn in Worcester in the morning and by the afternoon, your stretched section of the River Severn is now quick, brown and several feet higher due to rainfall in the Welsh Hills. Reading the changes and how the changes impact your boat is a skill all River Severn boaters need to develop.
Why Severn behaves unlike other rivers
Like many other rivers, the Severn develops different personalities compared to other rivers. Severn does not have weirs like canals, rather, the Severn is a working river that extends its catchment area deeply into the Welsh Midlands. Rainfall in the Cambrian Mountains can reach the River Severn in Gloucester, which means the weather upstream can impact the soon to be local weather. Always think of the lag. A long week of sunny weather and fair conditions do not guarantee fair weather in the local conditions if rain has recently fallen upstream.
Understanding the Environment Agency gauges
The Environment Agency publishes real time river level data for gauging stations on the Severn from Bewdley and Worcester to Upton, Haw Bridge, Saxons Lode and beyond. It’s worth getting into the habit of checking the nearest gauge to your mooring or planned route before setting off. Most boaters learn the local gauge “normal’s” fairly quickly and a reading half a meter outside the “norm” should prompt some serious consideration of whether to go out.
The Environment Agency does publish free flood alerts and warnings in a range of colors from yellow being lowest concern through to red being the highest level of concern. A yellow alert is not a trip canceling indicator but more a prompt to check the conditions and be prepared to change the plans.
Reading the water itself
Gauges and alerts are useful but nothing beats the ability to “read the river.” A few things that more experienced Severn boaters look for are:
Gauge readings and alerts are crucial, but really nothing beats gaining an understanding of the river. Some of the things more experienced boaters look for are:
Speed of flow. Watch how fast fixed objects, like moored boats, posts, or buoys, pass by from the riverbank. The fastest current you have likely seen is often the best early sign of how quickly rising water will impact the area.
Bank markers. Many sections of the river Severn have either informal or formal bank markers, on either lock, bridge, or mooring posts. By looking at the water line on a bank marker you are familiar with, you can find out more by simply looking instead of crossing the river to see what a downstream gauge is reading.
Debris and floating objects. When you see objects or large logs or pallets, debris or objects which are normally considered too large to float, it shows that the water level is rising and it will be harder or unsafe to travel by boat in the river.
Actions to take when water levels are increasing
When you see signs of rising water, it is the right time to check mooring lines and properly set fenders to prevent boats from hitting under a structure, or overhang.
In case you start to see adverse conditions and are traveling by boat, you should move your boat to the closest safe location to moor instead of trying to continue to your original destination. Rising water levels can create a challenge in controlling the boat during maneuvers in the Severn and make lock and weir actions very hard and dangerous, which also helps to avoid an adverse situation.
Some locks do stop passage altogether when certain levels or currents are reached, both because this is safer for boaters and modes the lock gates. Lock keepers are incredibly useful if you’re ever lost.
Becoming superstitious
Honestly, this doesn’t need to get complex. Checking the Environment Agency gauge is quick. Look at what the sky looks like and how much recent rainfall there has been. Finally, watch the water and you usually cover yourself. In a season or two, most Severn boaters develop a sixth sense and learn what is normal and what isn’t, and what might cause problems.
It’s important to know how the river can change, but you have to learn to deal with that and not get frustrated. It helps that a quick check before you set off will add only a small amount of time to your day and makes the trip much safer.