Stay safe when visiting lakes, waterways and waterfalls

There are wonderful waterside places to explore in our National Park, but they can be dangerous as well as beautiful. Whatever activity you're planning, it's a good idea to check the latest conditions. A sparkling mountain stream that’s normally a delight to paddle in can become a raging torrent after a night's rainfall.

Take extra care after rain

Heavy downpours often wash the Park's characteristically reddish brown soil into the waterways. Unless you're an expert, keep well clear of water that is coloured brown or red – it's a sign of a waterway swollen by rain. The one exception to this is the Monmouthshire and Brecon Canal where narrowboats often stir up mud from the bottom, even on the sunniest of days! 

Water height

Avoid wading across rivers - this can be extremely dangerous. Rivers are often fast flowing and much deeper than they look. The flow and depth of water can vary widely from day to day.

If you're going canoeing or fishing on the River Wye or the River Usk, check the webcams on the Wye and Usk Foundation website ( for the latest water levels. 

There's also an excellent guide to river levels the Environment Agency website ( 

Wind speed

On lakes and reservoirs, strong winds can produce short, sharp choppy waves. Experts may welcome these conditions, but novice and intermediate sailors and windsurfers may struggle. For wind speed and general weather information, see the Met Office website ( 


Frozen lakes and sculptural waterfalls may look beautiful, but when ice is spread thinly over a deep, cold lake or reservoir, it can be a deadly trap for the unwary. If water appears to be frozen, don't trust it to take your weight. There's only one sensible suggestion: keep off.

Wild swimming

There are no formal facilities within the National Park for wild swimming . Even strong swimmers have been known to get into difficulties because of unfamiliar currents, underwater obstacles or the effects of very cold water – the water is always cold, even in hot weather. Don't jump or dive into unknown waters.   Please note that you should not swim in reservoirs or the canal - you can access the Wye at Glasbury Bridge and the Usk at Castle Meadows in Abergavenny 

The River and Lake Swimming Association video below offers generic advice about staying safe in water:


Avoid wearing trainers, mules or sandals on our waterfall paths as these don't give enough grip on slippery rocks and uneven ground. Wear walking boots or trail shoes instead. Look out for steep drops and keep away from the edge of banks and ledges. There are sudden cliff edges around the waterfalls and river banks can be unstable.

General advice

Supervise children at all times. Even shallow water can be dangerous.

Read any signs you see – they may be telling you about specific hazards.

Follow the Waterways Code as recommended by the Canal and River Trust (