River Tees Overview and Course Features
Starting high up at Cross Fell in the Pennines at 893m above sea level, the River Tees flows 137km to reach the North Sea. This mountainous source receives a whopping 2000mm of rain annually, which explains why the river has such a long history of flooding problems.
The upper course shows all the classic mountain river features you'd expect. Here you'll find dramatic V-shaped valleys carved by vertical erosion, plus interlocking spurs where the river weaves between hard, impermeable rock formations. The star attraction is High Force - the UK's largest waterfall at 21m high, created where hard whinstone meets softer sandstone.
As the river reaches its middle course near Darlington, everything changes. Lateral erosion takes over from vertical erosion, creating the meandering patterns and oxbow lakes that are perfect exam material. The large flood plains here are incredibly fertile, making them ideal for intensive farming.
Key Exam Tip: Remember the three-course model - upper (vertical erosion), middle (lateral erosion), lower (deposition). The Tees demonstrates this perfectly!
The lower course becomes completely flat with massive mudflats and sandbanks forming the estuary. Natural levees have formed here, and this area now hosts one of Britain's largest container ports, showing how geography shapes human activity.