The River Tees is located in the North East of England.
The Tees’ source is located in the Pennines close to Cross Fell, at 893 metres above sea level, where roughly 1200mm rainfall occurs annually, although some areas have 2000mm. It is 100km long.
In the upper course of the river is a famous waterfall known as “High Force” as well as a gorge accompanying it. High Force is 21m high, and has been formed over millions of years. The top of the waterfall is made from a very tough rock called “Winstone”. Below the winstone lie layers of limestone, sandstone and shale. The river erodes rapidly through the rocks at the bottom, due to their being relatively soft, and eventually, once a large enough overhang has been created, the rocks collapse downwards under gravity, and create a sheer rock face for the waterfall to flow down. 20m^3second^-1 runs across the winstone rock.
High Force also creates potholes nearby. Smaller rocks are rotated by the river’s flow after being trapped in depressions in the rock and eventually wear downwards to make round, deep holes.
Close to Yarm, the Tees forms large meanders, which have formed ox-bow lakes. Flooding has caused the formation of levees.
During the last ice age, water was locked up on land, meaning that sea levels were lower. When sea levels rose, the river was rejuvenated, meaning that it tried to achieve a natural long profile again (of a long and mostly gentle curve from the source to the mouth). The adjustments created knick points, most notably High Force, which is eroding back to form a new long profile, but this process has also caused an estuary to be made as the sea flooded the original mouth of the river.
Parts of the estuary area are SSSIs (Sites of Special Scientific Interest) (which are carefully managed due to holding unique ecosystems such as seal sands), or are just generally important for the local wildlife, notably migratory birds and seals.
The flat estuary area is also attractive to large industries due to the flat land, and the fact that the river is quite wide, allowing container ships to their premises easily.
The Tees takes large meanders through its middle course. Directly, it is 30km from Darlington to Teesmouth, but along the river it is 75km. Several miles have even been cut off from the original course to shorten boat journeys.
The Tees is used for water-sport, for the protection of wildlife habitats, for farming in the fertile alluvial soil, and for big industries, as well as for residential use.
Cow Green Reservoir: (Upper course). The highest reservoir in the area. The river supplies water (high water quality) and also helps flood control.
Sheep Farming: (Upper course): The land in the upper course is too steep for machinery and too acidic for crops, so is instead used for sheep.
Tourism and conservation: (Upper course). The moorland, High Force, shooting etates, and a nature trail at Windybank Fell all atract visiots, as do the Pennine Way, and the rural villages of the area. Tourism provides jobs and helps stimulate the economy, but also causes congestion, litter, and overcrowding.
Tees Barrage: (Lower course). Opened in 1995 for sport and flood control.
Seal Sands: (Lower course). The mudflats around the river mouth are very important for seals and for migratory birds.
Urban and Industrial use: (Lower course). Large towns such as Stockton and Middleborough and Teesdale support large industries such as chemical industries, ships, steel-making and engineering.
ICI: (Lower course). Petrochemical industries based at Billingham and Wilton are placed to receive North Sea oil.
Shipbuilding has been replaced by oil platform construction.
The management of the Tees has various aims:
- Reducing flooding
- Improving the water supply
- Improving the water quality
- Improving navigation
- Providing recreational opportunities
Reservoirs, such as Cow Green and Grassholme have been built.
In the 19th century, cut-offs were built around Stockton to straighten the river, and flood protection schemes have been built recently at Yarm. There is also a water sports complex at the Tees barrage.
Yarm used to be a huge port town, enclosed by a meander. However, it was difficult for boats to travel 18km inland on the Tees. Commerce was broken off by a bridge closer to the sea at Stockton. The Victorians saw too many meanders and built a 3km long straight channel.
The estuary used to be a marsh area but is now almost entirely artificial. Heavy industries reside on the reclaimed estuary mud. There is space and access to open water, so it is used by North Sea oil and petrol companies, and by a nuclear power station. 90% of the raw materials for these are carried from outside because the channel is deep enough for the them.
(Image sources: https://co-curate.ncl.ac.uk/river-tees/ http://www.banksgroup.co.uk/new-residential-development-plans-approved-for-unique-bowesfield-park-site/)
(PS: I promise that I won’t do so much explaining of processes once I’ve explained it once!)