The 20th century - present
Gross pollution
Throughout the 20th century the exploitation of the river Don and its tributaries continued. Thermal pollution raised the temperature of the rivers, and acids, tar, oil and highly toxic heavy metals were common pollutants, along with the continued discharge of human sewage. Foam produced from detergents was the most obvious sign of pollution in the 1950s and 60s, often covering the river’s surface to a depth of several feet. Due to all these factors, the Don had the dubious honour of being named as one of the most polluted rivers in Europe in the 1980s. It’s waters ran yellow, as iron oxide continued to seep into them from abandoned coal mines.
From the 1980s onwards, the decline of heavy industry, upgrading of sewer infrastructure and the introduction of tighter regulations and legislation governing the natural environment have seen a steady improvement in river quality within the Don catchment.
Ecological recovery
In recent decades, as industrial pollution has receded the ecological health of the rivers has been given more and more precedence. Improving the health of river corridors has numerous benefits: for wildlife, for people and for the ecosystem services the river provides, such as reducing flooding and providing cooling to urban areas.
Numerous wildlife charities, such as the Wildlife Trusts, have created nature reserves along the Don and its tributaries. Regular ecological surveys by the Wildlife Trust, local councils and amateur groups have been documenting the gradual return to the catchment's rivers of many much-loved species of wildlife, such as kingfishers and otters. These species can now be seen right in the heart of urban areas, testament to the huge recovery that has occurred in the region's waterways in the last three decades.
Flooding
The Don has produced a number of notable floods. On the night of 26 October 1536 a sudden rise in the level of the river prevented the forces of the Pilgrimage of Grace from crossing the river at Doncaster, forcing them to enter into negotiations with Henry VIII's forces.
The Great Sheffield Flood, which occurred on 11 March 1864 following the collapse of the Dale Dike Dam, destroyed 800 houses, and killed 270 people.
The Don was also one of the rivers that flooded severely during the UK summer floods of 2007. Record levels of rainfall over a prolonged period resulted in flooding in Sheffield and Rotherham, in which two people died. In Sheffield, the areas around Wicker Riverside and Nursery Street were particularly badly affected, with millions of pounds of damage done to local houses and businesses.
In the Denaby Main/Mexborough area, the river rose and burst its banks onto the Doncaster road bridge, also flooding the railway tracks situated to the north of the river. The nearby canal overfilled, with some parts of the Don flowing into the canal. This resulted in a great increase in water volume, and lead to this combined body of water overflowing towards houses near Salmon Pastures.
What now for the Don catchment?
We are at an interesting period in the catchment's history. Climate change, urbanisation, public access and invasive species are all challenges that need reconciling with flood prevention, water management, ecological improvement and economic development.
The region's city councils have been implementing a policy of creating parks along the river valleys, putting recreation at the heart of river management. Local groups such as the Five Weirs Walk have helped put public access back on the political agenda.
Sheffield University's research is reflecting these challenges. Large, multidisciplinary research projects such as Urban River Corridors and Sustainable Living Agendas (URSULA) and Managing Adaptive REsponses to changing flood risk (MARE) has integrating different facets of river management, and taking a catchment level approach. Such multidisciplinary approaches are going to be vital for the management of the Don catchment in the coming decades.