Water Quality
None of the rivers in the Lower Trent and Erewash are currently achieving ‘Good’ overall status under the Water Framework Directive (WFD). All water bodies are failing on chemical water quality, with only 4 out 83 achieving ‘Good Ecological Status’. Reasons for not achieving good vary, but a mix of agricultural impacts, industrial and road run-off, sewage pollution, mining legacy and historic river modifications, mean that the overall health of the river in this catchment is failing.
Sewage Pollution
In 2021, data submitted to the Environment Agency reveals a total of 6,984 sewage spills. Such spills can be caused by blockages and overwhelmed sewer systems. Overloading the river with nutrients and pollutants these can have a detrimental effect on wildlife.
Invasive Non-Native Species
Signal Crayfish, Himalayan Balsam, Floating Pennyworth, Quagga Mussels, Japanese Knotweed and Giant Hogweed are some of the species that use the Trent to spread. As all tributaries ultimately make their way into the Trent, the lower stretches of this catchment, and the canals they are connected to are all particularly vulnerable to invasive species.
Mining
Historical mining has introduced pollutants and heavy metals to the Trent. Pollution from mines comes from the underground workings and waste materials spread on the land. These historic, redundant mines, which contain heavy metals can leech into the Trent’s watercourses. This water can be contaminated with zinc, cadmium, lead and iron. Minewater can have detrimental impacts on the species and habitats of a river which can impact kilometres of river downstream.
Agriculture
Diffuse pollution, topsoil run-off and point-source pollution put continuous pressure on the Trent. Phosphorus and nitrates, in particular, tend to overload the river with nutrients, suffocating aquatic plants and the communities depending on them.
Barriers to fish passage
There are a number of large structures that provide a block to fish passage on this stretch of the Trent. Many smaller structures also exist on tributaries requiring water to flow in a constrained way and also blocking aquatic species. Though the excellent Colwick fish passage project is underway, work is required on the other major Trent weirs or the benefits of upstream fish passage projects will be reduced, especially for migratory species.
Atlantic salmon
The salmon’s capacity to overcome obstacles and navigate back to its spawning ground is a journey that has shaped the Trent catchment. Man-made obstacles have impeded its journey for over 100 years, but successful reintroduction programmes, weir removal and fish passage easements have opened up parts of the catchment for the Salmon run once again.
Great Crested Grebe
The Great Crested Grebe – in spring this elegant water bird impresses with its capacity to carry its young on its back. Feeling most at home in the water, this excellent diver can be found in the nature reserves lining the Lower Trent.
European eel
The European eel has one of the longest migration journeys of all the freshwater species in the UK. The eels spend most of their adult life in freshwater, before returning to their spawning grounds in the Sargossa Sea. In the Trent catchment, the 60-80 cm long eel are usually found in our smaller tributaries.
