The GRANTHAM URBAN RIVER AND WETLANDS PLAN is an overview of Water Framework Directive related issues and opportunities in the River Witham corridor through Grantham. It brings together the plans, ideas and aspirations of a diverse range of groups and organisations with an interest in the River Witham and the riverside. It is not an Environment Agency Plan, instead it is intended to be a catalyst for the development of new partnerships to deliver mutually beneficial projects and encourage the pooling of resources to achieve greater results. Delivery is ongoing and groups and organisations are welcome to bring forward new projects at any time.
The GRANTHAM URBAN RIVER PLAN is underpinned by 5 overarching objectives which apply throughout the length of the river.
River Habitat Enhancement and Restoration There is huge potential for instream and marginal habitat improvements. New gravel riffles, woody habitat and marginal wetlands will greatly benefit wetland biodiversity and improve the Ecological Status of river, a requirement of the Water Framework Directive. Particular emphasis should be placed on Safeguarding Protected and Notable Species, e.g. white-clawed crayfish, water voles, otters, brown trout and bats, aided by the production of distribution maps. Some outline opportunities have been identified on the Plan Map, although further, more detailed, survey work will be required to determine the full range of opportunities. Some improvements could be implemented in the short term, but if it is feasible to remove some of the structures, e.g. the low weirs (see Objective 2), then in-stream habitat should be planned in conjunction with these schemes to ensure that they function under the new hydrological conditions. Habitat enhancement schemes must be carefully designed to ensure that they do not increase flood risk.
Improving Hydromorphology and Fish Passage There are numerous weirs and sluices along the river that, to varying extents, impound the watercourse, limiting the morphological and ecological potential of the river and obstructing fish movement. Fish passage issues need to be addressed at all these structures. Fish passes can be retrofitted to some structures, but where possible structures should be removed altogether which would not only allow fish movements, but also restore the natural bed gradient. Coupled with in-stream habitat enhancements, e.g. channel narrowing and gravel introduction (see Objective 1), this would greatly increase the ecological value of the river, with the added benefit of reducing flood risk by increasing floodplain capacity.
Improving Water Quality by Tackling Potential Pollution Sources Good water quality is essential to the health of the river environment. Issues associated with road run-off (either directly in to the river or via tributary streams e.g. the Mow and Barrow Becks), foul and combined sewer discharges and contaminated land must be addressed to ensure the success of Objectives 1 and 2.
Tackling Invasive Non-Native Species Invasive Non-Native Species (INNS), e.g. Himalayan balsam, knotweed species and giant hogweed, are degrading the quality of riverside habitats, and species, such non-native North American Signal Crayfish, could adversely affect native species populations in the future. A survey and mapping exercise should be undertaken to identify the extent and locations of INNS, followed by the development and implementation of a strategic plan to tackle the identified issues. Anglers and contractors undertaking in-river works should be encouraged to exercise appropriate biosecurity measures to prevent the introduction of non-native species must be addressed There is an opportunity for volunteers, e.g. RiverCare and angling clubs, to participate in the survey work and the practical management of some species e.g. Himalayan balsam.
Developing Riverbank Management Plans Public open spaces linked by riverside paths make the River Witham through Grantham unusually accessible and this experience is enjoyed by many people. The successful RiverCare Group shows how much local people value the river. However, initial consultation on this plan identified lack of bank management, littering and graffiti to be ongoing issues and a lack of riverside seating was also highlighted. There is particular concern about how the river banks are being managed adjacent to public paths, in particular the amount of bramble encroachment. Riverside trees are also an issue. The costs of regular management/maintenance can be high so it is recommended that South Kesteven District Council, RiverCare and Environment Agency explore the issues and develop a prioritised Riverbank Management Plan which, in addition to bramble management, addresses tree protection, maintenance and planting, and measures for tackling invasive non-native species (see Objective 4). This would also be an opportunity to explore the littering, graffiti issues and need for more seating.
© 2019 Lincolshire Rivers Trust