The winter of 2023 and early 2024 has been particularly wet with the Met office saying that 2023 was the 6th wettest year since 1836¹. Add to this that 2023 was the second warmest year on record (just behind 2022)1 and we can really see the impacts climate change is having on our weather. If you have driven anywhere in the Wye and Lugg valleys this winter you will have seen vast areas lying underwater. 

In a previous blog we talked about Natural Flood Management and the importance of slowing the flow of water. A lot of Natural Flood Management takes place high up in the river catchments on smaller tributaries and we use lots of small interventions to create an overall impact. However even with all of these interventions flooding downstream is inevitable. 

As rivers move through the landscape their behaviour depends on the landscape around them, as they flow through steep-sided valleys the river will be forced to remain within the confines of that space. As the landscape opens up and becomes flatter the river can spill out flooding the low lying areas. Floodplains are a natural process and are vital within our landscapes, for the health of rivers, the benefits for wildlife, for agriculture and for the protection of communities downstream. 

Floodplains and agriculture 

The very nature of floodplains means that they can be really important within our agricultural systems. As rivers move through the landscape they collect sediments and nutrients, these are then deposited on the land increasing the fertility of the floodplains. Taking an extreme case it is the floodplains of the river Nile that ensure the countries along its bank have a productive agricultural system; loss of those floodplains drastically impacts on the land’s productivity².  

In the UK traditionally floodplains would be used either as pasture for livestock grazing through the drier months of the summer and autumn or managed as floodplain meadows. Managing them as a hay meadow means that the farmer benefits from both the midsummer hay cut and the grazing space through late summer and early autumn for cattle or sheep. The floodwaters then naturally restore the nutrients removed by the hay cut without the need for artificial fertilisers.  

Floodplain meadows can sustain a rich diversity of wildflowers and grasses, with the Floodplain Meadows Partnership reporting up to 43 species per m² in some cases³.  A diversity of plants can have many health benefits for livestock and may improve the value of the hay crop taken from the meadow. It is the specific management of these sites, including managing the movement of the water, that maintains these diverse plant communities. Traditional management practices date back to the Domesday book. 

The grazing of large herbivores, in particular cattle can also help to improve the diversity of both plant and invertebrate species on floodplain meadows. The disturbance of the ground can create opportunities for plant species less able to compete with grasses. A combination of hay cuts and livestock grazing is key to the ongoing management of these meadows. 

Floodplains and wildlife 

Floodplains have rich opportunities for wildlife both when they lie underwater and when they are dry.  

The management practices on floodplain meadows mean that they support a great variety of plant species, and can support nationally scarce species including snake's-head fritillary and narrow-leaved water-dropwort. Lugg meadows on the edge of Hereford is a good spot to see the snake's-head fritillaries in spring.  

This abundance of plant species also leads to an abundance of invertebrates. The nectar-rich flowers of these meadows provide a vital feeding ground for a variety of bumblebees, hoverflies, moths and beetles. With pollinator numbers struggling in recent years the meadow habitats of these sites becomes ever more important.  

Winter floods provide feeding grounds for migratory wildfowl and waders, including grey geese, wild swans, shoveler and teal, whilst in the summer the grasslands become ideal nesting spots for ground nesting birds like curlew and skylark. Loss of floodplain meadows has in some cases resulted in local extinctions for some breeding species³.  

Floodplains create foraging opportunities for otters and water vole, whilst we haven’t recorded water vole at our Lugg Meadows reserve there have been a number of records of otter on the site. Otters will use the rivers both for commuting through the landscape and as a food source. During periods of flooding these can both be interrupted and floodplains can provide a safe way for otters to continue to move through the landscape. 

Floodplains and climate change 

As our weather becomes increasingly erratic the role of floodplains will become ever greater. Over the last winter we have seen river levels remain consistently high, with the county’s floodplains inundated on a regular basis. Protecting our floodplains so that they can continue to function is vital not just for the benefit of the wildlife that use these floodplains but also for the protection of our communities that border the rivers.  

Healthy floodplains with a good cover of vegetation can store vast quantities of water preventing this from continuing to flow downstream. Floodplains covered in vegetation can prevent soil erosion during flood events and helps to remove nutrients from the water course helping to keep our rivers healthy. They can provide vital breeding grounds for birds and foraging opportunities for a range of invertebrates and mammals. They can also continue to function as a vital part of our agricultural systems, providing hay and pasture for livestock. 

References 

1.2023 was second warmest year on record for UK - Met Office 

2. Nile River (nationalgeographic.org) 

3. Floodplain Meadows - Beauty and Utility A Technical Handbook.pdf