Livestock grazing: a natural tool for freshwater conservation?
23rd July 2025
Freshwater Habitats Trust Technical Director Penny Williams explains how low-intensity livestock grazing can be an effective management tool for ponds and other freshwaters.
People often assume that ponds should be fenced off from livestock and other grazing animals like deer. But when used appropriately, grazing can create and maintain the short vegetation and open, muddy conditions that many freshwater species need to thrive.
Low-intensity grazing by livestock is often overlooked as a conservation tool. However, our research consistently shows that grazed waterbodies typically have a higher conservation value than their ungrazed counterparts. This doesn’t mean that grazing is appropriate for all waterbodies or wetlands, but it can be an effective way to manage many freshwater sites.
Livestock and freshwater: ancient natural allies
Livestock affect freshwater habitats in two key ways:
• Grazing – by nibbling and tearing vegetation
• Poaching – the churning of wet ground by hooves
To understand why this matters, we can look to the geological past. A cow’s heavy hoofprint at the edge of a modern pond creates a patch of bare, wet mud – this is a process with very ancient roots. The first evidence of animals trampling near water dates back over 400 million years, to the Devonian period, when large reptiles began moving onto land but were still heavily dependent on water. By the Jurassic period, 200 million years later, poaching was so common that geologists even have an excitingly named dinoturbation index – to measure of how much muddy mess dinosaurs created on wet ground at the edge of waterbodies.
- Cattle on Horseshoe pond in Skipwith National Nature Reserve - North Yorkshire
Fast forward to the Pleistocene, and many of our modern freshwater plants and animals were directly evolving alongside large herbivores: the ancestors of deer, cattle and horses. And – like today’s animals – they needed very regular access to waterbodies to drink: grazing and trampling their margins and influencing the community structure here.
Given this deep history, it’s no surprise that many wetland plants – including some of our rarest – depend on poached, open ground. Species such as Brown Galingale, Coral Necklace and Starfruit, need bare, wet margins to establish. Many others – like Ragged Robin, Water Mint and our three species of water forget-me-not – thrive in the short vegetation created by the grazing and disturbance of large herbivores.
Today, we can replicate these natural processes with grazing by livestock like cattle or horses, or by allowing deer access to ponds.
- A pond poached by horses at the Water Friendly Farming demonstration site. This shows the effect of the bank angle on livestock access.
Four ways livestock benefit freshwater biodiversity
Our research shows that animal-grazed ponds tend to be richer in species and more likely to support rare plants and animals. Here’s how they help:
1. Controlling dominant plants
Grazing is a natural way to prevent tall, vigorous plants like Bulrush from overwhelming freshwater margins and shallow water. This allows a greater diversity of plant species to flourish, and in turn creates a more complex underwater architecture for different animal species to live amongst.
2. Letting in light
Excessive shade from trees and tall shrubs can limit the growth of freshwater plants. Grazing off willows and scrub before they dominate ponds keeps some margins sunny or with dappled shade – ideal conditions for many freshwater species.
3. Creating new habitat
Poaching creates bare, churned, muddy areas that many species can colonise – including uncommon wetland plants. In some cases, livestock may even help create new ponds through repeated trampling, which forms shallow depressions that fill with rainwater.
4. Supporting species dispersal
Livestock transport seeds in mud on their hooves or in their hair, helping spread plants between waterbodies and aiding colonisation of restored or newly created habitats.
Making grazing work: what to consider
There are important questions for land managers to consider before deciding whether or not to introduce grazing animals – and to work out some of the details.
1. Could grazing damage a site?
Grazing isn’t appropriate everywhere and needs to be tailored to a site’s conservation value and goals. Introducing grazing could potentially harm ecosystems that have developed for long periods without it, particularly where sensitive species are present. Although, in the wider countryside, outside nature reserves, serious damage is relatively unlikely.
2. Which animals are best?
Cattle and horses are ideal due to their size and grazing behaviour – they create deep hoofprints and will graze in shallow water. Sheep are lighter and graze margins rather than entering water, so can be less effective, but still beneficial.
- Gill Cathles a farmer in the Irfon catchment in mid-Wales has introduced low intensity grazing.
3. How much is too much?
There are no set guidelines for ideal stocking densities around ponds, because the impact of grazing and poaching varies with so many other variables such as the number of ponds, their size and bank profile, the time of year and stocking duration. In practice, good advice is not to worry too much unless a pond is becoming completely and permanently devoid of vegetation: both lightly grazed ponds and those with extensive muddy areas can support rare species and remain high-quality habitats.
4. What’s optimal?
To maximise freshwater diversity, it’s worth aiming for a mix of grazing intensities around waterbodies – including areas of heavily grazed and poached margins, lightly grazed areas, and everything in between. There are many ways to achieve this. Varied bank profiles or areas of low scrub will locally control access.
Consider livestock behaviour. For example, cattle will regularly patrol their field boundaries and shelter under taller trees. So, placing new ponds near these features encourages more regular grazing and trampling here.
At Thames Water’s Pinkhill site in Oxfordshire, we created some pools very close together to create ‘pinch-point’ corridors where cattle regularly pass. This heavily poached zone now sustainably support uncommon plants like Lesser Water-plantain and Tubular Water-dropwort.
- Pinch point between cattle-poached new clean water ponds at the Water Friendly Farming demonstration site.
5. Can fencing help?
Fencing can be useful if grazing pressure would otherwise be too high. Flexible options – like adding gates or using temporary electric fencing – will help ensure that there is still the potential for livestock access at some times of year. In general, we avoid simply fencing off half of a pond since it often results in extremes – with the fenced half completely overgrown, and the unfenced section a mud bath. Off-setting fences across ponds in different ways means you can create varied habitat. Our booklet created with UCL, Guide to the Restoration, creation and management of ponds: Bringing ponds to life includes a figure illustrating this (see p46 Figure 52).
Fencing may not be the only way to restrict access to parts of a site. In our River Irfon Catchment Project in mid-Wales, we’re currently working with farmers to trial cattle GPS collars to influence levels of livestock poaching without the need for fencing.
- Cattle collars are an alternative to fencing and are being trialed in the River Irfon catchment in mid-Wales
6. Nutrients, turbidity and veterinary medicines
It is often assumed that livestock will pollute ponds through their urination and defecation. In practice there is surprisingly little evidence for this. In semi-natural landscapes grazed ponds still remain low in nitrogen and phosphorus – nutrients that can cause major problems for freshwater ecosystems. In intensively farmed arable or improved grassland landscapes ponds are typically nutrient polluted, regardless of grazing. Livestock will undoubtedly add some nutrients, but they also remove them by grazing down wetland plants that would ultimately rot and release their nutrients into the water. There is even some evidence that grazing in these contexts may help maintain lower nutrient levels by limiting tree encroachment – preventing the input of phosphorus from decaying leaves.
Livestock can undoubtedly increase water turbidity – cloudiness – by trampling and sediment disturbance. However, unless turbidity levels become very high, the evidence to date suggests this does not appear to reduce the conservation value of ponds. A more significant issue may be that high levels of suspended silt will inevitably drop to the pond bottom, so heavily poached ponds may fill with sediment more rapidly.
Veterinary medicines, such as avermectins used for cattle worming, can be toxic to aquatic invertebrates in lab settings. However, they quickly bind to sediments and organic matter and are broken down by light. We still know very little about their longevity or ecological impacts in real-world conditions. More research is badly needed.
Success stories from the field
The New Forest is an internationally significant landscape for freshwater and supports many rare species.
This is largely down to the combination of its pristine, unpolluted water and a long tradition free roaming ponies and cows as a result of Commoners having the right to turn out their animals to graze. The depressions these animals create and the dung they produce help to provide the perfect conditions for rare and endangered plants.
As co-hosts of the New Forest Catchment Partnership we understand the vital role this traditional practice plays in maintaining the high-quality freshwater habitats in the New Forest.
- A cow grazing in the New Forest National Park.
Pinkhill Meadow in Oxfordshire is an example of how livestock are helping to provide similar effects in a site that was developed more recently in association with site owners Thames Water, and the Environment Agency.
We started creating new clean water ponds here in 1990 and the site is now recognised as an Important Freshwater Area, supporting around 20% of Britain’s wetland plants and freshwater invertebrates.
This sustainable management of Pinkhill Meadow is thanks, in part, to a small herd of Dexter cattle that now graze the site. Over the last few years, they have improved the edge structure of the ponds. We have used many of the techniques described above to encourage ‘differential grazing’, by creating pinch points and designing ponds with ‘front edges’ for heavier grazing and poaching: maintaining conditions for rare plants that would not otherwise survive.
- Intrepid cows grazing an island in Pinkhill Main Pond at Pinkhill Meadow in Oxfordshire.
Our use of grazing as a technique to manage high-quality freshwaters is not limited to ponds. For example, we are now introducing a small number of cows to Hinksey Heights alkaline fen in Oxford.
Initially, volunteers cut back scrub that has encroached on the fen so that rare species are now returning to and spreading out across the site.
Introducing cattle is important to support their work, helping to ensure that trees and scrub don’t – once again – swamp the site and risk us losing one of our most threatened freshwater habitat types.
- Ragged Robin growing at Raleigh Park fen where cattle graze.
Building the Freshwater Network
Natural processes like grazing and poaching have shaped freshwater habitats for millions of years. By replicating these with livestock, we can restore and maintain high-quality habitats today.
Like any management tool, grazing must be site-specific, well-planned and carefully monitored. But when done well, it can make a significant difference.
As we build the Freshwater Network, livestock grazing will be an important tool for creating and restoring thriving high-quality habitats across the landscape.
For further information:
Ponds, Pools and Puddles by Jeremy Biggs and Penny Williams. Collins New Naturalist, 2024.
The Pond Book: A guide to the management and creation of ponds. Freshwater Habitats Trust, 2018.
The geology of ponds: implications for their management today – talk by Penny Williams
New approaches to the management of ponds by Jeremy Biggs, Antony Corfield, Dave Walker, Mercia Whitfield and Penny Williams. British Wildlife, 1994.