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A pond in South Norfolk in the summertime.

M.Watson.

Ponds

A common feature of the British landscape, ponds can provide a welcome haven for all sorts of wonderful wildlife. Sadly, half of Norfolk’s ponds have been lost in the past 75 years. 

Most ponds are located within farmland, but they can be found throughout the landscape, including in gardens, villages, and towns. Ponds can be associated with many other habitats: throughout floodplains, within woodland and heathlands, and on grasslands or moors. 
 
Norfolk has around 23,000 ponds – more than any other English county. Most ponds are made by humans, with many created between the 17th and 19th centuries for marl or for clay, or as watering holes for livestock. 
 
The Norfolk Brecklands is also home to hundreds of ‘pingo’ ponds – ancient ponds that occupy ice depressions in the ground which were formed towards the end of the last great ice age. 

What are ponds?

A pond is a small area of still water that can vary in size from 1 square metre to 2 hectares. Ponds are usually freshwater but occasionally ‘brackish’ (a mix of freshwater and saltwater). Ponds are very different from rivers and streams because they don’t have moving water. They are also very different from lakes as they are small waterbodies, less than 80 metres across, which is around the point where the water in them stops ‘stratifying’ (the natural tendency to form distinct thermal layers i.e. cooler deep water, warmer water near the surface).  

Why are ponds important?

From aquatic plants, amphibians and invertebrates, to dragonflies, damselflies and mammals – ponds are an essential habitat for thousands of species, including an amazing two thirds of all freshwater species. 
 
Being a unique habitat for wildlife means that ponds are crucial on a landscape scale. They are regarded as vital stepping stones throughout the countryside, providing connections between different habitats. Ponds, and the connectivity between them, are crucial to species such as the great crested newt, which requires both freshwater and terrestrial habitat as part of its lifecycle. 
 
Ponds also provide wider environmental benefits thanks to their ability to hold water and reduce flooding, store carbon, and reduce pollution through water filtration. 

Threats to ponds

50% of Norfolk’s ponds have been lost in the past 75 years, primarily due to being filled in to allow the expansion of larger scale, more intensive agriculture. Now, ponds are threatened by land reclamation, widespread encroachment of trees and scrub, pollution, and invasive species. 
 
In our modern landscape, we face a challenge to ensure the survival and quality of our remaining ponds, and to restore lost ponds.

What are pingo ponds?

Also known as ‘kettle lakes’, pingo ponds are a very rare type of pond. There are dozens of pingo ponds in the Brecks – the largest density in the UK. Elsewhere in the UK, most pingos have been ploughed so they are a real peculiarity of Breckland.  

Pingo ponds were created at the end of the last ice age, and many have been left almost untouched since then. As the glaciers retreated, they left hard lenses of ice pressed into the ground, with soil over the top of them. When things warmed up it caused the lenses to melt, forming a depression in the ground filled with water – a pingo pond. ‘Pingo’ is the Eskimo word for hill. 

Assessing and restoring a pond 

If you have an existing pond on your land, assessing it with a view to future restoration is generally the best place to start. Existing ponds may already support valuable plants or invertebrates, which can be reinvigorated through sympathetic restoration. 

Conducting an assessment is a great way of understanding the current condition of your pond, the wildlife it’s supporting, and the potential the pond has for enhancement. This will help you decide on any management the pond needs, and how to prioritise between different ponds. Depending on your needs and your level of ecological expertise, you can undertake a simple, rapid survey or a scientifically detailed assessment. 
 
Norfolk Wildlife Trust and the Norfolk Ponds Project have developed a Rapid Pond Assessment which allows you quickly and effectively to understand basic parameters of your pond which will inform future management. 
 
It is also important to consider how your ponds fit within the landscape, and the contribution it can make to an ecologically connected network. 
 
Further details: 

Pond creation 

Before creating a new pond, consider if there are any existing ponds on your land that could be restored, in which case the above guidance can be followed. 
 
If not, the next consideration is the discovery of ‘ghost ponds’ which could be recovered and restored. A ghost pond is a former pond which has now been filled in. The digitalisation of historic maps is making it easier to locate ghost ponds, and then to consider their restoration potential. Restored ghost ponds can often reveal endangered or lost species and can be quicker to establish than brand new ponds. This is because historic layers of sediment, often still containing a viable seedbank, can be uncovered through skilled excavation of a ghost pond. 
 
If there are no existing or ghost ponds, then creating a new pond is a great way to establish valuable new habitat. You’ll need to carefully consider the location of your new pond: ensure it isn’t connected to any ditches or drains as this will help water quality. It’s crucial to check that the water table will support healthy water levels in your pond – a test hole can help determine the level of retained ground water. Please be aware that in some contexts planning permission will be required for the creation of a new pond. 
 
For more information on creating a new pond, visit the Freshwater Habitats Trust website. 

Useful links

Find out more about pond conservation:

Norfolk Ponds Project An innovative partnership to promote the conservation of Norfolk’s ponds.  Norfolk Ponds Project - guide
Ghost Pingos An exciting project to restore some of Norfolk’s special lost ‘pingo’ ponds.  Ghost Ponds - homepage