Common frog by Katrina Martin
A well-designed and well-sited pond can quickly become a rich wildlife haven, attracting not only those species that we think of as aquatic, but also many other animals that come to ponds to drink water or to find food.
By creating pond mosaics and wetland complexes that mimic natural systems, it is possible to provide a mix of permanent, semi-permanent and seasonal pools to maximise variety of habitat.
Creation versus restoration
There are an estimated 22,000 ponds in the Suffolk countryside, with some parts of the county having five times as many as the national average. But, with 70% of ponds in a degraded and neglected state, the role that restoration has to play in Suffolk should not be overlooked. This is especially true given the speed with which ponds respond to management.
It is also worth remembering that pond creation is at a disadvantage to restoration in that there are no existing aquatic communities to revive.
Location
Choosing an appropriate site for your pond is probably the most important decision you can take when creating your pond and will have ramifications on how good it will be for wildlife.
Clean water
The location of a pond will determine the quality and quantity of its water source. Whilst those ponds with fluctuating water levels and that dry out occasionally are very valuable (and often excellent for amphibians as top fish predators die), ponds that dry out annually are less so, and are often quickly taken over by invasive vegetation and tend to concentrate pollutants in the ever-decreasing waterbody.
It’s best to avoid locations where the landuse in the pond catchment area is intensive. Woodlands, heath and rough grasslands generally make better sites than arable or grassland where the ground is regularly disturbed or is likely to be high in nutrients. Avoid all sites where fertilisers or pesticides are applied and could run off.
If you intend to put a pond on ex-intensively farmed land it could be worth soil stripping in obvious water catchment areas.
Areas that receive run-off from roads, tracks, houses, yards or spoil heaps are also generally unsuitable.
Avoid drain arable ditch, steam or drain inflows into ponds as the water is usually quite polluted and likely to deposit polluted or enriched sediments. The extra silt could shorten a pond’s lifespan by centuries. With surface water seepage, the water is likely to be of a far better quality if the water is coming from less fertile or unfertilised ground.
Think carefully before locating ponds near to public paths or be prepared to design ways of mitigating against impacting on wildlife.
Planning permission and archaeology
Pond creation for anything other than livestock watering will usually require planning permission from your local district or borough council.
Ensure that your pond design looks appropriate in scale and design within the local landscape character and does not harm archaeological interest. If in doubt, take advice from the Trust and Suffolk County Council’s archaeological or landscape departments.
Make sure your pond will hold water
Ponds dug in areas naturally holding water, usually with clay bottoms, are generally the most robust. Things like polypropylene liners can be used but they will have a limited life and are expensive.
Be strategic
Ponds created close to existing wetland habitats are colonised more quickly and by a bigger range of species. If possible place your pond where uncommon or rare species occur to help them create a stronghold.
Sometimes it is more important not to dig at all. Avoid destroying an already-valuable habitat to create a new one. This includes not only the ground to be dug, but also where the spoil is spread. Flower-rich grassland has obvious value, but areas of scrub, rough grassland and low-lying hollows can also be important habitats. Formerly intensively farmed land is more likely to be expendable, though it is worth consulting the Trust if in doubt.
By agreement with a local farmer and depending on the soil type, you may be able to spread pond spoil on agricultural land at a certain time of year. Sometimes you may be able to sell or give away the spoil to someone local.
Pond design
Designing your pond should be fun, but there are many features and types of pond that need to be considered to maximise the benefit to wildlife.
Pond mosaic
Where possible try and create a network or mosaic of ponds. A wetland complex is much more likely to sustain wildlife than an isolated water feature and can be dug in all but the tightest of spots. The most valuable wildlife ponds are at least 25m square, but smaller ponds can be valuable.
Instead of digging a pond of 15m by 15m, consider creating a small complex comprising of a main pond of 10m by 10m, with around seven other smaller ponds ranging from 10m by 5m down to 0.5m diameter.
Try and make sure shallow and deeper pools are not connected to each other except at exceptionally high winter water levels.
The complexity allows opportunities for a bigger range of species. Pond depth and size are major factors determining community types. Provide mix of permanent, semi-permanent and seasonal pools to maximise variety of species.
An irregular outline looks more natural and provides a longer edge but avoid over-complicating the design. After all, the complex will require more maintenance.
Allocate the majority pond area to very shallow zones
Most wildlife is found in water less than 5cm deep, so it’s worth thinking about how you can vary your pond’s bank and its underwater profile.
The shallows which are underwater in winter, but dry in the summer are known as drawdown zones and are areas of high biological diversity – good for resting dragonflies, hunting flies and other wildlife. Incorporating a series of hummocks and hollows in the shallow drawdown zone maximises water edge zones as the pond water recedes.
Whilst shallow ponds of up to just 1m of water depth are excellent for wildlife, they are often impractical as they are colonised very quickly by invasive vegetation. So in small ponds especially, try and create a sharp drop-off to deeper water (to 1-2.5m) to prevent rapid growth over the whole pond by invasive plants and avoid disruptive removal of vegetation.
If the banks are likely to be grazed, subtle variations in topography will produce plant-community differences. If grazing is not likely, tall emergent plants will eventually dominate so subtle contours will be less useful.
Underwater stones and logs half in and half out of the water provide good cover and microhabitats for many aquatic species.
Try and avoid islands as they can encourage ducks, which have a detrimental effect on the wildlife value of the pond.
Further advice
For more information or to get in touch with Suffolk Wildlife Trust or phone 01473 890089.
For more detailed toolkits on making ponds in the countryside visit Freshwater Habitats Trust’s Million Pond Project