Ponds 

Pond Creation

Ponds can be made in several ways. The simplest is to simply dig a hollow and allow it to fill with rain water. A pond like this is not likely to hold water for much of the year. Ponds which dry up in the summer are called ephemeral ponds and have their own specialised collection of species.  When they dry up, it kills many species, especially fish. Many fish are predators on other animals (e.g. amphibians) and can completely wipe other species out.  When a pond dries up and kills the fish species which can tolerate dry conditions or which only spend part of the year in the ponds can still survive.  Ephemeral ponds can therefore be important for many species.  

                                                      

 

 

 

 

 

 

To make a pond hold water for longer it is necessary to line it.  The easiest and cheapest way is to use a polythene or butyl liner.  However these are easily vandalised and so are often not suitable for public spaces.  A better alternative in these cases is bentonite or other clay.  This are less prone to being punctured and bentonite will even seal itself if damaged.  This however is more expensive to install and is a job best carried out be specialist contractors. 

CEL have established many ponds in gardens, schools and open spaces throughout London.  Small pond are done by ourselves but for larger or clay line ones we work with contractors who specialise in this type of work. 

Pond Management

Ponds, like most habitats, need periodic management. The amount of management often depends on the size of the pond and where it is situated. Small ponds and those under trees which get a lot of leaf fall tend to silt up quite quickly. Larger ponds trend to do this too, but more slowly. This means that ponds tend to dry out over time as the silt builds up. Also if dead vegetation accumulates the ponds can become deoxygenated and stagnant.

To stop this it is necessary to dredge ponds. Small ponds can be dredged by hand using rakes but larger ones may need large machinery and mat even need to be drained top get access. CEL are able to carry out management on ponds using hand tools, small digger and machinery or by working with specialist contractors on large projects.

Floating islands

Many water birds like to nest and roost on islands where they are safer from predators and other disturbance.  Floating islands are a simple and cost effective way to provide these safe havens. Floating island are also attractive features and are popular with site visitors. 

This photo shows a floating island installled by CEL in Forest Lane Park in Newham.  It was quickly used by the local coots and has proved very popular with birds and visitors alike.

Floating islands can be constructed in many ways but the one CEL has found most effective is using plastic piping as the flotation section with a metal grid supporting coir mats.  These are light weight and are simple to construct in any shape required. The coir matting can be either pre planted with aquatic plants or plants from the margins of the pond can be transplanted into them.

Establishment of aquatic and emergent vegetation

Aquatic and emergent vegetation are essential to make a pond good for wildlife.  Submerged  vegetation helps to stop a pond becoming stagnant by oxygenating the water, many species feed on aquatic plants and emergent bank side plants provide shelter and cover for many species.  It is very important to make sure not introduce any non-native pond plants (e.g. New Zealand pygmy weed or parrots feather) which are often sold in garden centres for ponds.  These will take over the pond and choke out any other plants.  CEL are able to source and plant native plants such as reeds,  submerged oxygenating and other pond plants