Pond types

Ponds made by damming up the chalk stream

• Most of the ponds at Abbey Farm are formed by damming up a chalk stream using a sluice or earth banks (‘bunds’). Examples include:

  • the two ponds in front of the bird hide
  • a pond in the public access area created by holding water up using an earth bank

• When the springs stop flowing the water levels in these ponds starts falling. Some ponds continue to dry up until they lose all surface water in late summer and autumn. These ponds then become suitable for plants that specialise in colonising bare mud, such as Nodding Bur-marigold and Golden Dock

• These ponds support wetland plants around their edges but have almost no pondweeds in them. They tend to accumulate silt. You can read more about these issues and our management response

 

Ponds with an artificial water supply

  • Three ponds on Abbey Farm have an artificial water supply and so dry up less frequently than the spring-fed ponds:
    • A small pond at the eastern end of the pastures which is fed by water from the nearby Anglian Water plant
    • The pond in the bird hide car park which is fed by rainfall gathered on the rooves of nearby buildings. This was renovated in 2015 and is being left to colonise with plants naturally
    • The pond next to the bird hide (just to the south-west). This receives water that drains off Abbey Road. It partly acts as a silt trap to the other wetlands

Ponds that probably occur naturally:

  • There are a few pools on the pasture that fill with water when the ground around them becomes waterlogged by the rising water table. This creates two types of water feature:
    • Isolated pools that are not connected to other wetlands. These include a pond that forms in what is probably a pingo
    • Pools that are spring-fed and drain out into ponds or streams

Ponds made by digging into waterlogged ground:

  • The pond in the south-west corner of the public access area was made by digging a depression in a flat field immediately beside a stream. This pond always has water in because water percolates through the permeable ground into the pond from the stream
  • One disadvantage of this kind of pond is that making it involved digging up wetland grassland which itself was of wildlife conservation value