Ponds, Pools and Lochans

5.2 The three essential features of high quality wildlife ponds

Key principles of pond design are summarised in Box 4 and described in more detail in the remainder of this section.

There are three key factors which are critical to the creation of high quality wildlife ponds and all aspects of pond design can essentially be summarised under three headings:

  • unpolluted water
  • close proximity to other wetland or freshwater habitats10
  • a varied design.

If a new pond can combine any two of these factors, it is likely to develop a good wildlife community. If all three can be incorporated, then the communities that develop are likely to be outstanding.

Box 4. Key principles for pond creation

  • Locate new ponds to avoid or minimise exposure to water pollution. If possible create new ponds in areas where their catchments can be managed non-intensively - a good place to create a new pond is anywhere that unpolluted water can be guaranteed; a poor place might be (for example,) the corner of an arable field where the pond will drain nutrients and sediment from the field, and be exposed to biocide impacts. Box 10 provides special guidance on sustainable urban drainage system ponds which are designed to hold and treat contaminated surface water run-off.
  • Dig trial holes before the pond is created to determine where water levels will be and what the substrate is like.
  • Unless the pond is in a catchment with non-intensive landuse, avoid linking the pond to inflowing streams and ditches - these will create pollution problems in the long term by bringing in polluted water and sediment and may obstruct fish migration. Note that SEPA does not recommend the construction of on-line stream-fed ponds.
  • Where possible, create new ponds close to existing wetland areas (streams, fens, ditches etc.) but dont dig up existing wetlands (e.g. flushes, wet meadows, springs, temporary ponds) to make new ponds.
  • Design ponds with natural wetlands in mind: create pond mosaics and wetland complexes rather than single isolated waterbodies.
  • Focus on the edge habitats and maximise the extent of the drawdown zone (the area between the winter high water level and the summer low water level).
  • Most slopes at the edge of the pond should be very shallow; a gentle slope is 1 cm every 1m (i.e. 1:100). To maximise the extent of the drawdown zone dig down to just above the winter water level in dry ground (beyond the outer boundary of the pond) and then create very gently sloping drawdown area.
  • Create hummocks and hollows in the drawdown zone to maximise the hydrological diversity of this rich area.
  • To maximise species diversity, vary the main factors influencing community type at any pond site i.e. water depth, water permanence, pond area.
  • Make a particular effort to include (i) very shallow pools with a depth of no more than 5 cm (ii) temporary ponds as well as semi-permanent and permanent ponds.
  • Keep shallow and deep water pools separate - they can be as little as 1-2 metres apart but should not all be permanently connected (except, perhaps in winter high water conditions).
  • Vary the size of water bodies as much as possible - the smallest that you can easily create with a mechanical digger is about 0.5 metres diameter.
  • Islands are valuable for birds, and where the margins of the pond are shaded, heavily trampled or grazed, they can provide a different kind of habitat for invertebrates and wetland plants. However, keep most low and wet, i.e. mostly submerged in winter. High islands block views for birds and people and quickly become wooded.
  • Deep water (1 to 2 metres or more) is a specialised wildlife habitat most likely to be needed where fish or waterfowl are key objectives of the new pond. In the more remote areas of Scotland, where water quality is good, deep water bodies may also be valuable for some rare plant species.
  • Planting up is rarely necessary for ecological reasons, as colonisation is usually rapid (especially when other wetland habitats are within 1-2 km, or less). The new phase pond is also a particularly valuable habitat for specialist new pond plant and invertebrate species.
  • If planting-up of ponds is essential (e.g. in urban conservation schemes where it is important that something is seen to be happening very quickly), always use native species of local provenance.
  • Expect to take time - pond creation is often best considered as at least a two-phase process, with fine-tuning of the structure made 1 to 2 years after the first construction phase.
  • Ensure that some effort is allotted to pond management during critical early colonising stages, to ensure that one or two species of plant dont dominate the new site.

10 It is essential that in the process of locating new ponds close to existing freshwater habitats, no damage is done to those wetlands. Dont dig up bogs, pools, springs or flushes to make new ponds, unless this is part of the traditional management of a site.

ADLib logo Content provided by the Agricultural Document Library
© University of Hertfordshire, 2011