Drought and ponds

Drought and ponds

Wildlife pond by Anna Williams

Beth shares some tips for supporting wildlife and ponds during a drought...

For two summers in a row, drought has been declared in Worcestershire. While the Environment Agency explains that droughts are natural events that cannot be defined, as every drought is different, they are normally characterised by a shortage of rainfall. As climate change progresses, we are likely to see more of these extreme weather events, including extremely low rainfall, or extreme rainfall. 

Ponds can help to provide resilience in the landscape for either extreme by storing water and releasing it slowly into the environment, providing wetland habitats for species that need it and relief for heat-stressed flora and fauna. 

A male broad-bodied chaser, with a wide blue abdomen, resting on a stem

Broad-bodied chaser © Vaughn Matthews

During the last two summers we have been contacted about multiple ponds drying out and, understandably, people are concerned about the wildlife that relies on these ponds. This is understandable but it may not be as big an ecological disaster as first thought. Many ponds can be classed as ephemeral, or seasonal, and are prone to drying out. These types of ponds still hold a high ecological value as some invertebrates have adapted their life cycles to suit this sort of temporary wetland. For example, nymphs of broad-bodied chasers, which are one of the first dragonflies to colonise garden ponds, can tolerate some drying out of ponds as long as there’s damp at the bottom.

Below are some general tips to help you support wildlife and ponds during a drought: 

  • Amphibians and invertebrates can hunker down in damp silt or soil at the bottom of the pond or in other damp terrestrial habitats, so even if you’re tempted to use this opportunity of dry weather to desilt or remove vegetation, please leave it in place for wildlife to shelter in.
  • Pond maintenance should take place October – January, as this will avoid the time of year amphibians use ponds for breeding. However, some invertebrates, such as dragonflies, have a two-year life cycle, which mainly takes place within a pond or its vegetation. In this case, if you are removing vegetation, please leave it with the root side closest to the edge of the pond, so any larvae yet to emerge can find the pond safely.
  • It is likely with the drought continuing that ground water levels will still be below average in October, so there’s a good chance the pond will still be dry or have low levels to enable easier maintenance in the autumn.
  • Even if overgrown, please don’t remove any vegetation as it will help keep moisture in the pond and provide shading.
  • Please do not move any amphibians to other ponds where there might be more water. It may spread diseases, and some amphibians are very site loyal anyway, so will likely try to return, which could also expose them to harm from hot weather, predation or cars.
  • If you fear a garden pond is going to go completely dry, without any damp silt in the bottom, then it should ideally be topped with rainwater from a water butt.
  • Understandably, during a drought, there is a good chance you may run out of water in your water butts and be tempted to use tap water, however, tap water can be high in chemicals and nutrients that can be bad for wildlife. If you feel compelled to top up a pond, then aim to leave water in a container for 48 hours before adding it to allow some of the chemicals to evaporate. Do not aim to fill the pond, as just maintaining a level of dampness will be good enough for most species. A good alternative would be to leave a shallow dish or tray of water out for wildlife to use instead.
  • You should always check your water companies’ guidance for temporary use bans (often called a hosepipe ban) or non-essential use bans, as they may ask you to refrain from topping up ponds with tap water during this time. Although this may seem worrying it, during a drought it’s important to remember that water companies and statutory bodies will be working hard to maintain a healthy flow in rivers or ground water levels. The more we take from a tap, the more water companies will need to extract water from the natural environment, which can also be detrimental to wildlife. 
A pair of hands putting stones into a newly created pond

Creating a pond by Penny Dixie

It’s understandable that people may feel worried for the wildlife that relies on ponds but a healthy wetland is a resilient one, so once we exit the drought, there is a good chance that they will recover. This makes our work on resilient wetlands even more essential! 

There are also ways you can prepare for future weather extremes, such as installing more water butts where practical to do so. These will collect water when it rains and stop it going into the wastewater system, enabling you to reduce your need to rely on tap water during hot weather. Topping up a pond with rainwater is the best option for wildlife. Good pond maintenance will make it more resilient to drought. Having an overgrown pond, a pond with too much sediment in the bottom or a pond liner with a leak can lead to the pond drying out more quickly.