Rewilding Queensmere

Supported by the Mayor of London, in partnership with London Wildlife Trust

Wimbledon and Putney Commons Conservators are embarking on a major habitat restoration project to transform Queensmere Pond from a Victorian concrete banked bathing pond into a thriving space for nature. 

This project will increase biodiversity by creating marginal planting with 1200m2 of reedbed habitat. The vision is to see the pond alive with wildfowl, frogs, newts, dragonflies and an abundance of plants.

 

About Queensmere Pond

Queensmere pond (or Queen’s Mere) was built to commemorate Queen Victoria’s Golden Jubilee in 1887 and was once considered the jewel in the crown. It became known as a bathing and boating pond until a few decades ago. Nowadays it provides a popular walking destination for people who come to enjoy watching the birdlife.

Despite being located within the green and natural landscape of the Commons, this man-made pond with its concrete banks provides little in the way of ecological value. Thanks to funding from the Rewild London Fund, we’re working to rewild the pond so that it can become a better place for wildlife.

 

Why did we carry out surveys first?

Before you make changes to a pond with the aim of improving its ecological condition, it is important to understand what factors are affecting it and have full information about the pond’s existing wildlife.

Its clear from looking at the pond that it suffers from silt build up, but before we proceed with desilting we need to ask whether this process will provide benefits to wildlife or if there are any communities in the pond that it could negatively affect. In addition, removing silt from a pond is expensive due to the equipment needed so we wanted to make sure it is the right course of action.

Other questions included what would we do with the silt, how would we prevent it from reach the pond in future, how would we encourage marginal planting and how could we improve water quality?

 

What did we learn from the surveys?

The condition of a pond can be shaped by various factors. Nutrients in the water can become imbalanced due to the wildlife that uses it, it can become shaded by surrounded trees, silt can build up which can make the water murky and how visitors and dogs access the area can change what vegetation grows. These factors can reduce the ecological value of a pond, especially in terms of diversity of species.

 

What wildlife uses the pond?

A number of surveys have been carried out to understand what wildlife currently uses the ponds. This includes carrying out eDNA sampling for Great Crested Newts, a fish survey, and checking biological records with GiGL. The surveys confirmed that there are no protected species within the water, such as Great Crested Newts or eels. The fish survey confirmed that pike, perch and tench are present.

Queensmere is popular with waterfowl. These include Canadian Geese (Branta canadensis), Greylag Geese (Anser anser) and a smaller population of Egyptian Geese (Alopochen aegyptiaca). Other bird species observed within the pond area boundary include the Black headed gull (Chroicocephalus ridibundus), European herring hull (Larus argentatus), Lesser black-backed Gull (Larus fuscous), Mallard (Anas platyhyhchos), Coot (Felice atra), Mute Swan (Cygnus olor), Moorhen (Gallinula chloropus), Tufted Duck (Aythya fuligula), Cormorant (Phalacrocorax carbo) and Grey Heron (Ardea cinerea). 

 

Plants

 A good sign of a healthy pond is an abundance of diverse planting. Plants attract wildlife such as amphibians and invertebrates as well as providing refuge for waterfowl.

There is no marginal planting around the banks of Queensmere, except for duckweed, blanket weed and water lilies. This is due to its concrete banks and the shading of the surrounding trees. 

The ground on the adjacent banks is bare. This is due to surface water run-off and also erosion from visitor, dog and waterfowl use. This erosion prevents vegetation from taking hold of the bank and the lack of vegetation increases the extent to which surface water runoff erodes the bank.

Recommendation - The concrete banks will be reprofiled by installing coir rolls which will be planted with native aquatic plants. A reedbed will be created to provide new habitat as well as helping to filter the water.

 

Sediment

The amount of silt build up is visible at the inlet (the narrower end of the pond). Silt has built up over many years due to debris and leaf litter from the surrounding trees, but mostly due to the location of the pond being down slope. As water travels down the streams and slopes, the sediment travels with it. This is leading to high organic matter and impacting the water quality.

Recommendation - Desilting the lake will improve the overall health of the lake through removing the component which is driving and exacerbating the poor water quality factors seen here. The silt that is removed during the desilting process can be reused to relandscape the eroded banks which will be seeded to provide a vegetative buffer against slope run-off.

By slowing the flow of water in the connecting streams, by creating leaky dams and leading it to the reedbed, the sediment will be caught before reaching the pond, settling between the plants. Not only is the sediment trapped, but a reedbed helps as the pollutants and excess nutrients are pulled out of the water here, too.

 

Tree management

The pond is over 50% canopy shaded which limits marginal plants from establishing.

Recommendation - The alders around the waters edge will be coppiced to allow more sunlight in to help oxygenate the ponds and help the reedbed grow, to reduce the amount of leaf litter falling into the water helping to prevent the ponds silting up in the future.

 

Visitor access and experience

Whilst the plants grow and establish these areas will need to be temporarily fenced off so that the plants do not get trampled and the seeded areas eroded. Access to the waters edge will be provided via unplanted sections and a viewing deck. The deck will be a beautiful spot to see wildlife and admire the views across the pond. Signage will be installed about the wildlife to spot.

 

Rewilding Queensmere - The Plan

With the funding from the Rewild London Fund, this means we can now deliver some of the recommendations. Plans are being made for work to begin in October 2024 after the summer's bird nesting season.

Desilting - around 2,500 cubic metres of silt will be dredged from the pond and then reused to relandscape the banks. 

Marginal planting - coir rolls planted with native wetland plants will be used to create natural banks and to provide marginal planting.

New reedbed habitat - 1200sqm of new reedbed habitat will be created at the inlet of the pond (the narrow section where water enters the pond from the connecting streams. 

Reedbeds help filter the water and catch silt and pollutants before they enter the pond. 

Silt control - the remaining silt will be used to create silt trap lagoons to trap the silt before it enters the pond. 

Access - viewing deck constructed to provide visitors access to the waters edge