Our biodiversity programme is committed to protecting, restoring and enhancing the different forms of living organisms on our company sites, which act as links to the wider landscape. In addition to the importance of promoting the ecology and conservation of biodiversity, this also contributes towards meeting the National Environment and Rural Communities (NERC) Act objectives.

As part of our commitment to biodiversity, all our sites are subject to specific management plans, which vary in detail depending on the use of the site. These can range from basic ground maintenance and tree surveys; through to detailed ecological surveys and management plans. When works are planned for a site, a more in depth survey may be carried out so that appropriate action can be taken to avoid disturbance and, where possible, enhance species and habitats.

Below is a list of some of the surveys and monitoring that has been carried out:

Conservation management

  • Tree remediation work such as pollarding, coppicing or planting of new trees

  • Installation of bird and bat boxes

  • Reed bed management


Invasive species management

  • Japanese Knotweed removal

  • Himalayan Balsam removal

  • Quagga Mussel monitoring


Ecological surveys

  • Bird surveys

  • Butterfly surveys

  • Tree surveys

  • Reptile surveys

  • Water Vole surveys



Managing woodland to promote biodiversity

Our biodiversity programme aims to protect, restore and enhance different forms of wildlife on our sites across Kent and the Home Counties. All of our sites are subject to specific management plans, which range from basic, ground maintenance and tree surveys, to detailed ecological surveys and management plans.

In Kent, we are responsible for land and water at sites in the Dour area – Folkestone and Dover. Here most of the sites are either woodland or tenanted farmland. It was through the management of this woodland that we saw a need for more focus on biodiversity.

Sophie Mortimer, Project Manager of Biodiversity in the Southeast, explains: “There are many areas of woodland and countryside that we own. Until 2014 the core focus of our land management in these areas was around health and safety. We had employed a contractor to carry out tree inspections and remedial work on the trees and it was following one of their inspections they realised our woodland had amazing potential for wildlife and biodiversity.”

“Because it’s private, fenced off land, any wildlife within it has the potential to thrive – there are no walkers or dogs that could scare off wildlife or accidentally damage rare species of orchids. But also, because of this it had become overgrown. So, we brought a new holistic approach to managing our woodland from a biodiversity perspective.”

A focus on sites of scientific interest

We discovered that some of our sites either lay on the edge or are within the boundaries of Sites of Scientific Special Interest (SSSI) and other designated sites. They prioritise woodland within these areas and conduct surveys to find out what wildlife is present. These surveys form a large part of our biodiversity work with the community.

“We’re now working on numerous activities with local partners. Volunteers from our partnerships, such as White Cliffs Countryside Partnership (WCCP) and Up on the Downs, help manage our land, from conducting surveys to cutting back bushes around streams and coppicing. We will be doing species surveys with a focus on species that are identified as being the most threatened and requiring conservation action.”

Tree management to encourage wildlife

Alongside the wildlife surveys, we conduct tree surveys to see how trees could be managed sympathetically – for example, rather than felling a dangerous tree a decision is taken to pollard it to allow it to be a habitat for animals and plants.

This proactive tree management is helping to grow biodiversity across the company’s sites.

“At a site near Saltwood, we undertook a project that was very successful. It isn’t a public right of way, so there is great potential for this site to improve its biodiversity and promote species growth. There’s a horseshoe of trees around the site and some were at risk of falling onto our site with many having honey fungus. Some were left standing to act as dead wood which has supported a population of beetles.”

The work we are doing around biodiversity will continue over our five-year plan that runs from 2015 to 2020.




Birds and butterflies around our sites

Bird and butterfly surveys are carried out over a number of sites within our central region. Detailed surveys were undertaken in 2014 to establish how varied the biodiversity for the two species groups was and to suggest ways to enhance habitats to encourage greater biodiversity, especially for protected species.

The bird surveys were very encouraging with some unusual sightings including rare Goldeneye at Springwell Lake. These birds usually breed in the Highlands of Scotland, but recently, a pair bred at Springwell, which was one of only a handful of records of Goldeneye breeding in England.

The butterfly surveys also revealed encouraging results with 20 different species recorded over eight sites. These included declining species such as the Essex Skipper and the Small Copper (pictured left). This data has provided important ecological information about our sites going forward.




Tree inspections and surveys

There are a great variety of tree species on our sites. The three most common native species seen are:

  • English Oak - the most common tree species in the UK

  • Hornbeam - a common tree in southern England which is commonly pollarded and coppiced

  • Beech - due to its large stature, this tree plays an important role for rare flora including a variety of orchids, (source Woodland Trust)

We aim to manage and conserve trees across our company land holdings, together with the biodiversity they support. We promote additional planting of indigenous (native) species such as English Oak, Field Maple and Hazel. In 2015, we completed tree surveys that covered 69 of our landholdings, bringing the overall total to 124 surveys across all of the central communities we serve. We have chosen these particular sites having prioritised them according to biodiversity value, access provisions and recreational potential.

The surveys are conducted to promote proactive tree management on sites and removal of dead trees which were posing a safety risk on public footpaths and roads. The surveys have helped us to make recommendations for remediation work and biodiversity enhancement.

Recommendations to date include:

  • Coppicing (an English term for a traditional method of woodland management, young tree stems are repeatedly cut down to near ground level)

  • Pollarding (a process of cutting the top leaves and branches of trees to allow new growth on the top)

  • Felling (a process of cutting down a tree)

  • Removal of Ivy (to prevent endangering tree growth and swamping of other plants growing on or around trees)

  • Planting of native species (replacing trees which have been felled, to enhance biodiversity on our sites)

These are the before and after photos of some tree management in the Folkestone area. Although the Beech trees prior to management looked healthy to the untrained eye, inspections showed that they were top heavy, full of deadwood, had fungi on some higher branches and were being weighed down with Ivy. The pollarding of these trees means that they can regenerate and remain standing for decades to come.



Management of Beech trees in the Folkestone area to increase chances of regrowth



Brett Community

There are a great variety of native tree species on our sites in the Brett community which include:

  • English Oak (the most common tree species in the UK, Woodland Trust)

  • Alder (which plays an important role in the nitrogen cycle and is a valuable tree for many species, including many pollinating insects and birds, Woodland Trust)

  • Ash (a tree which is recovering from a disease - Ash Dieback, but has great wildlife value because of its long life-span, Woodland Trust)

Similar surveys were conducted to those in our central region to promote proactive tree management on our sites and removal of dead trees. The surveys have helped us to develop our recommendations for improvement work. These include coppicing, pollarding, felling, removal of Ivy and the planting of native species.



Brett Community

Invasive species surveys, monitoring and management

Invasive, non-native species are detrimental to our natural ecosystems, often out competing native species. Invasive species can be any kind of plants and animals, both aquatic and terrestrial that are not native to the UK.

We are currently undertaking invasive species monitoring, treatment and control at 15 different sites across all of our communities. Japanese Knotweed and Giant Hogweed are among the species identified and are subject to treatment and control management plans, preventing further spread and with the long term goal of full eradication.



Colne Community

The River Colne – eighteenth century to the present day

The River Colne played an important role to local communities and contributed significantly to local industries such as water mills since the eighteenth century. Mills were an important local industry at the end of the eighteenth century and there were thirteen in the Uxbridge area alone which were used by local farms.

“Mills on the River Colne are getting few and far between, and whereas a couple of thousand years ago there were scores of Colne Mills gaily going round and busily at work, there are, at present day, barely two dozen, and, alas! Even some of these are silent or even derelict”.

S. Springall (1907)

Other settlements within the area began to develop and grow, such as Colnbrook in the Nineteenth century as a river crossing and staging post. In general, the area prospered due to developments in transport, which in turn stimulated new industries and phases of house building. One such development was the construction of the Grand Union Canal. During the industrial revolution there was a great demand for improvements in transportation, especially between the industrialised Midlands and London. A canal route through Harrow was rejected in favour of the less popular plan to follow the Colne Valley. The canal stimulated local industries, such as copper works and sand and gravel extractions.

Colne Valley Park: A brief History (2003)


Colne Community

Wild Trout Trust river workshops


Wild Trout river workshop (courtesy of the Environment Agency, 2014).


In spring each year, workshops are run by the Wild Trout Trust which provides an excellent opportunity for us to work in partnership with the Environment Agency, Chiltern Chalk Streams Project and Hertfordshire County Council.



The aim of the workshops was to teach the use of tools and techniques for habitat improvement and management in order to enhance the rivers in our supply regions.


Our involvement

Workshops included installing a number of in-stream features to improve the habitat for fish and other wildlife. Mid-stream flow deflectors were installed to provide additional habitat for fish through the creation of scour pools and areas of slack water. Cover boards were secured to the riverbed to provide refuge areas for fish and river shelves were created by securing fallen trees to the bed and bank of the river. The shelves not only created additional habitat for wildlife, but also reduced the likelihood of flooding. All interest groups involved are now using these tools and techniques in order to protect the rivers and habitats in Hertfordshire.


Click here to find out more about the Wild Trout Trust river workshops



Colne Community

Tree management at Springwell Lake


A crane was needed to lift the felled poplars at Springwell Lake



We recently completed a large scale tree management project on our site Springwell Lake, near Rickmansworth. The project looked to enhance the health of the trees there and to allow them to continue to grow, which would help with their future management. The work also included liaising with the Environment Agency in order to preserve the various habitats around the work area, including birds and water voles.


Our involvement

This large scale project involved detailed planning and required the closure of the footpath around the lake. Over a four week period, four diseased hybrid poplar trees measuring 30 metres in height had to be safely felled. A 130 tonne crane then lifted them from the lake shore over the River Colne back stream and onto neighbouring land, where the wood was processed and removed from the site. Tree teams worked around the clock to pollard and dead wood a large number of trees at the site allowing the remaining trees to grow healthily. With regards to the various habitats in the area, the team used wood from the tree work to construct eco piles, which will provide a habitat for a range of species. The works also allowed more light into the river channel which will benefit aquatic plants, providing new habitats for aquatic species.

We are also are currently working in partnership with Herts and Middlesex Wildlife Trust (HMWT) on the Springwell Lake reed bed restoration project. Reed beds are among one of the most important habitats for breeding birds in the UK and support a number of species, including the nationally rare Bittern.



Dour Community

River Dour clean-up, Kent

Every year, a small team from our Dour Community join other enthusiastic volunteers to help clean up the River Dour in Dover and make sure that its banks and bed are clean and litter free.

Wearing waders and using litter pickers, the volunteers clean several sections of the river. They fish out branches and other debris that accumulate in rivers, and also unsightly rubbish left by fly tippers. The clean-ups, which are organised by White Cliffs Countryside Partnership (WCCP) and led by WCCP Dour Partnership Officer, take around 30 bags of rubbish from the river and its banks on the day.

WCCP staff said: “It’s essential to keep the river clean and the volunteers do a great job. If we didn’t have regular clean-ups then the water wouldn’t remain as clear as it is and an important chalk river habitat would be lost.

“We can now see brown trout breeding well in the Dour, showing that we have a healthy river that can support a wide range of wildlife. It’s thanks to the volunteers’ great efforts that the habitat’s restoration work can continue year on year.”

An Affinity Water volunteer said that he was surprised at the range of rubbish dumped in the river. He said: “It was everything from bicycles to bedsprings. If the river wasn’t regularly cleaned up then it would soon become unsightly and it’s a pity that people don’t take a moment to think before dumping their rubbish in it.

“When you work every day with water you realise the importance of our rivers and springs. The Dour is the only river in the area and we need to make sure it remains in good shape.”

Another volunteer added: “The Dour clean-up is part of our community engagement /volunteering activity that’s historically happened in the Southeast and which we’re looking to increase across the business. It’s ideal for us to take part. Not only is it local, but it gives us a good opportunity to meet our customers – many people stop and talk to the volunteers during the day to find out what’s happening and there’s great support and appreciation for the cleaning.”

Affinity Water has worked with WCCP in the Southeast for more than ten years, and historically the tasks have been either on Affinity Water land (managing biodiversity) or in key areas which benefit the community. The area that WCCP cover mirrors our supply area in the Southeast, and they have a programme of volunteer activities throughout the year which anyone is welcome to attend.

To find out more about WCCP, visit their website


Lee Community

Keeping our rivers flowing, Hertfordshire

On 10 July 2014, six volunteers from four different directorates participated in a “Himalayan Balsam Pulling Day” that was hosted by the living rivers officer from Herts and Middlesex Wildlife Trust.

The event to protect chalk stream biodiversity took place along the River Beane, a precious chalk steam in our supply area. An interesting fact is that there are only around 210 chalk streams in the world. That makes them rarer than Giant Pandas and a large number of them are found in Southeast England.

All in all the day was a great success and our staff were able to work alongside: local charity members, HMWT, local interest group the River Beane Restoration Association and community volunteers. This collaborative approach from all involved enables everyone to make a contribution towards river restoration, through invasive non-native species control. All participants enjoyed being outdoors and thought it was a good physical activity. Furthermore everyone involved also had a chance to learn from experts who knew about the history of the river as well as about invasive species identification and control.

Lee Community

Otter Holts, Hertfordshire

When Herts and Middlesex Wildlife Trust (HMWT) contacted us for a donation of drainage pipe to build an artificial Otter holt, we were more than happy to help out. Within a couple of months a team of Trust staff and volunteers had constructed the new home in the Lee Valley using some surplus polyethylene pipe and some recycling boxes donated by Stevenage Borough Council.

The HMWT Conservation Manager said: “Otters are still very rare animals in Hertfordshire, there are only a handful left, so it’s really important we take action to help the Otters that are left, enabling them to thrive. Providing secure places for them to live and breed is important in their survival. Otters only live for three to four years in the wild, so unless they’re successful breeding, they could become extinct.”

There are many different styles of Otter holt, but the pipe and chamber holt that has been built using our pipe is the best kind – it is long lasting and extremely secure.

Along with the holt, the Trust has created fish refuges in lakes by felling some trees, so the crowns of the trees rest below the water. “The submerged tangle of branches and twigs provide a safe place for fish to survive during the winter months and breed,” continued the HMWT conservation manager. “The Otters then benefit from the abundance of fish.”

The holt was constructed in a known favourite quiet area for Otters, a space that’s unlikely to be disturbed by people or dogs. Over the next year, the Herts and Middlesex Wildlife Trust will monitor the holt for evidence of usage.


Lee Community

Water Vole surveys

On 9 April 2015, a number of scientists from the Water Resources team attended a Water Vole survey training day. This was hosted by Herts and Middlesex Wildlife Trust at Denham Country Park, Buckinghamshire.

The training enabled team members to gain knowledge and experience of Water Vole surveying so we can deliver in-house surveys as part of our biodiversity programme. This has led to one of our Environmental Projects Officers carrying out an investigation into the population of water voles on the River Mimram.

There is currently an isolated population of approximately four Water Voles that are permanent residents on a stretch of the River Mimram in the Lee Community. They are often seen by local home owners as they have unusually built a series of burrows utilising gaps in the bridges of their back gardens. Evidence suggests that there are also isolated Water Vole populations on other parts of the River Mimram. It is hoped that habitat improvements carried out in the area will increase Water Vole populations on other parts of the river.



Pinn Community

Barn Owl and Kestrel monitoring, Hertfordshire

We work in close partnership with the Wildlife Conservation Partnership (WCP) which monitors company land for the presence of Barn Owls, Kestrels, Tawny Owls and Little Owls. We now have 70 nest boxes on 42 land holdings across our Colne, Lee, Misbourne and Pinn Communities. Each nest box is inspected annually and the bird presence recorded.

Barn Owls use nesting sites ranging from tree cavities to rock ledges, but it is estimated that up to 80 per cent of the population now live in man-made boxes. In 2015, Barn Owls were found in seven boxes. Eight boxes were confirmed as being used by Kestrels. In addition, Jackdaw and Stock Dove were also found nesting. This means that 41% of all boxes were occupied, with 24% by target species.

Although both Barn Owls and Kestrels are widely distributed across the UK, in recent decades their numbers have declined dramatically, largely because of the intensification of agriculture. By providing additional nesting sites on our sites, we are helping to prevent a further decline in species numbers.



Barn Owls (left) and young Kestrels at our site (Photos courtesy of Colin Shawyer, Wildlife Conservation Partnership)



Wey Community

Fish friendly screen installation at river intakes

Between 2013 to 2015, fish screens were installed at our river intakes on the Thames in order to protect fish and eel populations. This was required under our duty to meet the Eels Regulation (2009).

We continue to lead by example as one of the first companies in the country to install and operate these fish friendly screens. We have shared our experience with other water companies and the Environment Agency (EA).