South East Rivers Trust (& the Wandle Trust)

The Acacia Hall/Central Park Restoration Project: Returning the Darent to Central Dartford

“Chalk rivers should be protected or restored to a quality which sustains the high conservation value of their wildlife, healthy water supplies, recreation opportunities and their place in the character and cultural history of the landscape.”

The State of England’s Chalk Rivers” World Wildlife Fund UK, 2014

A river runs through it

Anyone who walks through central Dartford’s bustling high street only has to turn right past the Museum to find Central Park – the town’s fantastic 26-acre green space with Acacia Hall just next door. The town and the park sit on the valley floor of the River Darent, which flows through the park on its way to the River Thames, approximately 2 miles downstream.

The River Darent is a chalk river – a rare and beautiful but heavily impacted freshwater habitat. Good quality, relatively unaltered chalk streams are characterised by cool, crystal clear, high-quality water filtered by underground chalk aquifers, with clean gravel beds and pockets of lush aquatic plants that provide important habitats for native fish (such as brown trout) and invertebrates.

River Darent at Eynesford

The Darent is one of only 210 chalk streams in the world; 160 of these are in England.

The Darent is an important chalk river, a fundamental part of the regional landscape. Sadly the Darent today suffers from a legacy of modification by human activity. Former water mills, over-abstraction, polluted outfalls, flood risk prevention measures and weirs fragment this precious chalk stream habitat. These change the river from a continuous, free-running ecosystem into semi-isolated or “impounded” bodies of standing or slowly moving water. This physical impact completely alters chalk stream ecology, impeding the movement of many aquatic species and affecting water quality. Over-abstraction has had a significant impact on the Darent, and silt originates from urbanisation and agricultural practices.  Bit by bit, as a fragmented river gradually silts up and loses its crystalline beauty, it runs the risk of becoming a forgotten backwater, a silty supermarket trolley repository.

Some typical chalk stream species: Otter, Kingfisher, Brown Trout and Damselfly (Sally Ann Symis)

The part of the Darent that runs through Central Park has been subject to heavy modification in the past.  It has been widened to increase the capacity of the channel, and the weir prevents fish migration and impounds the upstream section of the river. Together, these result in siltation and degradation of the river habitat. The river’s flow in this channel has been impeded, and the flood relief channel has become the main watercourse.

The Darent in Central Park – May 2019

Now, we’re working with Dartford Borough Council and the Environment Agency on the Acacia Hall/Central Park Restoration Project. The project will bring the Darent back into the heart of Central Park/Acacia Hall by removing the Acacia Hall weir and using flood risk neutral, nature-based methods and materials to reintroduce chalk stream river habitats and function. The Central Park/ Acacia Hall section of the Darent will flow again, allowing the public to spend time by a natural chalk stream with improved water quality and benefits to wildlife such as otter, brown trout, European eel and invertebrates.

Restoring the Darent in Central Park and Acacia Hall: how will it be done?

Our river restoration project will reintroduce natural features to the river, to create the type of variation in channel width and depth found in less disturbed river systems. These improvements will “kick-start” more natural, variable flow patterns – creating a greater variety of habitats that attract and support wildlife. Greater habitat diversity supports more resilient wildlife communities.

Examples of nature-based methods used in another South East Rivers Trust river restoration project on the Beverley Brook (Richmond Park). These methods will be used in the Darent in Central Park and Acacia Hall (Source: South East Rivers Trust).

The natural features will be made from materials that naturally occur in river ecosystems, such as Large Woody Material, gravel and silt.  Dartford Borough Council Parks Department has worked with the South East Rivers Trust and the Environment Agency to select trees in the Central Park area that will be felled to be used in the restoration project.

Many of the selected trees – which are being assessed to avoid disturbing any bat roosts – are damaged, hazardous to the public or are self-seeded sycamore. Sycamore is a fast-growing non-native tree species that out-competes many native tree and shrub species, and blocks out the sunlight to the river.  A heavily shaded stretch of a river cannot sustain stands of aquatic plants or clear waters that support more diverse wildlife communities.

By opening up areas at selected sites in Central Park and Acacia Hall, the restoration project will create a mosaic of sunny and shaded spots for river habitats.

When will it be done?

The restoration work will start this summer as part of the Acacia Hall regeneration project. The creation of more natural banks, a more varied meandering river and improved marginal habitats throughout Central Park will allow everyone who visits it to experience more wildlife such as fish, birds and dragonflies.

To enable the work to take place safely in the channel, the water level will be lowered and flow will be diverted down the Flood Relief Channel to the east of Central Park, leaving a dry western channel to work in. This means that wildlife will not be harmed whilst the work takes place. All fish will be safely removed before the works commence. The restoration site will be fenced off during the works for public safety.

A vision for the Darent at Acacia Hall/Central Park

The vision driving the restoration of this section of the River Darent is to enhance the river channel through Dartford’s most valued urban green space, providing a focal point of natural aesthetics, amenity and wildlife habitats. The project will reconnect park users with the river, with possibilities for nature conservation, environmental volunteering and education opportunities. The new naturalised river channel will become a community resource, bringing biodiversity value in the heart of urban Dartford.  The local community will benefit from these river improvements that will create an attractive environment where people want to be.

Have any Question or Comment?

19 comments on “The Acacia Hall/Central Park Restoration Project: Returning the Darent to Central Dartford

Jr hartley

Dartford river if you put fish that smells trouble its could cause unwanted fisher men kids or pouchers there as a fisherman my self you see polish people fishing round wicks trying to take the last remaining carp from the river already and noone doing nothing about it let. Now your thinking puting new fish in the river mad


Hello, I run a group called river darent and cray angling on Facebook. Up to 400 members. When will this work take place and can we get involved? Can we come down and take pictures? We have two admins, myself and Dan guyton. We organise regular river cleans and have many members that fish this section regularly. Are the fish being put into the other section?
We would like to get involved if possible as we both have a vast knowledge of local wildlife and the fish that swim in our little river.
Richard clark.

Paul Cooper

I am personally very pleased to hear that the river may return to its formr glory. I’m omd enough to remember the last time changes were made post the 1968, creating the core of what we have today – a silty, clogged up mess.

I live very close to this stretch of the river. Could you please assure me categorically that this work will not increase local flood risk?
Thank you


Hi there, I’d be very interested in getting involved with this. Could you point me in the right direction?

Conrad Broadley

What happens to the Eastern channel after you’ve lowered the water level, currently the Eastern Channel is in fact a chalk stream, will you destroy that habitat to create another one adjacent. I thought we’d knocked this into touch in 2007. Regards Conrad


Hello Jack, and thanks for your interest. We will be carrying out volunteer planting days towards the end of the project. Best thing is to join our mailing list which we send all our volunteering opportunities too:


Hi Paul. We hope that you and everyone else that lives close by will enjoy the Darent once again! The restoration designs have been modelled several times under different flow scenarios and are flood neutral. In other words, based on model output, the proposed restoration measures do not add to any existing flood risk in the area.


Hi Richard. Thanks for getting in contact with us. The work will take place this summer and you are welcome to take pictures during and after, as our work “settles in” post-construction. Works will take place in a dry western channel, so all the fish will be removed. This can only be carried out by people licensed to carry out such activities. We would be very interested in finding out what you know about the Darent. We will have a stall at the Dartford Festival this July. Please come and visit us!


Hi Conrad, Sam (our Project Manager) will be getting in touch with you directly to discuss this and address your concerns. Thanks!


Thanks for your interest in the project. Both Dartford Borough Council and the South East Rivers Trust will use a specialised company to remove fish from the stretch of river that is due to be restored. We will not be restocking the river, because local fish populations will naturally recolonise the restored stretch of the river.


So where will the fish you take from OUR river be relocated to if you are not going to return them ???
Why not just stock them upstream of the works thus enabling them to naturally return to the area once the work is completed????


People are very bad about littering in the park. Will not a low-flow river in the intensively used park become filled with litter, bottles etc and not be self cleansing? Will someone undertake to regularly clean it up?


Hi Keith, the low flow channel just means that the river is narrowed to ensure that during low flows, there is sufficient water for fish and wildlife to survive. Rather than low flows spread across a wide channel, meaning the depth is 2 cm, a low flow channel would pinch the channel making the same amount of water deeper. In theory, this will actually help move litter on and be more self-cleansing. However, we are planning events to litter pick and help reduce this problem as well.

Kevin Hodgson

Are there any other plans for the river Darent further up stream. The river running through Darenth has become clogged with reeds, silt and overgrown trees, which is causing narrowing of the river to the point that by 2021 the river will not be visible. This will result in a trickle that will eventually clog up with silt , making all the work in the park worthless.

Malcolm Pearce

We watched the progress of the restoration with great interest up to the time of the Covid lockdown. We returned to the park this week only to be greatly disappointed at the lack of progress. In fact it seems as though progress has been reversed with the undergrowth now starting to block the channel again. Is this the result of the lockdown or has the project hit problems?

Jess Mead

Thank you for your message. Yes, the Darent and Cray Catchment Partnership, which is co-hosted by us (South East Rivers Trust) and North West Kent Countryside Partnership, are working on several restoration projects throughout the catchment. The Partnership has a number of aims inc. to improve water quality, to restore the river to a more naturally functioning watercourse and to help local communities enjoy, engage with and protect the river. The river Darent has been modified for water milling, the water mills no longer function and therefore no longer provide society with this power source benefit derived from the water course. However the milling infrastructure remains which creates barriers to fish migration and degraded upstream impoundments. The situation you describe in Darenth may have been caused by the modifications made to the river, we visited this area last year at the request of the Darent River Preservation Society and a local resident, and I think I know the site you refer to. The old mill site splits the flow and the section between the split is over wide, due to the engineered channel and milling legacy. The river is trying to narrow itself in response. Rivers are natural dynamic systems and nature will, eventually, return it to a natural state, however river restoration aims to accelerate this process. There is potential for a project here, but it isn’t developed as yet. If you are a land owner or local resident who would like to get involved and help facilitate this, please drop us an email at info@southeastriverstrust and we can discuss this with you.

Jess Mead

Hi Malcolm, Thanks for your enquiry. The Central Park restoration, like many project “on the ground” has been affected by the pandemic, lockdown and furlough. We have had to push back some activities – such as planting – that were due to take place in Spring because of this, but we are carrying out regular maintenance surveys to make sure everything is okay. We are in constant contact with DBC and EA about this project and will keep you posted about any developments.

[…] Over the past two years, SERT has collaborated with project partners (Dartford Borough Council, the Environment Agency and North Kent Countryside Partnership) and CBEC to draw up the most suitable flood-neutral restoration design for the site. You can read the our Introduction to this work here. […]

[…] To read up on some of the background behind this project, why not check out our previous blog. […]

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