What's new in Epping Forest

Guidance is being issued to the public after DEFRA confirmed cases of avian flu in Epping Forest.

Visitors to the site, which is managed as a registered charity by the City Corporation, are being asked to follow Government guidance:

• Keep to footpaths
• Keep dogs on leads
• Do not feed wild waterfowl
• Do not pick up or touch dead or sick wild birds
• Do not touch wild bird feathers or surfaces contaminated with wild bird droppings
• If you keep poultry or other birds, wash your hands, and clean and disinfect your footwear before tending to your birds
• Report dead wild waterfowl (swans, geese, or ducks) or other dead wild birds, such as gulls or birds of prey to the Epping Forest team on 020 8532 1010. They will arrange safe collection

Chairman of the City of London Corporation’s Epping Forest and Commons Committee, Ben Murphy, said:

“The UK Health Security Agency has said that avian influenza is primarily a disease of birds and the risk to the general public’s health is very low.

“Therefore the UK is facing its largest ever outbreak of bird flu and it is absolutely vital that we work together to help stop the spread.”

Epping Forest is London and Essex’s largest green space and is known as “the green lungs of London”.

The Forest is of national and international conservation importance, containing two registered historic parks, seven listed buildings, and three scheduled ancient monuments.

More than two thirds of Epping Forest is designated as a Site of Special Scientific Interest and a Special Area of Conservation. 

Visit GOV.UK for more information on avian flu.

Wanstead Park’s 300-year old cascade lake system, which was originally constructed circa 1715, has had a long history of low water levels.

The City of London Corporation purchased what remained of Wanstead Park in 1880 to prevent further loss of the parkland landscape to development. At its greatest extent (circa 1800) there were nine lakes in the lake cascade system. Of these The Great Lake, The Reservoir, The Lake Pond, and the Square Pond have all ceased to exist. There have been significant changes to the size of Heronry Pond and the interaction of the Ornamental Water and the River Roding. At one time the River Roding was linked to the Ornamental Waters and flowed through the lake.

Today five lakes remain. They run in a semi-circle in an anticlockwise direction. The Basin, which is the head of the cascade in the ownership of Wanstead Golf Club, the next four lakes running down the cascade are Shoulder of Mutton, Heronry, Perch Pond and the Ornamental Waters
(which is in the flood plain of the River Roding) are all under the City of London Corporation ownership.

The areas surrounding the Park have changed massively over the centuries. The park catchment for water run off to feed the lake cascade system at one time extended as far Eagle Pond. This water ran through the ‘River Holt’, a ditch created by Adam Holt the gardener to the Earl Tylney.

To the east and south of the park, the Lake House Estate and Albersbrook Estate where also once part of the originally parkland. These developments reduced the catchment area further.

Works were undertaken in the early 1906/07s to reline the Heronry Pond and is much the same as we see it today. In the second world war the northern edge of the Heronry Pond was hit by several high explosive bombs. Then, in 1944, a V1 flying bomb landed right in the middle, creating a large crater. Repairs were carried out but were not successful in stemming leakage. Further attempts at repair were made in the 1950s but unfortunately we still have issues with leaks.

Originally, the Lord of the Manor was able to dam the River Roding to direct water into the Ornamental Water. Later, the City of London Corporation, while not able to dam the river, was able to pump from the Roding. This practice happened until 2000. In 2001 a borehole was sunk to pump water from the aquifer into Heronry and Perch Ponds – which continues to this day.

We have a license from the Environment Agency that limits the amount of water we can extract – so that the aquifer can recharge with water. We currently pump to the maximum capacity of the pump which is 16 hours a day into the Heronry and Perch Ponds which in turn overflow in to the Ornamental Water, providing its only means of being topped up.

Detailed hydrological assessments undertaken by specialist engineers have shown that there is insufficient natural water to keep the lakes filled. Water losses from leakage and evaporation outstrip the amount of water entering the lakes and if water was not pumped into the lakes they would ultimately be much reduced in size, if not lost.

Interventions to increase water levels

The City of London have taken a number of steps to address the low water including commissioning a detailed Parkland Plan and Hydrological Survey. In 2019, a 330m ditch starting near Blake Hall Road was cleared to enable water to move more freely helping it reach the lake system rather than be absorbed into the land.

We are currently working on these areas to increase water into the lakes including:

• Designs and specifications are currently being drawn up to install land drainage to capture water to feed into the Ornamental Water.
• Designs to replace the pumping infrastructure at the River Roding are being worked up with a view to reinstating winter pumping from the Roding. This would be subject to a license agreement being granted by the Environment Agency.
• We have been awarded a development grant from the Mayor of London’s Green Resilient Spaces fund for a feasibility study looking at possible Sustainable Urban Drainage Scheme (SuDs) ad part of developing wetland habitats at the park and to try to get more water into the lake system.

In 2018, the Environment Agency confirmed the water bodies as “High Risk”. To ensure that the dams operate safely during major flood events, consulting engineers were commissioned and, following a 1-year study in 2020 recommended approximately £1M of improvements to the lake dams including:

• Regrade some of the earth dams to ensure they are at a consistent level – in the event of water flowing over them to ensure water overtop the entire length of the dam, minimising earth erosion due to strong flows.
• Installing concrete edging beams on some of the earth dams.
• Regrading of the downstream face of the Heronry dam.
• Maintaining a short grass surface to the dams to minimise earth erosion in the event of overtopping.

A further study was recommended to assess the flood interaction of the River Roding and Ornamental Waters. This study was completed in November 2021. It recommends minor works to build up levels either side of the two earth dam embankments on Ornamental Water. It also states that if there is a prolonged period of draught longer than 18 months that this could cause issues with the two earth dams – due to drying out. Funding for this essential safety work has been secured and works will be implemented over the next 2-3 years

How we manage water levels

The water levels in the lakes are maintained through pumping water from a borehole. The pump is operating at maximum capacity and works for two periods of eight hours with an eight hour aquifer recharge period.

Borehole water can be pumped directly into the heronry pond where this can be seen exiting a pipe near to the tea hut. Borehole water is also pumped into the Perch pond where it enters the pond below the surface so cannot be seen.

Once the Perch pond is full then the water overflows and goes into the Ornamental Water via a small stream through the Dell.

In the winter months we seek to get as much water as we can into the Ornamental Waters, however, in the summer months to keep water levels in the Heronry pond sufficiently high we need to pump more frequently into the Heronry pond. This means that water levels in the Ornamental water do get lower and the stream through the Dell can stop flowing for a while.

Water levels and wildlife

Staff and volunteers monitor the wildlife of the lakes. However, if you have any concern please contact the Epping Forest Team.

If you see animals in distress, you can find out what to do on the RSPCA's website.