Essex Rivers Hub

Layer Brook Pressures

The table below shows the current pressures that this waterbody faces and the solutions that could be put in place to solve these problems. You can learn more about some of these pressures and solutions on the Environment Agency Catchment Data Explorer or you can contact us to find out more.



New Zealand Pigmy Weed has been most recently recorded on this water body in 2009. This plant forms dense mats in waterways, increasing the likelihood of flooding and also out-competing native species.

This plant can be mechanically removed, but this would only be a short term solution. Chemical eradication is possible and if done correctly can be very effective. After eradication it is important to monitor sites to ensure that it does not take hold again.


Japanese Knotweed has been most recently recorded on this water body in 2013. This plant not only shades out native plants, but also causes serious damage to buildings.

Japanese Knotweed can be removed by spraying or injecting its roots with pesticides, this takes time to kill the plant, but it is effective. Just digging up this plant is, unfortunately, not enough.


American Mink have been most recently recorded on this water body in 2007 and 2009. American Mink cause a wide range of problems on a river, including playing a large part in the local extinction of many natural species such as water voles and kingfishers.

 In order to eradicate mink, they must be trapped and dispatched. Trapping must be done catchment wide as mink can travel large distances. It is important that there are enough people involved in a trapping project to ensure that the traps can be checked regularly. Monitoring mink, water vole and otter presence on your river can also help us when planning eradication programmes.


Signal Crayfish have been most recently recorded on this water body since 2000 to 2008 . Signal Crayfish cause changes to the natural bankside habitat and also out-compete our native crayfish. They are fierce predators and can completely change fish and invertebrate communities so that they are no longer in their natural state.

There is currently no known solution to the invasion of Signal Crayfish, regular monitoring is needed to ensure a strategic approach when a solution has been identified.


Abberton Reservoir is an unnatural impoundment of water which affects the ecology of this water body.

There is no further action that should be taken here as the reservoir is a required modification that has social and economic benefits.

Flow is impacted at this site because of surface water abstraction from Abberton Reservoir. The low flow in this water body is also contributing to failing fish populations. Low flows are causing increased sedimentation.

Ensure that the amount of water taken is appropriately managed to maintain aquatic plant and animal communities

This water body is classed as bad for both phosphate and dissolved oxygen, with ammonia being classified as poor. There is a sewage treatment works that discharges within this water body which could be a likely source of ammonia and phosphates, contributing to the decrease in dissolved oxygen. Other sources could be from local industry.

Investigate outfalls from local industry and sewage treatment works to determine the level of inputs.

This water body is classed as bad for both phosphate and dissolved oxygen, with ammonia being classified as poor. Diffuse agricultural pollution is contributing to this although specific areas have not been identified.

Determine which areas are contributing most to increased phosphate levels.

Work with landowners to introduce pollution prevention schemes.


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