Essex Rivers Hub

Holland 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.

PRESSURES

SOLUTIONS

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.

Japanese Knotweed has been most recently recorded on this water body in 2008. 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.

 

This water body is classified as moderate for physical modification and is also considered heavily modified. The main reason being for flood protection.

Address the impact of the structures that are affecting fish passage and determine if any measures can be taken to reduce their impact. 

Saline incursion as well as other barriers such as weirs, locks, and sluices will be impacting on fish passage.

Address the impact of the structures that are affecting flow and determine if any measures can be taken to reduce their impact.

Flow is affected by a number of barriers, one of which being the dam boards installed near the coastal area.

Address the impact of the structures that are affecting flow and determine if any measures can be taken to reduce their impact.

The phosphate levels are classified as moderate within brook and dissolved oxygen levels are low and are classified as poor. The exact source of these issues is difficult to determine. These factors are having a negative impact on fish and invertebrate numbers. Ammonia has also been classified as moderate in the water body.

Addition surveys will be carried out on tributaries that join the brook and also checks will be made to ensure agreed individual sewage discharge levels are not being exceeded.

Sewage treatment works will also be investigated to ensure that they are not the cause of increased levels of ammonia and phosphate.

 

The phosphate levels are classified as moderate within brook and dissolved oxygen levels are low and are classified as poor. The exact source of these issues is difficult to determine. These factors are having a negative impact on fish and invertebrate numbers.

In order to determine the source of the phosphate levels further investigation is needed to determine the source. Further investigation is also needed to determine why dissolved oxygen levels are low.

Carp have been introduced in the brackish area where the river flows into the sea.

Engage local fishermen to ensure that there is no further stocking of the river.

Work to eradicate the carp on this stretch of river.

 

  

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