Essex Rivers Hub

This waterbody contains multiple small rivers and brooks that lead in to the Stour Estuary. The four main water bodies are named after the four main bodies of water, although do contain other named bodies of water: Stutton Brook, Holbrook, Wrabness Brook and Ramsey River.

The Water Framework Directive (WFD) status for these water bodies is currently at moderate status for Wrabness and the Ramsey River, and at poor status for Stutton Brook and Holbrook.

Although classed as moderate, there is a complete lack of information on Wrabness, as currently only morphology and hydrology have been investigated. Both have been classed as moderate; with no biological data however, there is no way for the impact of the failing hydrology and morphology to be assessed. The main next steps for this water body are to do further biological and water quality investigations so that a true classification can be reached. This is not the case for the other three waterbodies within this catchment, as all have a lot more data behind their classifications.

Currently there is no data for diatoms or macrophytes in any water bodies; however, we can expect that in the Ramsey River, they both may be failing. The reason for this would be the poor phosphate levels and bad dissolved oxygen levels that have been determined here. These levels are, in-turn, affecting the invertebrate numbers and diversity, therefore causing this category to be classed as moderate. Currently, fish are classed as good within this waterbody, but with other factors that could put pressure on them; this status is likely to deteriorate if no action is taken. Water quality is the main driver of the problems in this waterbody and there are multiple factors that contribute to this low water quality:

  • Invasive Carp- Unfortunately, carp have been introduced to this waterbody. Carp are known for causing deterioration of water quality and therefore eradication is the only option for removing their impact.
  • Environment Agency Pumping Station- This pumping station is likely to be having an effect on the flow rate of the river. A disrupted flow will impact dissolved oxygen levels as water is aerated less.
  • Diffuse Pollution from Arable Fields- Run off from agricultural land will bring phosphates in to the waterbody. This can be addressed by working with landowners to introduce methods to reduce run off and intercept phosphates.

Unfortunately there is currently no data on the state of the water quality at Stutton Brook, therefore its present state cannot be commented on; tests prior to 2011 show that phosphate levels are moderate with dissolved oxygen being classified as poor. This waterbody does fail for fish, and it is suggested that this may be due to barriers in the water course that are preventing migration, causing isolated populations and therefore pressure on the overall fish population. There are barriers currently at Stutton Bridge and Keebles Grove and there are now aims in place to improve passage at both of these barriers.

Holbrook is different to the other waterbodies in this catchment as it has a high classification for both phosphate and ammonia. Dissolved oxygen is classified as moderate, although there is dispute over this as the currently classification is only based on one monitoring point. Morphology and hydrology are both classified as moderate, this is likely to be because the water body is highly modified, which is therefore having an impact on flow. This modification is also contributing to a poor fish classification as they are met with barriers to migration, isolation, reduced habitat availability and high sedimentation in parts of the brook.

Overall, this catchment requires a lot more data to be collected in order to reach certain classifications. Work can already start to be done to address the issues that have been identified, but further investigations are important to ensure any work that is taken forward can be as effective as possible.

 

 

 

 

 

 

 

 

Website key stakeholders:

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Design by LTD Design Consultants and build by Garganey Consulting based on an original concept by Herts and Middlesex Wildlife Trust