Stour

Fish Passage

There are multiple structures in this waterbody which prevent fish movement. There is a 1.7km stretch beyond the reservoir where the fish population has become completely isolated over the last 10 years. Isolated populations are often more susceptible to disease and other pressures.

Flow

Flow is heavily impacted in this waterbody because of two main factors. One is the impoundment of water at Alton Reservoir. The second is a flood protection structure which also affects the natural flow of water. The reduced flow means that the dissolved oxygen content in this waterbody is at poor status.

Physical modification

A combination of all of the previous pressures, and the general maintenance of the river, means that the morphology of this river is classified as moderate.

Fish Passage

There are multiple barriers in this waterbody which are preventing fish movement. There were lower than expected populations of fish in this waterbody when it was surveyed, this was especially true for roach, chub and dace.

Flow

This waterbody has a relatively low flow which could be due to the groundwater abstraction that takes place locally. This low flow could be having an impact on fish and invertebrate populations, but there are uncertainties about how much of an impact this low flow may be having.

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. Diatom populations also indicate higher than optimum pollution levels.

Fish Passage

Fish populations on this stretch of river have decreased and numbers are lower than expected. This is likely to be because of maintenance activities on the river that have reduced habitat availability and prevented fish from being able to inhabit the whole stretch of river. The maintenance includes dredging which is usually done to protect properties from flooding.

Flow

There is currently no information on how this river flows, although the hydrology at the site has been classed as moderate.

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. Diatom populations also indicate higher than optimum pollution levels.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Fish Passage

There are a few structures on this waterbody which may impact on some fish and their ability to migrate along the river.

Invasive Species

Himalayan Balsam has been most recently recorded on this water body in 2013 . This pretty plant, with pink flowers, is fast growing and hardy. It covers river banks and shades out native plants. In the winter, Himalayan Balsam will die down, leaving bare banks that are susceptible to erosion.

Physical Modification

There are a range of physical structures on this waterbody including flood protection structures, a mill and other barriers. These physical structures are contributing to the lower than expected fish populations that are seen in this waterbody.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from.

Diffuse Pollution

Phosphate levels in this waterbody are currently classified as poor. This phosphate is likely to be coming from diffuse agricultural sources.

Invasive Species

Signal Crayfish have been most recently recorded on this water body in 2003, 2005 and 2014. 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.
The invasive signal crayfish are present in this waterbody.

Point Source

Phosphate levels are also impacted by the local sewage treatment works which discharges into this waterbody.

Diffuse Pollution

This waterbody has developed problems with phosphate, ammonia and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Invasive Species

The invasive signal crayfish are present in this waterbody. The signal crayfish are likely to be causing problems for invertebrates which have fluctuated between moderate and good status. Before 2011, this site held a healthy population of white-clawed crayfish which were unfortunately lost to crayfish plague.

Physical Modification

Channel maintenance activities often reduce river bed and margin habitats.

Point Source

This waterbody has developed problems with phosphate, ammonia and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Diffuse Pollution

This waterbody has developed problems with phosphate, ammonia and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Physical Modification

This river stretch, along with many others in this catchment, has been historically modified.

Point Source

This waterbody has developed problems with phosphate, ammonia and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Invasive Species

Signal Crayfish have been most recently recorded on this water body in 2000 . 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.

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. There are several consented sewage discharges along this waterbody, including one major sewage treatment works.

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Physical Modification

Channel maintenance activities often reduce river bed and margin habitats. This river stretch, along with many others in this catchment, has been historically modified.

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. There are several consented sewage discharges along this waterbody, including one major sewage treatment works.

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. Diatom populations also indicate higher than optimum pollution levels.

Fish Passage

This river has been historically altered and this means that there are many barriers to fish migration. Removal of these barriers would not necessarily allow the fish populations to recover and would also incur high costs

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. Diatom populations also indicate higher than optimum pollution levels.

Diffuse Pollution

This waterbody is surrounded by mainly arable fields; the run off from these fields often contains a range of pollutants including phosphate.

Flow

Flood protection via a pumping station at this site has an impact on the flow within the waterbody. This reduction in flow causes real problems with dissolved oxygen levels in the water.

Invasive Species

There is a problem with Carp in this waterbody. The carp are contributing to the reduced dissolved oxygen levels.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Invasive Species

Turkish Crayfish have been most recently recorded on this water body in 2006, 2007 and 2009. Turkish 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.

Giant Hogweed has been most recently recorded on this water body in 2012. This plant has been in the news a lot more recently due to the horrific burns that its sap can give the skin. This invasive plant is so large that it is able to shade out other native plants.

American Mink have been most recently recorded on this water body in 2010 . 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.

Signal Crayfish have been most recently recorded on this water body in 2000, 2007, 2009, 2013. 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
Physical modification
This river stretch, along with many others in this catchment, has been historically modified.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Flow

Models have shown that there is likely to be issues with the hydrology in this waterbody.

Invasive Species

Himalayan Balsam has been most recently recorded on this water body in 2012. This pretty plant, with pink flowers, is fast growing and hardy. It covers river banks and shades out native plants. In the winter, Himalayan Balsam will die down, leaving bare banks that are susceptible to erosion.

Physical Modification

This river stretch, along with many others in this catchment, has been historically modified.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. This waterbody also has problems with its invertebrate populations; this may be linked to the high phosphate levels.

Fish Passage

Multiple physical structures cause barriers to fish, this includes a section of water impoundment.

Flow

Multiple physical structures and a lack of in-channel vegetation have caused un-natural flows. This could be having a negative impact on the biology of the waterbody.

Invasive Species

Giant Hogweed has been most recently recorded on this water body in 2015. This plant has been in the news a lot more recently due to the horrific burns that its sap can give the skin. This invasive plant is so large that it is able to shade out other native plants.

Turkish Crayfish have been most recently recorded on this water body in 2007, 2009, 2011 and 2015. Turkish 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.

Physical Modification

A range of measures have previously been put in place for this waterbody, to improve the bankside vegetation, remove hard bank reinforcements, increase channel diversity and remove structures. These measures have not been taken forward.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as poor. Unfortunately there is no data to suggest where these problems are originating from. This waterbody also has problems with its invertebrate populations; this may be linked to the high phosphate levels.

Diffuse Pollution

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Point Source

This waterbody has developed problems with both phosphate and dissolved oxygen levels which both contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. Reduced oxygen levels are often common in summer months because of reduced river flows, higher water temperatures, increased oxygen demand due to increased biological activity and higher effluent proportions in watercourses.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. This waterbody also has problems with its invertebrate populations; this may be linked to the high phosphate levels.

Physical Modification

This river stretch, along with many others in this catchment, has been historically modified.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately there is no data to suggest where these problems are originating from. This waterbody also has problems with its invertebrate populations; this may be linked to the high phosphate levels.

Diffuse Pollution

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately, there is no data to suggest where these problems are originating from.

Fish Passage

This river has been historically altered and this means that there are many barriers to fish migration. Removal of these barriers would not necessarily allow the fish populations to recover and would also incur high costs.

Point Source

This waterbody has developed problems with phosphate levels which contribute to its overall rating as moderate. Unfortunately, there is no data to suggest where these problems are originating from.

Diffuse Pollution

There is no data due to a lack of water testing and investigation within this waterbody.

Fish Passage

There is no data due to a lack of biological monitoring within this waterbody.

Flow

The flow on this waterbody has been classed as moderate. The reason for this classification is due to groundwater abstraction that takes place within this waterbody.

Invasive Species

There is no data due to a lack of biological monitoring within this waterbody.

Physical Modification

This waterbody has been modified historically which means that it is classified as moderate under this category.

Point Source

There is no data due to a lack of water testing and investigation within this waterbody.