"A Clear Future for our River"

Projects

Bringing back curves to the River Biss

September is always a busy month for BART with fieldwork and river restoration, and this year was no exception. As we need to avoid the trout spawning season which begins in October, September is always jam packed with long days out on the river and we have definitely been making the most of it!

Over the weekend BART have been doing river restoration with the Friends of Biss Meadows Country Park in Trowbridge. They are a community conservation group formed of dedicated volunteers who protect the plants and wildlife at the country park. They also run wildlife walks throughout the year and have monthly working parties so are kept busy all year round!

Working together with the Friends group and other volunteers we restored in-stream habitat diversity to a section of the River Biss, which created a more diverse flow within the river channel which had  previously been overwidened and overstraightened. The berms which the volunteers built will create new areas of habitat by forming shallower bays which will gather sediment and form new areas of bankside, as well as faster flowing sections of the channel which creates flow variety.

The team built woody debris structures out of coppiced tree limbs which are then fixed into place by the bank using chestnut stakes. The tree limbs are angled into the channel and brash cut from the tree limb fills in the structure from the bankside.

These structures will provide refuges for juvenile fish as the river slows as it flows through it, and acts as a nutrient trap where the water is warmer which again gives juvenile fish a helping hand in finding food. The structures also trap silt which would otherwise be suspended in the channel, and promote scouring of silt from gravels on the riverbed which is essential for fish spawning.

The conditions were pretty tricky to work in with deep water full of silt after the recent heavy rain, so an extra well done and thanks to all the volunteers and the Friends of Biss Meadows!

Thanks to People’s Postcode Lottery‘s Awards for All for funding this project with Friends of Biss Meadows Country Park.

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Work begins to improve the Wellow Brook

So here we are in September, our busiest month of the year for in-stream habitat improvement works and it feels like just yesterday we were finishing up our works on the Bristol Frome at the end of February. How quickly has that Summer (or lack of it!) flown by!? We conduct most of our in-stream habitat work, which largely involves adding woody materials to rivers, before October to avoid the trout spawning season (October to March), where any disturbance of sediment may affect egg survival. By avoiding this season, we can be sure that our habitat work only has positive impacts on juvenile fish recruitment. This is different for coarse rivers whose ‘closed season’ is 15th March to 15th June inclusive.

We are extremely lucky to have received funding from multiple funders (HDH Wills, People’s Postcode Trust, the Bristol Avon Catchment Partnership and the Environment Agency) to deliver habitat improvement works along a significant length of the Wellow Brook over 5 weeks. These improvements are taking place around the areas of Midsomer Norton, Stoney Littleton and Wellow.

Volunteers at work installing woody debris in the Wellow Brook

This woody debris work is happening for a variety of reasons along the brook, including any previous modifications to the channel (such as straightening, overwidening and artificial banksides), low fish numbers (as deduced from Environment Agency and BART electrofishing surveys) and as a follow on to our removal of 3 boulder weirs at the end of 2016. However, the general benefits are similar wherever these structures are placed and include:

  • Fish cover for juvenile fish, reducing predation by larger fish, birds and mammals, increasing recruitment rates and therefore population numbers.
  • The formation of shallow bays which act as warmer water nutrient traps and escape from faster flowing waters, providing essential food sources for juvenile fish and further increasing recruitment.
  • Acting as silt traps to reduce turbidity within the water column and reduce fish stress, therefore improving survival.
  • Increasing areas of shade within the river to mitigate for warmer waters (and therefore reduced oxygen content) from climate change.

An example of woody debris habitat creation from last years work on the River Marden, Calne.

These works simply replicate the processes and benefits that occur when a tree falls into the river, but in a way that ensures no unwanted erosion or enhanced flood risk. Over time, silt in the river will accumulate on the structures, they will vegetate and they will form part of the bankside in a more natural, meandering form than before the works. This method is much better than hard engineering works using man-made materials as it creates more diverse habitat, is more natural, requires less carbon dioxide to produce, is cheaper and provides an extra win of coppicing overshaded rivers.

We are also pleased to announce that we have been selected to go forward to the Tesco Bags of Help public vote, where Tesco customers around the Bath area will have the chance to vote to extend these improvements to the urban section of the Wellow Brook through Radstock. This will provide a crucial link to join up our habitat improvement works, which will result in further enhanced fish populations. More information here.

These works are part of our larger Wellow and Cam initiative which is taking a catchment approach to improving the length of the Wellow and Cam Brooks. Other upcoming elements to this initiative include fish passage investigations later in the year, landowner meetings and farmers lunches to discuss how we can work together to reduce diffuse pollution levels in the area.

We are very grateful to those people who have already volunteered with us on this project and those of you who have signed up to volunteer over the next 5 weeks. A massive thank you is also due to our funders HDH Wills, People’s Postcode Trust, the Bristol Avon Catchment Partnership and the Environment Agency for funding these works!

 

 

 

 

Bristol Avon Waterblitz – the results!

The results are in and the Bristol Avon Waterblitz is now over! This is the first year that BART have run the Waterblitz, and it was a great success with 176 water quality samples taken and a total of 375 people involved!

Thanks to funding from the Bristol Avon Catchment Partnership and the Greggs Foundation, we worked in partnership with FreshWater Watch to get as many people as possible to take a water quality sample from their local river or stream. The water quality testing kits measured the concentration of nitrates and phosphates, which are naturally occuring chemicals in rivers and are essential for life, but in high concentrations caused by sources of human pollution they can degrade water quality and harm aquatic life.

We had a great response to the Waterblitz, with many volunteers keen to contribute and learn more about the quality of their local river. Samples were taken from all across the Bristol Avon catchment, and it was so interesting to find out how the concentration of nitrates and phosphates varies in different water bodies. The results collected will aid us in gaining a better understanding of the state of the river environment, and provide an evidence base for future work.

 

A Duke of Edinburgh group from Playwood Forest School getting involved with the monitoring

To view the summary of the results, including graphs, maps and statistics please click the links below:

Waterblitz results page 1

Waterblitz results page 2

To see the results on the Freshwater Watch interactive map, please follow the link below:
https://freshwaterwatch.thewaterhub.org/bristol-avon-water-blitz

A big thank you to all of our volunteers, the results you have collected are invaluable in helping us determine the health and quality of the freshwater bodies within the Bristol Avon catchment.

We hope that all those who took part enjoyed sampling your local river, and found it interesting to learn more about water quality. If you would like to get more involved in protecting and monitoring the water environment, see the links below for more information:
– Bristol Avon Rivers Trust (BART) – Riverfly monitoring and volunteering as a BART Beacon

Bristol Water and Wessex Water – Learn more about what you can do at home

 

 

 

 

 

 

 

Somerset Frome Sediment Pathways Project

BART have completed a very interesting and useful project funded by the Bristol Avon Catchment Partnership this Spring.

Sediment entering watercourses can have a detrimental effect on aquatic ecology, including fish and invertebrates.  This project has used predominantly field surveys to identify where sediment is entering watercourses in the upper Somerset Frome catchment and to determine the sources of this sediment.

The survey period of the project drew to a close at the end of March, with over 191 locations visited on the upper Somerset Frome looking for potential sediment pathways. Sediment pathways have been recorded at over 110 locations on the main river Frome and its tributaries including Redford Water, the Rodden Brook and the Marston Brook. At each location the source of the sediment pathway has been determined where possible and a diffuse pollution grade has been allocated to identify the severity of the pollution pathway.  Photo 1 shows an example of sediment entering the Rodden brook via a pipe during a wet weather event.

1. Pipe discharging into the Rodden Brook

The most common, and sometimes very severe pollution pathways seen as part of this project have included poaching and trampling by cattle and horses (photo 2), muddy farm tracks, gateways and yards, maize grown to the edge of watercourses with very little buffer zone (photo 3), discharging pipes and road run off. The most severe pollution pathways have been re-visited during or shortly after heavy rain to collect further evidence.

 

2. Poaching and soil compaction

3. Lack of buffer alongside a maize field resulting in run-off into the Rodden Brook

Alongside the field surveys the Somerset Frome project included a public engagement campaign to increase local awareness of the issues surrounding erosion risk and diffuse pollution and to build stronger relationships with the landowners surrounding the river Frome. As part of this work a farmers’ lunch was held on 9th March 2017 in the upper Frome area. This lunch brought together local farmers, BART and Farming and Wildlife Advisory Group (FWAG) to discuss sediment pathway issues in the catchment and to encourage partnership work in the future.

Thank you to all interested individuals and organisations who have been involved in the project and sent in information to help us prioritise areas to visit.

The report is now available to view but is too large to host on the website. If you would like a copy then please email our Project Officer Harriet at harriet@bristolavonriverstrust.org

We are really keen to continue work with the very helpful landowners in this area and to help take the actions necessary to remove some of the problems we spotted. Many are potentially small and low cost but would add up to a significant decrease in sediment entering the river if they are fixed. We are currently seeking funding to make this happen. ​

Duchy of Cornwall river surveys

BART have been busy over the last few months undertaking a variety of river surveys on Duchy of Cornwall estate land near to Bath, including:

  • In-stream and riparian habitat surveys
  • Surrounding land use investigations to assess impacts on water quality.
  • Water quality monitoring
  • Macroinvertebrate surveys
  • Macrophyte surveys
  • Riparian tree surveys

BART’s Aquatic Scientist Jess running water quality tests with BART volunteer Jenny.

Findings from these surveys will be used to create recommendations for improvement works to both in-stream habitats and surrounding land use.

Assessing land use, riparian shading and other factors on the Corston and Newton Brooks.

We are grateful to the Duchy Estate for supporting us in this research and for their enthusiasm to protect our rivers.

BART are able to complete these and a number of other types of surveys throughout the Catchment. If you own or rent land with a river or stream, please feel free to get in contact if you would like to arrange a site visit and/or discuss survey and improvement opportunities by emailing harriet@bristolavonriverstrust.org