"A Clear Future for our River"

Projects

Electrofishing surveys on the Wellow Brook

Thanks to funding from the Bristol Avon Catchment Partnership, BART carried out electrofishing surveys on the Wellow Brook this summer.  The study was undertaken to provide part of a set of data being collected to monitor improvements made by the boulder weir removal (read more about this here) and also a number of in stream habitat improvements made following funding from the Environment Agency.

On 6th and 7th June 2017, BART worked with Five Rivers Environmental Contracting to conduct electrofishing surveys on the Wellow Brook between Stoney Littleton and Wellow.  Electrofishing is a fish surveying technique combining a mixture of electrical current with a known water conductivity to temporarily stun fish in order to measure and document the population and community fish statistics at a freshwater location.

The following fish were found during the survey:  Brown trout, European eel, Brook lamprey, Stone loach, Common bullhead, Minnow, 3 spined stickleback and 9 spined stickleback.  During the surveys, most fish were found at pinch points where both fish cover and flows increased significantly compared to otherwise straightened and canalised sections.  Recommendations were made to increase pinch points in these straightened sections of the river and introduce woody debris.  The findings of the electrofishing study were used to inform the river restoration works carried out by BART on the Wellow brook in September and October 2017. Read about the river restoration work to improve fish habitat here!

 

A summer of ecological surveys

BART’s ecologist, Jessy Grant, has been busy this summer with lots of exciting ecological monitoring projects for both BART and external clients.  Here’s more information about some of our ecological work!:

  • Case study:  Wellow brook pre-restoration surveys – Summer 2017

BART carried out a suite of surveys on the Wellow brook at Stoney Littleton in summer 2017 to assess the ecological conditions of the brook before beginning river habitat restoration works in September 2017.  (To read about the habitat restoration project please click here). The area where restoration was going to take place was divided into an upstream and downstream section.  In each section Jess undertook one macroinvertebrate survey, one 100m macrophyte survey and a 400m River Corridor Survey covering the whole section.  It is hoped that with further funding post restoration, monitoring will be carried out one year after the river restoration works to measure the changes. 

Analysis of the data found that the Wellow Brook at Stoney Littleton has a good diversity of macroinvertebrates and macrophytes present.  Water Framework Directive (WFD) classification results found the brook to be at “good status” for macroinvertebrates and macrophytes in the downstream stretch and “high status” for macrophytes and macroinvertebrates in the upstream stretch.  Recommendations were made for river restoration works in the straight sections of the brook where flow is slow, the substrate is predominantly silt and there is heavy shading.  The findings of the surveys informed the September in-stream restoration works, which helped to increase sinuosity and channel diversity in straighter sections of the channel where the flow is slower and decreased over-shading of the channel. 

  • Case study:  Corston and Newton Brooks’ environmental assessment and walkover surveys – Spring and Summer 2017

In spring and summer of 2017 the Duchy of Cornwall funded BART to undertake environmental monitoring on the Corston and Newton Brooks, west of Bath.  The aim of the monitoring was to record and assess the current environmental conditions of the brooks within the Duchy of Cornwall’s land and to make recommendations for potential improvements to the waterbodies.  Monitoring included macrophyte surveys, macroinvertebrate surveys, water quality surveys, waterbody assessment walkover surveys, wet weather walkover surveys and tree surveys.  The data and findings are being put together in a report for the Duchy of Cornwall, so watch this space for further information!

 

 

 

 

 

 

 

A month on the Wellow Brook

After working on the Wellow Brook for the whole of September we have finished this section of river restoration work! We have had a fantastic few weeks building in-stream habitat structures in Somerset at Midsomer Norton and Stoney Littleton, which will provide habitat for juvenile fish, scour sediment from riverbed gravels and create flow diversity by forming shallow areas and deeper pools.

In total we built 34 structures which is a tremendous achievement!

A completed woody debris structure

The woody debris structures, made from coppiced trees from the riverbank, will gradually accumulate sediment over time which will re-meander the channel within its banks and re-naturalise the stream. Within a few days we could already see sediment accumulating on the structures and the river meandering around them, so we’re looking forward to monitoring them in future. Re-naturalising the channel will improve habitat for invertebrates and fish, and therefore benefit all of the other wildlife which relies on this river too.

Volunteers at Midsomer Norton

BART would like to say a huge thank you to all of the volunteers who got involved in this project, without you we could not have achieved anywhere near as much as we did! Building the structures is hard work but all of our wonderful volunteers were happy to get stuck in and remained enthusiastic, even when it rained!

Working hard to secure those posts!

Another thank you to the Environment Agency Asset Performance Flood and Coastal Risk Management team who joined us for a day at Stoney Littleton, you were a great help!

Happy volunteers!

We hope to keep working on this stretch of river, and are continuing to look for further opportunities where improvements can be made…so watch this space!

A final thank you to our funders who made this work possible. To the People’s Postcode Trust for funding the restoration work in Midsomer Norton, and the Environment Agency and Bristol Avon Catchment Partnership for funding the work at Stoney Littleton.

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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!