Property:Monitoring surveys and results
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R
Wednesday 30 April 2014 (update)<br>
Following winter flooding and sustained high water levels, the work has stood up really well to the demanding weather. Still, there was some repair work and tidying up to do at the Fifield site. Over the winter some trees had blown down and were blocking paths and posing a potential risk of flooding and damage to the restoration work. The main problem was a large tree branch which had fallen across a footbridge and the bottom end of the reach. After consulting with landowners, the fishing club that manages the site and the Environment Agency, it was decided that the wood should be used to create further habitat at the lower end of the site, and at the same time remove the risk. +
B
When the cleared channel portion is widened from 2m to 4m, this results in a significant change in surface water level slope. A widening from 4m to 6m does not have such an effect. The portion of the river in which the water can flow freely can be reduced significantly reduced when sediment builds up on the edges of the channel. +
W
Whilst empirical evidence relating to the success of the project is not yet available – the project was only finished by the end of 2014, certain indications were noticed within weeks of project completion and these suggest that we have achieved many of the goals set for the project.
For example, in more than 10 areas where structures have been installed to increase bed dynamics and re-energize erosion-deposition equilibriums, the evidence of scour, cleaning and sorting of gravels by the river is already clearly visible.
We cannot yet prove that this has led to an increase in fish spawning, but we can show that the gravels are now suitable for that purpose, whereas before they were concreted. Similarly, the dozen of brushwood structures installed to trap sediments and narrow the channel are clearly doing so. There is a higher flow velocity around the structures and the accretion of silt within them, is clearly visible. This has created in-channel sinuosity with the structures (woody debris and brushwood mattresses) deflecting flow from bank to bank from what was a uniform flow.
Further indication that the river restoration has already had a positive impact has been provided by chance meetings with fishermen on the river bank. Feedback has taught us that the fishing has become much more varied in the months after the work was delivered: a greater number of productive fish lies and much more variation in habitat and higher numbers of Grayling caught.
A more thorough evaluation of the project can (and will) be undertaken in the next year(s), when results from several monitoring efforts will become available.
Prior to the project a topographical survey of the river bed and banks was undertaken. This survey will provide a baseline comparison when we repeat this survey in two and five years’ time. That will tell us whether we have indeed increased variation in channel morphology.
The long running Environment Agency programme for Atlantic salmon redd counting on the river will be continued. This will enable a pre- and post-project comparison of redd location and abundance telling us whether we have improved spawning conditions.
Repeated Fixed Point Photography (FPP) is being used to assess the establishment and development of river enhancement structures – such as hinged willows. Photos are taken at least twice a year. Although in itself very valuable, FPP cannot be used to evaluate the actual success in terms of reaching SAC, WFD targets. Data from biological monitoring are essential for that. Ultimately WFD and SSSI monitoring carried out on larger spatial and time scales will answer whether this project has contributed to the water body meeting these objectives.
H
With utilisation of plant materials and resources already on site, minimising mobilisation costs for river restoration; to improve habitat diversity in a heavily modified waterbody; to give greater flow diversity helping to address low dissolved oxygen issues.
By addressing a low dissolved oxygen concentrations and mitigation measures needed for heavily modified designation. +
D
Work completed in April 2022. To date the Clyde River Foundation undertook monitoring before and during works and have found all key fish species in the area - lamprey, trout, eel and salmon. We hope to see these species thriving in future years. +
S
Working with University of Brighton, the project has set up a long term monitoring programme to look at and assess geomorphological changes, seed dispersal of Himalayan Balsam, and hay meadow restoration techniques. +
R
Working with landowners to create species-rich grassland buffer strips to reduce diffuse agricultural pollution from adjacent arable land through absorption of agricultural run-off. We installed hinged large woody debris to improve channel conditions for benefits for fish spawning and aerate flows. These will hopefully start to show an improvement from a WFD perspective through the habitat improvements.
The projects main success has been the establishment of the Idle Management Partnership Group. Although the group has taken time to develop and have a clear purpose, it has been beneficial to have landowners as well as partner organisations meeting together to discuss what's best for the river. +
B
http://www.vannportalen.no/globalassets/vannregioner/vest-viken/vest-viken---dokumenter/vannomrader-i-vest-viken/siljan-farris/dokumenter/fagrapporter/biotop--og-flomtiltak-i-mykleelva-og-vanebuelva_rapport.pdf +
R
https://uni.no/media/manual_upload/LFI_235.pdf +
H
https://www.radgivende-biologer.no/wp-content/uploads/2019/10/2910.pdf
https://docplayer.me/50826638-Habitatkartlegging-i-bortneelva-bremanger-kommune.html +
R
https://www.vann-nett.no/portal/#/waterbody/006-70-R +
T
https://www.vann-nett.no/portal/#/waterbody/006-70-R +
R
https://www.vann-nett.no/portal/#/waterbody/006-74-R +
L