32. Point source pollution project
Aim:
Involve people with their local waterbodies; Improve water quality; Work together
Mapping and verifying the entry points of pollution into our rivers.
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31. Rickmansworth Aquadrome (Local Nature Reserve) Project
Aim:
Involve people with their local waterbodies; Improve wildlife corridors
This project will enhance, nurture and protect the Aquadrome: It aims to develop and achieve a balance so nature can flourish, and visitors can connect with and discover beautiful, unique habitats, whilst understanding the importance of the site’s heritage.
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30. Denham Weirs Eel Passage Improvements
Aims:
Improve wildlife corridors
Weir modification to provide eel passage.
Three barriers were identified: one on the River Colne at Denham Lodge in New Denham and in Denham Country Park where the River Frays and Colne meet. Eel Passes were successfully installed, to allow eels to negotiate the weirs in all three of these positions. Groundwork South worked in partnership with Affinity Water, Thames Water and The Environment Agency (with additional funding from Grundon) to resolve barriers to the migration of European Eels.
Find out more here:
Denham Eel Pass Project
and here Denham Eel Passes Installed
Refer also to Project 2. Frays and Colne Weir
29. Floating Pennywort Control in the Colne Catchment
Aim:
Control invasive non-native species; Involve people with their local waterbodies; Improve wildlife corridors; Improve water quality; Manage flow; Work together
This project proposes to tackle the problem of the non native invasive species Floating Pennywort that has successfully infested the Colne Catchment through a) biological control delivered by CABI and b) physical removal & community engagement.
Floating Pennywort is an Invasive Non Native Species that has a phenomenal growth rate – particularly in nutrient rich watercourses (20cm a day in peak summer conditions), it can suffocate watercourses to the detriment of wildlife and people.
Floating Pennywort covers large areas of the River Colne and its tributaries and is spreading, causing serious concern to angling clubs, conservationists and local communities.
For more information, see Floating Pennywort Public Leaflet
Biological Control
Due to previous work of Colne Valley Fisheries Consultative, Environment Agency, Groundwork South and others the Colne has been selected as a trial location to establish a Weevil from South America (Pennywort’s native area) that feeds exclusively on Floating Pennywort. Biological control has the added advantage that it can get to Pennywort in parts other control methods can’t reach - such as amongst fallen trees or branches in the water. After extensive research and trials a licence has been obtained from DEFRA to release the Weevil in the Colne, one of only three pilot areas in the UK. It takes approximately 5 years to successfully establish a self sustaining population in the wild to acclimatize and adapt to the habitat and build up some resilience. The first five years is an investment for all those years that follow. We are currently in year 2, this project will focus on years 3-5 starting in April 2023.
Physical Removal & Community Engagement
This will take place involving local communities in physical control to keep on top of the infestation in the areas away from the Weevil release sites. We will undertake at least 30 work sessions/year at a variety of sites across the northern part of the Colne Valley Regional Park from Rickmansworth to Denham/Uxbridge focusing on the River Colne and its side channels and the River Misbourne downstream of Chalfont St Peter. Physical removal will be away from Weevil release areas because we don’t want weevils being removed with the Pennywort. Volunteers will be trained to carry out monitoring so that they can recognise Weevil presence as their range and distribution grows.
Outputs over 3 years
Support for the CABI research programme to ensure a successful viable population of Weevils. The research outputs will include further understanding of the success of the Weevil as a biological control in the UK. This will provide a case study that could lead to a long term UK wide solution for Floating Pennywort, a damaging and costly invasive species.
At least 100 Pennywort control volunteering sessions involving at least 5,000 person hours. Community engagement via articles in local publications and social media and conversations (‘door knocking’) with riparian landowners to educate and encourage positive action.
Over 10km of watercourse directly improved for biodiversity. Leading to natural control in perpetuity across the Colne Catchment which includes 100’s of km of watercourse.
The Case for investment
The environmental case - An invasive non native species which excludes naturally occurring native species and negatively impacts on the water environment – physically (shading and occupying space, chemically pH) and shading impacts/temp control. Detrimental to the watercourse and the Water Framework Directive.
The community case - impact on angling and the visual appearance/amenity value of rivers. There is high public concern and many offers to help. These offers need support and guidance including to stop well-meaning actions inadvertently causing more problems eg letting Pennywort float downstream, putting it in council green waste bins or removing beneficial species such as Watercress.
The business case. Impact on fisheries, navigation & other commercial interests. However, the key business case for investment in this project is the fact that a Biological Control agent is now available, which can provide a cost effective means of removal given the size and scale of the task.
We have launched and Appeal to help fund this project: Donate here to help local rivers flow freely again. Thank you.
28. Denham Country Park Backwater
Aim:
Improve wildlife corridors; Work together
Working in partnership to create a backwater on the River Colne in Denham Country Park.
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16. Reedbed restoration at Maple Lodge Nature Reserve
Aims:
Improve wildlife corridors
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26. River Restoration at Denham
Aims:
Improve wildlife corridors
River and ditch restoration in pursuit of Water Framework Directive improvement
Remove trees, other woody scrub and bramble from sections of the Fray’s River and ditches on Fray’s Farm Meadows London Wildlife Trust (LWT Reserve). Work on the Fray’s River was carried out in February 2016 to remove overhanging branches but retaining woody habitat already in the river. The extra light allowed on to the river should encourage the growth of marginal plants that provide ideal water vole habitat while the woody material in the river will act as nursery areas for small fish. The photographs show the situation on the river immediately before and after the work.
25. Colne Valley Water Vole Conservation
Aims:
Improve wildlife corridors
Maintain and extend the surveying of water bodies to look for evidence of water voles and hence increase knowledge of the presence and absence of water voles in the valley. Increase the number of rafts to monitor and control American mink, the prime predator of water voles. Wherever possible improve habitats to benefit water voles and other riparian wildlife.
15. Lower Colne Mink control
Aim:
Control invasive non-native species; Improve wildlife corridors
American Mink monitoring and control for the benefit of Water Voles and other native wildlife.
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3. Stockers Weir
Aim:
Improve wildlife corridors; Manage flow
Weir modifications and bypass channel to create fish passage and improve flow upstream of the weir.
Options for the weir and potentially impacted surrounding waters are the subject of hydrological study and any action will be determined by the outcomes of that.
14. Uxbridge Alderglade
Aims:
Improve wildlife corridors
Habitat enhancements and access improvements at Uxbridge Alderglade Nature Reserve.
13. Black Park Alder Carr
Aims:
Improve wildlife corridors
Habitat enhancements in the Alder Carr to slow drying out of the wet woodland Site of Special Scientific Interest.
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12. Colne Valley Park short walks
Aims:
Involve people with their local waterbodies
Update and reprint the series of 20 short walks throughout the Colne Valley Park
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11. Floating Pennywort removal, Denham
Aims:
Control invasive non-native species
Programme to remove Floating Pennywort from the Colne at Denham
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6. Connecting People with the Colne Valley
Aims:
Involve people with their local waterbodies
The project aimed to encourage local people to discover wildlife in the Colne Valley through events, volunteering opportunities and new educational materials.
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10. Hardings Row Millenium Nature Reserve
Aims:
Improve wildlife corridors
Habitat enhancements and access improvements at this small nature reserve in Iver Heath.
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8. Springwell Reedbed
Aims:
Improve wildlife corridors
Habitat restoration for wildlife. Improved site signage and interpretation.
Springwell Reedbed is managed as a nature reserve by Herts and Middlesex Wildlife Trust in partnership with the owners, Affinity Water. It is the largest reedbed in the London area and has been restored to provide ideal conditions for those species associated with this habitat such as Reed Warbler, Water Rail, Harvest Mouse, Water Vole and Otter. Annual management includes cutting sections of the reed bed with a ‘Truxor’, an amphibious reed cutting machine.
Interpretation boards have been installed to provide information about the habitats and the species which live in them.
7. Rickmansworth Aquadrome
Aim:
Involve people with their local waterbodies; Improve wildlife corridors
Enhancments to Batchworth Lake and Bury Lake as part of site management plan implementation.
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9. Route to the Colne Valley Park from Uxbridge
Aims:
Involve people with their local waterbodies
Improve the paths from Uxbridge into the Colne Valley Park, its network of waterside paths and countryside attractions.
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5. River Colne Backwater
Aims:
Improve wildlife corridors
Backwater creation for mutual benefit of fishery and wildlife. To be undertaken as programme of habitat, access and landscaping enhancements along the River Colne walk
4. Colne at West Hyde
Aims:
Improve water quality
The Stretch of River is Fished by the Fisheries Angling Club. Over the last few years a decline in catches has been noted by the angling club. This section of river has been historically modified through the practice of dredging. With little to no in channel habitat for fry and juvenile fish species survival a project was worked up to provide back water habitat. This will provide Juvenile fish and adult fish a survival area in times of high flows and provide a safe warm nursey for juvenile fish with shallow marginal ledges. These ledges established emergent vegetation also providing cover for fish species form the risks of predation.
2. Frays and Colne weir
Aims:
Improve wildlife corridors
Weir modifcation to provide fish passage. This site in Denham Country Park, on the border of Buckinghamshire and Hillingdon, hosts two weirs that are located in two separate channels known as the Colne & Frays Offtake Weirs. Both of the weirs are used as Environment Agency telemetry stations as well as controlling the flow between the Colne and Frays rivers. For this reason, they could not be altered in any way that migh impact their primary purpose. The design and installation selected were: A) modular fed eel pass on the River Frays; B) Larinier fish pass with a separate channel for the modular fed eel pass.
Eel Passes were successfully installed, to allow eels to negotiate the weirs in both of these positions. Groundwork South worked in partnership with Affinity Water, Thames Water and The Environment Agency (with additional funding from Grundon) to resolve barriers to the migration of European Eels.
Find out more here:
Denham Eel Pass Project
and here Denham Eel Passes Installed
Refer also to Project 30. Denham Weirs Eel Passage Improvements
1. Grand Union Canal backwater
Aim:
Improve wildlife corridors; Work together
Creation of a backwater for mutual benefit of the fishery and biodiversity. A fish refuge/spawning area and haven for wildlife with shallow sloping edges, variable depth, steep banks for Kingfishers. Tree works to increase light to the backwater to encourage growth of marginal vegetation. Habitat enhancements along the edge of the Grand Union Canal.
27. Lower Misbourne habitat enhancements
Aim:
Improve wildlife corridors; Manage flow; Work together
River enhancements to improve habitat from upstream of the Colne Valley Park Visitor Centre to the confluence with the Colne.
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22. Higher Denham habitat enhancement
Aim:
Involve people with their local waterbodies; Improve wildlife corridors; Work together
Local volunteers completed the enhancement of the lower Misbourne near Higher Denham in May 2014, improving habitat for fish and wildlife.
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24. Misbourne Water vole monitoring scheme
Aim:
Control invasive non-native species; Involve people with their local waterbodies; Improve wildlife corridors
Following on from the discovery of water voles along the lower Misbourne a monitoring scheme was set up by BBOWT in 2009.
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23. Riverfly monitoring
Aim:
Involve people with their local waterbodies; Improve water quality
Volunteers from the Chiltern Society and Misbourne River Action monitor riverflies at 12 sites along the Misbourne. Monitoring began in 2011 and results are posted here.
21. Gerrard's Cross Golf Club - Channel restoration
Aim:
Involve people with their local waterbodies; Improve wildlife corridors; Work together
Project to remove weirs and concrete lining of river channel, enhance habitat and improve access for golf club users.
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Potential: Opportunity identified, further consultation required
Planned: Consultation, costing and/or fundraising in process
Ongoing: Project currently being implemented
Completed: Project finished
The Colne Valley Park is a mosaic of farmland, woodland, water and villages containing 125 miles of watercourse, 167 miles of paths and hundreds of green spaces.
Potential
Planned
Ongoing
Completed