Case study:Upper Witham Restoration: Difference between revisions
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{{Location | {{Location | ||
|Location=52. | |Location=52.92952349785008, -0.6281864911059154 | ||
}} | }} | ||
{{Project overview | {{Project overview | ||
|Status= | |Status=In progress | ||
|Themes=Fisheries, Flood risk management, Habitat and biodiversity | |Themes=Fisheries, Flood risk management, Habitat and biodiversity, Social benefits | ||
|Country=England | |Country=England | ||
|Main contact forename= | |Main contact forename=David | ||
|Main contact surname= | |Main contact surname=Hutchinson | ||
|Contact organisation=Environment Agency | |Contact organisation=Environment Agency | ||
|Contact organisation url= | |Contact organisation url=Environment Agency | ||
|Partner organisations=East Mercia Rivers Trust, formerly Lincolnshire Rivers Trust, Wild Trout Trust, National Trust, Grantham Angling Association Fly Fishing Section, South Kesteven District Council, University of Lincoln. | |||
|Multi-site=Yes | |Multi-site=Yes | ||
|Project picture= | |Project picture=Manthorpe wetted floodplain in winter 23.jpg | ||
|Picture description=Wyndham Park | |Picture description=Wetted floodplain at Manthorpe following restoration | ||
|Project summary=The Upper Witham has been subject to significant changes which have modified the river and its hydrological functioning. These legacy interventions have been damaging to habitat and with serious pollution incidents, climate change implications and invasive species threats, native species such as White Clawed Cray-fish and Brown Trout are at risk of local extinction. A ground water fed system has now also become far more reactive in response to an increase in storm intensity across the area. | |||
Habitat improvement, rejuvenating a self-regulating functional active river system has been an aspiration for stakeholders working in the catchment for some time. Initial attempts at improving in-channel habitat from 2013 (EA, WTT and GAAFFs) used hinged trees and berms to narrow the river and scour pools. In the lower reaches, downstream of Grantham, this provided habitat in a system where it had previously been removed and was a good addition. Reviews of work did however indicate that this approach was not always having the desired effect; linked to very resistant clay bed and banks, poor gravel supply, and a lack of floodplain connectivity. | |||
Lessons were learned and subsequent landowner and flood risk engagement took place. These were applied in the EA and NT’s Belton project which began in 2016 with imported gravels added at the time. This worked well and provided a blueprint for works in the nearby urban setting of Wyndham Park, Grantham (EA and SKDC in 2017). More urban projects in the town followed from the Rivers Trusts (Dysart Park 2020) and most notably the Blue Green corridor project led by SKDC with more gravels added, trees hinged, berms created, and wildflower and wetlands introduced widely along the river. Belton was revisited in 2023 where floodplain connectivity was increased through strategic floodplain lowering and reconnection using live and dead woody material as the driver for change. | |||
The scale and ambition of individual projects increased with a more recent focus on larger scale projects connecting rivers with their floodplains more frequently. Manthorpe flood bank removal in 2020 (WTT and EA), Upper Cringle Brook ‘stage 8’ 2022 (EMRT), Grange Farm Stage 0 restoration (EA 2021) and Colsterworth (EMRT 2023) system reactivation, as well as innovative techniques such as smaller size gravel augmentation downstream of weirs (2023, WTT and GAAFFS at Papermill weir). Three large scale weir easement projects have also taken place at Aubourn (2016), Great Ponton (2015) and Easton (2014). | |||
|Monitoring surveys and results=We have learnt a great deal about lowland restoration and have applied this learning as the projects have progressed. Valuable feedback has come from revisiting project sites and undertaking objective reviews e.g 2018 Wild Trout Trust report . This is how we identified the importance of gravel and floodplain connectivity. We have long term ecological data for sites in the river that indicate that habitat works play a part in the continued improvement and prevention of determination of the ecology e.g Foston Ford fish surveys. Other sites like Easton Park show the limitations of some of the early in-channel techniques particular for fish populations although other factors like pollution incidents and low flow may be playing a role. Trout Redd surveys also provide good supporting data. Other monitoring techniques we have used include geomorphological surveys and drone topographical surveys. As the larger projects continue to evolve, our understanding of the impact they are having continues to develop, but it is clear following the storm events of winter 23/24 that we are undertaking projects that are both sustainable and are returning dynamic river processes to a lowland system. | |||
|Lessons learn=To get maximum benefit from projects, in areas with less constraints, we needed to look wider than interventions focused just within the channel and consider the floodplain as well. Further learning for individual projects can be found in the project specific case studies. | |||
|Project title=Upper Witham Restoration | |Project title=Upper Witham Restoration | ||
}} | }} | ||
{{Image gallery}} | {{Image gallery}} | ||
{{Case study image | {{Case study image | ||
|File name= | |File name=Pic 2 -Colsterworth October 2023.JPG | ||
|Caption= | |Caption=Colsterworth just after restoration. | ||
}} | }} | ||
{{Case study image | {{Case study image | ||
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{{Case study image | {{Case study image | ||
|File name= | |File name=Pic 3 -Wyndham Park Project Grantham 2019.jpg | ||
|Caption= | |Caption=Wyndham Park Project 2019 | ||
}} | |||
{{Case study image | |||
|File name=Mar 23 Photo.jpg | |||
|Caption=Cringle Brook after restoration. | |||
}} | |||
{{Case study image | |||
|File name=Pic 4 -Grange Farm Stage Zero Winter 2023.jpg | |||
|Caption=Grange Farm Stage Zero Winter 2023. | |||
}} | }} | ||
{{Image gallery end}} | {{Image gallery end}} | ||
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|Subcatchment=Upper Witham | |Subcatchment=Upper Witham | ||
}} | }} | ||
{{Site}} | {{Site | ||
{{Project background}} | |Name=Upper Witham Restoration | ||
{{Motivations}} | |WFD water body code=GB105030056780, GB105030051570, GB105030051560 | ||
{{Measures}} | |WFD water body name=Upper Witham - Headwaters to Confluence Cringle Brook, Upper Witham Confluence Cringle Brook to Confluence Brant and Upper Cringle Brook | ||
|Pre-project morphology=In general - Disconnected from floodplain, lack of wood, lack of gravel and gravel supply. | |||
|Reference morphology=Lower Cringle Brook | |||
|Desired post project morphology=In general and unconstrained areas - More connected floodplains, gravel and wood | |||
|Heavily modified water body=No | |||
|Protected species present=Yes | |||
|Invasive species present=Yes | |||
|Species=Brown Trout, Otters, Water voles and Native Crayfish | |||
|Dominant hydrology=Ground Water System | |||
|Dominant substrate=Clay, | |||
|River corridor land use=Livestock and arable. | |||
}} | |||
{{Project background | |||
|Reach length directly affected=80000 | |||
|Project started=01/01/2013 | |||
}} | |||
{{Motivations | |||
|Specific mitigation=Land drainage, | |||
|Biological quality elements=Fish, | |||
|Physico-chemical quality elements=Phosphate | |||
}} | |||
{{Measures | |||
|Bank and bed modifications measure=Various in-channel measures e.g brushwood berms, tree hinging, | |||
|Floodplain / River corridor=Bed raising, floodplain lowering and floodplain roughening. | |||
|Planform / Channel pattern=Weir Bypass and removal | |||
|Management interventions=Changes to floodplain management practice | |||
|Social measures=Community engagement and education e,g River School. | |||
}} | |||
{{Hydromorphological quality elements header}} | {{Hydromorphological quality elements header}} | ||
{{End table}} | {{End table}} | ||
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{{Additional Documents end}} | {{Additional Documents end}} | ||
{{Additional links and references header}} | {{Additional links and references header}} | ||
{{Additional links and references | |||
|Link=https://www.youtube.com/watch?v=biWRCJ0zYW0 | |||
|Description=Upper Witham River Prize Film 2024 | |||
}} | |||
{{Additional links and references footer}} | {{Additional links and references footer}} | ||
{{Supplementary Information}} | {{Supplementary Information}} | ||
{{Toggle content end}} | {{Toggle content end}} | ||
Latest revision as of 09:31, 24 May 2024
Project overview
| Status | In progress |
|---|---|
| Project web site | |
| Themes | Fisheries, Flood risk management, Habitat and biodiversity, Social benefits |
| Country | England |
| Main contact forename | David |
| Main contact surname | Hutchinson |
| Main contact user ID | |
| Contact organisation | Environment Agency |
| Contact organisation web site | http://Environment%20Agency |
| Partner organisations | East Mercia Rivers Trust, formerly Lincolnshire Rivers Trust, Wild Trout Trust, National Trust, Grantham Angling Association Fly Fishing Section, South Kesteven District Council, University of Lincoln. |
| This is a parent project encompassing the following projects |
Aubourn Rock Ramp and Habitat Works, Belton Floodplain Reconnection and River Restoration, Dysart Park, Grantham Habitat Improvement, Grantham Blue Green - Urban Reach, Little Ponton, Manthorpe Floodplain Reconnection, Papermill Weir Section in-channel restoration, River Witham Great Ponton, Stainby Road, Colsterworth, Syston and Barkston Restoration, Upper Cringle Floodplain Restoration Project, Upper River Witham : Easton, Westborough, Wyndham Park, Grantham |
Project summary
The Upper Witham has been subject to significant changes which have modified the river and its hydrological functioning. These legacy interventions have been damaging to habitat and with serious pollution incidents, climate change implications and invasive species threats, native species such as White Clawed Cray-fish and Brown Trout are at risk of local extinction. A ground water fed system has now also become far more reactive in response to an increase in storm intensity across the area.
Habitat improvement, rejuvenating a self-regulating functional active river system has been an aspiration for stakeholders working in the catchment for some time. Initial attempts at improving in-channel habitat from 2013 (EA, WTT and GAAFFs) used hinged trees and berms to narrow the river and scour pools. In the lower reaches, downstream of Grantham, this provided habitat in a system where it had previously been removed and was a good addition. Reviews of work did however indicate that this approach was not always having the desired effect; linked to very resistant clay bed and banks, poor gravel supply, and a lack of floodplain connectivity.
Lessons were learned and subsequent landowner and flood risk engagement took place. These were applied in the EA and NT’s Belton project which began in 2016 with imported gravels added at the time. This worked well and provided a blueprint for works in the nearby urban setting of Wyndham Park, Grantham (EA and SKDC in 2017). More urban projects in the town followed from the Rivers Trusts (Dysart Park 2020) and most notably the Blue Green corridor project led by SKDC with more gravels added, trees hinged, berms created, and wildflower and wetlands introduced widely along the river. Belton was revisited in 2023 where floodplain connectivity was increased through strategic floodplain lowering and reconnection using live and dead woody material as the driver for change.
The scale and ambition of individual projects increased with a more recent focus on larger scale projects connecting rivers with their floodplains more frequently. Manthorpe flood bank removal in 2020 (WTT and EA), Upper Cringle Brook ‘stage 8’ 2022 (EMRT), Grange Farm Stage 0 restoration (EA 2021) and Colsterworth (EMRT 2023) system reactivation, as well as innovative techniques such as smaller size gravel augmentation downstream of weirs (2023, WTT and GAAFFS at Papermill weir). Three large scale weir easement projects have also taken place at Aubourn (2016), Great Ponton (2015) and Easton (2014).
Monitoring surveys and results
We have learnt a great deal about lowland restoration and have applied this learning as the projects have progressed. Valuable feedback has come from revisiting project sites and undertaking objective reviews e.g 2018 Wild Trout Trust report . This is how we identified the importance of gravel and floodplain connectivity. We have long term ecological data for sites in the river that indicate that habitat works play a part in the continued improvement and prevention of determination of the ecology e.g Foston Ford fish surveys. Other sites like Easton Park show the limitations of some of the early in-channel techniques particular for fish populations although other factors like pollution incidents and low flow may be playing a role. Trout Redd surveys also provide good supporting data. Other monitoring techniques we have used include geomorphological surveys and drone topographical surveys. As the larger projects continue to evolve, our understanding of the impact they are having continues to develop, but it is clear following the storm events of winter 23/24 that we are undertaking projects that are both sustainable and are returning dynamic river processes to a lowland system.
Lessons learnt
To get maximum benefit from projects, in areas with less constraints, we needed to look wider than interventions focused just within the channel and consider the floodplain as well. Further learning for individual projects can be found in the project specific case studies.
Image gallery
|
Catchment and subcatchmentSelect a catchment/subcatchment
Catchment
Subcatchment
Other case studies in this subcatchment: Aubourn Rock Ramp and Habitat Works, Belton Floodplain Reconnection and River Restoration, Dysart Park, Grantham Habitat Improvement, Grantham Blue Green - Urban Reach, Little Ponton, Manthorpe Floodplain Reconnection, Papermill Weir Section in-channel restoration, River Witham Great Ponton, Stainby Road, Colsterworth, Syston and Barkston Restoration... further results
Site
Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
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