https://restorerivers.eu/wiki/api.php?action=feedcontributions&feedformat=atom&user=Huw+Jones 2026-04-11T15:54:54Z User contributions MediaWiki 1.39.7 https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42918 2018-11-28T17:15:22Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Case study image<br /> |File name=Gravelreintroduction.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSection.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSectionbefore.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016SectionBeforedownstream.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016SectionAfterdownstream.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Case study documents<br /> |File name=Phase 5 works summary.pdf<br /> |Description=2015 works completed<br /> }}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:2016SectionAfterdownstream.JPG&diff=42917 2018-11-28T17:15:03Z

<p>Huw Jones: 2016 section, looking downstream, after restoration</p> <hr /> <div>2016 section, looking downstream, after restoration</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:2016SectionBeforedownstream.JPG&diff=42916 2018-11-28T17:13:24Z

<p>Huw Jones: Section restored in 2016 - looking downstream, before restoration</p> <hr /> <div>Section restored in 2016 - looking downstream, before restoration</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42915 2018-11-28T17:09:20Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Case study image<br /> |File name=Gravelreintroduction.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSection.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSectionbefore.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Case study documents<br /> |File name=Phase 5 works summary.pdf<br /> |Description=2015 works completed<br /> }}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:2016RestoredSectionbefore.JPG&diff=42914 2018-11-28T17:09:08Z

<p>Huw Jones: 2016 Work section before boulder replacement</p> <hr /> <div>2016 Work section before boulder replacement</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42913 2018-11-28T16:56:25Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Case study image<br /> |File name=Gravelreintroduction.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSection.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Case study documents<br /> |File name=Phase 5 works summary.pdf<br /> |Description=2015 works completed<br /> }}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42912 2018-11-28T16:55:48Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Case study image<br /> |File name=Gravelreintroduction.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSection.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Case study documents<br /> |File name=Phase 5 works summary.pdf<br /> }}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Phase_5_works_summary.pdf&diff=42911 2018-11-28T16:55:41Z

<p>Huw Jones: Phase 5 works summary (2015)</p> <hr /> <div>Phase 5 works summary (2015)</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42910 2018-11-28T13:07:24Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Case study image<br /> |File name=Gravelreintroduction.JPG<br /> }}<br /> {{Case study image<br /> |File name=2016RestoredSection.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:2016RestoredSection.JPG&diff=42909 2018-11-28T13:07:07Z

<p>Huw Jones: Restored section from 2016 where boulders were replaced and clean gravel reintroduced to the river.</p> <hr /> <div>Restored section from 2016 where boulders were replaced and clean gravel reintroduced to the river.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Gravelreintroduction.JPG&diff=42908 2018-11-28T13:06:09Z

<p>Huw Jones: Clean gravel being gradually introduced into the river using an improvised visqueen chute arrangement (Upper River Section 2015).</p> <hr /> <div>Clean gravel being gradually introduced into the river using an improvised visqueen chute arrangement (Upper River Section 2015).</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42906 2018-11-27T20:09:16Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Case study image<br /> |File name=Restoredsection2006.jpg<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Restoredsection2006.jpg&diff=42905 2018-11-27T20:09:02Z

<p>Huw Jones: Restored section. Note significantly raised river bed level compared with image showing the same section post dredging.</p> <hr /> <div>Restored section. Note significantly raised river bed level compared with image showing the same section post dredging.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42904 2018-11-27T19:36:21Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1995-6. Investigation work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> Due to the sensitive species present in this river, a spread out one step at a time approach to restoration has been appropriate.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42903 2018-11-27T19:32:29Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy in and suitable catchment management is essential, and there is a good uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42902 2018-11-27T19:29:55Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. In the Afon Ddu, this has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42901 2018-11-27T19:28:43Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> This river is an UK Biodiversity Plan Priority River for Margaritifera margaritifera, along with two other Welsh rivers.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42900 2018-11-27T19:26:59Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrier.JPG<br /> }}<br /> {{Case study image<br /> |File name=Partialbarrierameliorated.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Partialbarrierameliorated.JPG&diff=42899 2018-11-27T19:26:48Z

<p>Huw Jones: Partial barrier following amelioration work.</p> <hr /> <div>Partial barrier following amelioration work.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Partialbarrier.JPG&diff=42898 2018-11-27T19:26:04Z

<p>Huw Jones: Partial barrier to salmonid migration before amelioration.</p> <hr /> <div>Partial barrier to salmonid migration before amelioration.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42897 2018-11-27T19:17:40Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-machineworking.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-before.jpg<br /> }}<br /> {{Case study image<br /> |File name=Sept2005-after.jpg<br /> }}<br /> {{Case study image<br /> |File name=2009Restored section.JPG<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:2009Restored_section.JPG&diff=42896 2018-11-27T19:17:29Z

<p>Huw Jones: Image of the restored section from 2009. Note absence of finer substrate which tends to be associated with suitable Margaritifera margaritifera habitat, and is indicative of gravel starvation in the Afon Ddu.</p> <hr /> <div>Image of the restored section from 2009. Note absence of finer substrate which tends to be associated with suitable Margaritifera margaritifera habitat, and is indicative of gravel starvation in the Afon Ddu.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Sept2005-after.jpg&diff=42895 2018-11-27T19:12:15Z

<p>Huw Jones: Image showing section with boulders and sediment placed in channel</p> <hr /> <div>Image showing section with boulders and sediment placed in channel</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Sept2005-before.jpg&diff=42894 2018-11-27T19:11:17Z

<p>Huw Jones: Damaged section in 2005 before boulder and sediment replacement</p> <hr /> <div>Damaged section in 2005 before boulder and sediment replacement</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Sept2005-machineworking.jpg&diff=42893 2018-11-27T19:08:52Z

<p>Huw Jones: Phase 1 restoration from September 2005</p> <hr /> <div>Phase 1 restoration from September 2005</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42892 2018-11-27T19:05:25Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Case study image<br /> |File name=1996damagedsection.jpg<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:1996damagedsection.jpg&diff=42891 2018-11-27T19:05:16Z

<p>Huw Jones: Further image of the damage from 1996</p> <hr /> <div>Further image of the damage from 1996</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42890 2018-11-27T19:03:10Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Case study image<br /> |File name=1996dredgingdamage.jpg<br /> }}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:1996dredgingdamage.jpg&diff=42889 2018-11-27T19:03:02Z

<p>Huw Jones: Image of the river from 1996 showing damage caused by dredging operations.</p> <hr /> <div>Image of the river from 1996 showing damage caused by dredging operations.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:1996_Post_Dredging.jpg&diff=42888 2018-11-27T18:59:18Z

<p>Huw Jones: Image of the river in 1996 showing damage following dredging operations. (National River Authority image).</p> <hr /> <div>Image of the river in 1996 showing damage following dredging operations. (National River Authority image).</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42887 2018-11-27T17:35:00Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site<br /> |Name=Afon &amp; Llyn Du<br /> |WFD water body code=GB110065053690<br /> |WFD water body name=Cwmystradllyn<br /> |Pre-project morphology=Over deepened,<br /> |Reference morphology=Pool-riffle,<br /> |Desired post project morphology=Pool-riffle<br /> |Heavily modified water body=No<br /> |Site designation=UK - Site of Special Scientific Interest<br /> |Protected species present=Yes<br /> |Invasive species present=No<br /> |Species=Freshwater pearl mussel (Margaritifera margaritifera),<br /> |Dominant hydrology=Perennial<br /> |Dominant substrate=Gravel,<br /> |River corridor land use=Non-intensive agriculture (grazing)<br /> |Average bankfull channel width category=Less than 2 m<br /> |Average bankfull channel depth category=Less than 0.5 m<br /> |Mean discharge category=Less than 0.1 m³/s<br /> }}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42886 2018-11-27T17:25:08Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site}}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures<br /> |Bank and bed modifications measure=Boulder restoration, Addition of substrate and in channel features,<br /> |Floodplain / River corridor=Fencing of riparian zone,<br /> |Planform / Channel pattern=Creation of fish passes,<br /> |Other technical measure=Deculverting<br /> |Management interventions=Agricultural business changed its way of working,<br /> }}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42885 2018-11-27T17:23:07Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site}}<br /> {{Project background<br /> |Project started=2005/06/01<br /> }}<br /> {{Motivations}}<br /> {{Measures}}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42884 2018-11-27T17:18:34Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=This river was badly damaged by dredging / drainage operations in 1996/7. This work led to the discovery of a previously unknown population of Margaritifera margaritifera - the population was badly damaged by this work.<br /> Work to restore some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The bulk of this work concentrated on fencing out the river to reduce livestock access, but a short section of the most damaged section was restored in 2006. <br /> The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further work has been carried out with the aim of restoring in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005 by the partner organisations.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site}}<br /> {{Project background}}<br /> {{Motivations}}<br /> {{Measures}}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42883 2018-11-27T17:07:13Z

<p>Huw Jones: </p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Status=In progress<br /> |Themes=Fisheries, Habitat and biodiversity, Hydromorphology, Land use management - agriculture, Monitoring<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Partner organisations=Snowdonia National Park Authority, Welsh Government<br /> |Multi-site=No<br /> |Project picture=Restoration2016.JPG<br /> |Picture description=Restoration of the river<br /> |Project summary=Restoration of some sections of the Afon Ddu has been carried out by legacy Environment Agency Wales and Countryside Council for Wales and partner organisation Snowdonia National Park Authority since 2005. The river was designated as a pearl mussel Site of Special Scientific Interest in 2010/11.<br /> Since the formation of Natural Resources Wales, further extensive work has been carried out to restore in channel geomorphology, through the replacement of boulders and gravel seeding with an objective of improving the habitat for salmonids and Margaritifera margaritifera.<br /> <br /> The small catchment size means that close co-operation with landowners is likely to be more effective than in larger, dispersed, catchments in terms of achieving water quality objectives.<br /> <br /> Approx. £90,000 has been spent on fencing and habitat works on this river since 2005.<br /> |Monitoring surveys and results=Long term monitoring of Margaritifera margaritifera numbers in this river indicate a continuing decline in adult numbers, in common with other Welsh rivers. This has been mostly linked to unsuitable river habitat, both due to physical modifications and some issues with water quality. <br /> Monitoring of the success of the restoration work will in future be linked to NRWs use of the Redox potential measuring technique to determine the quality and cleanliness of the interstitial gravel which the juvenile stage of Margaritifera margaritifera rely upon. Monitoring indicates that the encystment stage of the Margaritifera margaritifera is occurring normally in this river, and that juvenile salmonid host numbers are good.<br /> |Lessons learn=Landowner buy and suitable catchment management is essential, and there is a high uptake of the Welsh Government's Glasdir Agri-Environment scheme in this small catchment.<br /> Successful captive rearing of juvenile mussels at the NRW Aquaculture Unit at Cynrig is considered to be an important future development to secure the future of the species.<br /> |Project title=Ddu Restoration Project<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site}}<br /> {{Project background}}<br /> {{Motivations}}<br /> {{Measures}}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=File:Restoration2016.JPG&diff=42882 2018-11-27T16:43:10Z

<p>Huw Jones: Restoration by replacing boulders and gravel reintroduction of the mid section of the Afon Ddu through work funded by Natural Resources Wales in co-operation with the landowner.</p> <hr /> <div>Restoration by replacing boulders and gravel reintroduction of the mid section of the Afon Ddu through work funded by Natural Resources Wales in co-operation with the landowner.</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=Case_study:Ddu_Restoration_Project&diff=42881 2018-11-27T16:35:07Z

<p>Huw Jones: Created page with &quot;{{Case study status |Approval status=Draft }} {{Location |Location=52.96024856884791, -4.141320961354495 }} {{Project overview |Project title=Ddu Restoration Project |Status=I...&quot;</p> <hr /> <div>{{Case study status<br /> |Approval status=Draft<br /> }}<br /> {{Location<br /> |Location=52.96024856884791, -4.141320961354495<br /> }}<br /> {{Project overview<br /> |Project title=Ddu Restoration Project<br /> |Status=In progress<br /> |Themes=Flood risk management, Hydropower, Land use management - agriculture, Land use management - forestry<br /> |Country=Wales<br /> |Main contact forename=Huw<br /> |Main contact surname=Jones<br /> |Main contact id=Huw Jones<br /> |Contact organisation=Natural Resources Wales<br /> |Contact organisation url=naturalresources.wales/<br /> |Multi-site=No<br /> }}<br /> {{Image gallery}}<br /> {{Image gallery end}}<br /> {{Toggle button}}<br /> {{Toggle content start}}<br /> {{Case study subcatchment}}<br /> {{Site}}<br /> {{Project background}}<br /> {{Motivations}}<br /> {{Measures}}<br /> {{Hydromorphological quality elements header}}<br /> {{End table}}<br /> {{Biological quality elements header}}<br /> {{End table}}<br /> {{Physico-chemical quality elements header}}<br /> {{End table}}<br /> {{Other responses header}}<br /> {{End table}}<br /> {{Monitoring documents}}<br /> {{Monitoring documents end}}<br /> {{Additional Documents}}<br /> {{Additional Documents end}}<br /> {{Additional links and references header}}<br /> {{Additional links and references footer}}<br /> {{Supplementary Information}}<br /> {{Toggle content end}}</div>

Huw Jones https://restorerivers.eu/wiki/index.php?title=User:Huw_Jones&diff=42880 2018-11-27T16:31:58Z

<p>Huw Jones: </p> <hr /> <div>{{User page<br /> |realName=Huw Jones<br /> |Hide email link=No<br /> |name=Huw Jones<br /> }}<br /> I work for Natural Resources Wales (Cyfoeth Naturiol Cymru) as a Natural Resources Management Team Leader covering North Gwynedd &amp; Anglesey.</div>

Huw Jones