Case study:Goldrill Beck River Restoration
This case study is pending approval by a RiverWiki administrator.
Project overview
| Status | Complete |
|---|---|
| Project web site | |
| Themes | Flood risk management, Habitat and biodiversity, Hydromorphology, Monitoring, Social benefits, Water quality |
| Country | England |
| Main contact forename | Alice |
| Main contact surname | James |
| Main contact user ID | User:AliceJames |
| Contact organisation | The National Trust for Places of Historic Interest or Natural Beauty |
| Contact organisation web site | http://www.nationaltrust.org.uk/ |
| Partner organisations | Environment Agency, Natural England |
| Parent multi-site project | |
| This is a parent project encompassing the following projects |
No |
Project summary
Goldrill Beck runs from Brothers Water to Ullswater, in the Lake District, and is part of the River Eden and Tributaries SSSI. The beck was historically straightened, before the date of the earliest maps of the area, and subsequent years have seen further modifications including the addition of increasingly substantial revetments and large embankments. The channel was devoid of any features, and until recently, there was also a regular cycle of gravel removal. Stripped of its natural processes, the resulting channel was an exceptionally effective conveyor of water and sediment, moving large quantities of each rapidly downstream.
In 2015, Storm Desmond devastated communities across Cumbria. Breaking many meteorological records, the storm event resulted in 7,465 homes being flooded. Roads were closed in 107 locations, with 354.8km of highway damaged (Cumbria County Council 2018). A long section of the A591 was washed away, cutting the Lake District in half for over five months while the road was repaired. In Ullswater, the A592 is a similarly significant road through the valley, but Goldrill Beck ran adjacent to the road with it’s western bank forming the wall between road and river. The flood brought the fear that this vital transport link could suffer the same fate as the A591 in the next storm.
In 2018 the National Trust’s Riverlands project, part of a national programme of river and catchment restoration work, began working with the Trust’s agricultural tenant farmer, the Environment Agency and Natural England to develop an ambitious river restoration scheme. The aim was to protect the A592, deliver process-based restoration, enhance the SSSI condition, and improve floodplain ecology.
The restoration design was completed in 2019. Having considered several options, a decision was made to re-meander the river across the floodplain. The new course would follow the preferred course of the water as indicated by a direct rainfall model, which simulated surface-water flows over the floodplain based on its topography. This option was chosen as it would immediately remove the risk to the A592, as well as provide a course for the river through the improved floodplain, where there was concern about the potential for uncontrolled and ongoing silt releases into the SSSI from other options.
The final design included re-meandering the entire reach that abutted the A592, as well as adding bifurcations, ditch restoration, pond creation, a mixture of drain blocking and de-culverting, and encouraging the development of anastomosing channels through an existing wet woodland. A significant length of embankment was also removed downstream of the primary restoration reach, enabling the reconnection of the river and floodplain.
Construction took place in summer 2021, taking 12 weeks to complete. The river has now increased in length from 889m to 2,500m, and is fully connected to its floodplain. Across the site natural processes have been allowed to proceed without interruption. The change since the project was completed has been dramatic, and the dominance of natural processes in evident. One of the bifurcated channels has blocked and unblocked several times, and large gravel bars have formed. Eroding riverbanks are creating valuable river-cliff habitat, and large woody debris has arrived, lodging in the channel. The wet woodland is rapidly changing, forming new channels with fallen trees and vegetation pushing the water in different directions. Floodplain habitat is significantly wetter, with ephemeral and permanent ponds and an increasing variety of plant species. Over the course of two winters, 2,170m3 of sediment has been stored across the site; this material would once have been conveyed rapidly downstream and added to the flood risk for local communities. Data analysis of the flood attenuation performance of the scheme is ongoing, with data collected from two years pre- restoration and two years post-restoration. Initial results from a single storm event show a delay between up and downstream flood peaks of over an hour, although it’s expected that aggregated data from all the events across the monitoring period will show a more modest delay on average.
The area is grazed by cattle, the same herd as had previously grazed the site pre-restoration. They are supporting the breaking-up of the species-poor rush pasture, which is also being disrupted by regular inundation from the river and deposition of sediment. Finally, in January 2023, 16 Black Poplar Populus nigra ssp. betuifolia were planted on the floodplain. One of the rarest trees in Britain, its population has dwindled to an estimated 7,000 individuals across the country. The Black Poplars planted at Goldrill were propagated from a grove of 35 veteran trees in London, which had been saved by conservation specialist Jamie Simpson after genetic analysis confirmed this was most likely the only known surviving wild population left in the UK, and the only population with a 50:50 ratio of female and male specimens. Close of these individuals are the trees now standing on the floodplain at Goldrill.
Monitoring surveys and results
The results of four years of monitoring data from pressure transducers at the up and down stream extents of the restoration are being analysed. Results will be added here once available.
Lessons learnt
Image gallery
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Catchment and subcatchment
Site
Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
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