Case study:Arborfield nature like bypass and weirs project
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- 1 Project overview
- 2 Image gallery
- 3 Catchment and subcatchment
- 4 Site
- 5 Project background
- 6 Reasons for river restoration
- 7 Measures
- 8 Monitoring
- 9 Additional documents and videos
- 10 Additional links and references
- 11 Supplementary Information
|Project web site|
|Themes||Fisheries, Flood risk management, Habitat and biodiversity|
|Main contact forename||Dominic|
|Main contact surname||Martyn|
|Main contact user ID|
|Contact organisation||Environment Agency|
|Contact organisation web site||http://www.environment-agency.gov.uk|
|Parent multi-site project|
| This is a parent project
encompassing the following
In this reach, impassable flow control structures impounded the river by 1.4m, for over 4km upstream. WFD fisheries surveys determined moderate to poor ecological status upstream of the structures, with good ecological status downstream.
Project objectives to improve WFD status upstream of weir structures from 'moderate' to 'good', along with flood alleviation. Works involved lowering of 5 structures along an 800m section of river, construction of a 200m nature-like weir bypass channel to create free fish migration status, in addition to two backwaters created towards the end of the bypass channel and directly downstream of its exit; as well as creation of 80m of new riffle habitat for spawning.
After twenty years of work, a significant partnership project helping to deliver Water Framework Directive objectives has been completed on the River Loddon at Arborfield, near Reading.
The problem: Arborfield weirs were highlighted as the most significant barrier to fish migration in the Loddon catchment limiting natural habitat types upstream. Local access and flooding issues were raised.
The solution: Two hundred meters of complex channel and backwaters bypassing Arborfield weirs have been created. This will provide some 20km of free fish passage from the River Thames towards Basingstoke at certain times of year for a range of fish like sea trout, barbel and eels. The project delivers enhanced fish spawning and nursery grounds and restores impounded habitat.
The new river channel will help the Loddon towards meeting 'Good Ecological Status' required by the Water Framework Directive (WFD) and aims to be helpful as a case study for similar WFD-led projects around the country.
- Working with communities: anglers and local people shaped objectives and gave practical input; University of Reading and Cranfield University are helping with monitoring.
- Allow free fish passage to enable fish to complete lifecycles. We have seen fish entering the channel from top and bottom, confirming the bypass is passable for a variety of small fish.
- Improve Water Framework Directive status from moderate to good: create new fish spawning and nursery areas and monitor effects.
- Restore impounded habitat: lower weirs to restore flow and habitats. Chub have been observed spawning twice on restored riffles upstream since the weirs were lowered.
- Restore Biodiversity Action Plan habitat; construct wet feeds to key areas.
- Provide national case study: ‘before’ and ‘after’ studies to inform others.
- Improve site health and safety: better, safer access around site.
- Local flood risk: lower weirs have reduced breaching to adjacent land.
Works included: Thames Water weir lowering and repair work to four out of five structures - to lower upstream water levels and reduce overbank flow frequency.
Community Involvement - Presentations and meetings with local citizens. Volunteers involved in construction and future management of project.
Monitoring surveys and results
Over 1 hectare of nationally important wetland habitats will be restored - benefiting wildlife such as otters, kingfishers and dragonflies. A key feature of the 400k project was the successful partnership with Thames Water, the University of Reading, Farley Estate and Arborleigh Angling Club. Over 60 volunteer days were given
Catchment and subcatchment
Select a catchment/subcatchment
Cost for project phases
Reasons for river restoration
Hydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Additional documents and videos
Post-project ecological/hydromorphological monitoring assessments during 2011/12. Data should be available during 2012.