SRA End of Year Report 2016-17: Dredging and river management – Workstream 1
Cannington Flood Alleviation Scheme
In the last decade, 40 – 50 properties in Cannington have flooded several times. The A39 has been rendered impassable, causing serious problems for emergency vehicles, Hinkley Point and local services. An SRA contribution of £300,000 enabled a £4m scheme to go ahead, led by the Environment Agency in partnership with EDF, Cannington Parish Council, Wessex Water and Somerset County Council. Being achieved: A relief channel was dug to divert flood water away from Cannington and better protect 200 homes. Final completion was pushed back to early summer 2017 by delays in gas main diversion.
Pumping Station Repairs and Improvements
SRA-funded works increase the resilience and security of permanent pumping stations and help temporary pumps to be accommodated and operated. Environment Agency budgets do not allow for this degree of extra maintenance and improvement.
Achieved: West Sedgemoor PS (windows replaced), Stockmoor PS (improvements for pump deployment and monitoring), Midelney PS (roof-fixing, removing asbestos, repairing concrete slab on which building sits), Westover PS (sheet-piling to stop water leaking from the Parrett under the station to Huish Level moor, from where it requires pumping out).
Being achieved: Roof repairs and inlet channel works due in 2017 at Long Load PS (late Spring), Saltmoor PS (early Summer, dovetailed with pump extraction and replacement), North Drain PS (Autumn).
Main River Asset Improvements
Achieved: 1) Rode Bridge, near Frome, is a Scheduled Ancient Monument that was vulnerable to being damaged when the River Frome rose high during times of flood and water could not smoothly pass through its two main middle arches. Side arches were partially blocked with earth, vegetation and debris. Works improved flows through the bridge, to a) create more flood capacity, b) prevent flood waters backing up in the Frome’s flood plain, and c) benefit the adjoining inn The Mill at Rode, recently refurbished at a cost of £400,000 by owners Butcombe Brewery. They joined in as partners to this scheme, paying for further improvements. The scheme was designed and delivered for the SRA by the Environment Agency with contractors Land & Water.
Achieved: 2) Orchardleigh / Spring Gardens: An area of complex channels, with a long history of flooding problems, close to where the Mells River joins the Frome. More flood capacity created by removing dead and fallen trees that were obstructing the flow of the Mells River through Orchardleigh, near Brookover, and clearing the old Mill Race in Spring Gardens. The scheme was designed and delivered for the SRA by the Environment Agency, using five Somerset men from Lawton Forestry sub-contracting for Ground Control. (Below: Mike Richards felling part of a tree).
Achieved: 3) Mis Brook, between Beer Wall and Langport: three culverts installed to improve access for Environment Agency maintenance works.
Being achieved: Huntworth pump – new electric canister pump selected, and supporting hydrometry installation designed (to trigger the pump). Infrastructure agreement reached with Western Power Distribution. Pump due in place for use by November 2017.
Not yet achieved: Huntworth Brook de-silting postponed for environmental reasons; work now scheduled for Autumn 2017.
Cripps River, Mark Yeo, Hixham
The Environment Agency, for the SRA, proposed to follow up on three pioneer dredges in 2015.
Achieved: The banks of the Cripps were re-seeded and temporary fences removed. Another 1km of Hixham Rhyne was dredged, downstream of the 2.2km done previously.
Not yet achieved: Environmental considerations meant that work on the Mark Yeo near Rooks Bridge is now scheduled for Autumn 2017.
Brue tree work
Improving flow capacity between Hackness and North Drain Pumping Station Scheme by removing fallen trees and pruning obstructive trees. Not yet achieved: Works being planned for September 2017, but will depend on obtaining an Environmental Permit which is likely to require reference to the Environment Agency’s River Brue hydraulic model (being reviewed as part of the dredging strategy).
West Sedgemoor and Aller Moor
Previous funding regimes restricted maintenance on these moors, mostly to every other year, resulting in reduced channel flow capacity and land recovering more slowly from flooding. Achieved: Parrett IDB weed clearance and sediment removal now yearly, with around 37,500m of additional channel maintenance.
Isle Brewers bank repairs
A bank colonised by badgers near Isle Brewers is an important part of the village’s flood defences. If badgers dug right through, flood water could surge through and destroy the bank. Restoring it would cost a lot of money. The Environment Agency’s existing budget allows for routine maintenance work at Isle Brewers, but not for tackling badgers. Achieved: The SRA funded extra work to protect local people and properties. The Environment Agency, on behalf the SRA, installed steel sheet piles to stop badgers digging through the bank. No badgers were moved or harmed in the work, which was carried out by a specialist contractor under licence from Natural England. Badgers are a protected species.
West Somerset Streams
Few places in Somerset are being targeted with such a range and number of small-scale improvements as Carhampton. Achieved: The SRA funded the clearance of a heavily-overgrown channel, on Crown Estate land, from the junk shop down towards the village recreation field. This improved the channel’s capacity for conveying water, cutting flood risk in the village and along the A39, benefitting local people, businesses, and visitors going to and from Dunster, Minehead and Exmoor. The Environment Agency delivered the work, supported by Somerset County Council, with – as also at Minehead – Quantock & Exmoor Tree Care sub-contracting for Ground Control. Below: Local men Wes Hopwood and Rob Bruce at work for the SRA in Carhampton.
About a third of the properties in Minehead and nearly all of the town’s businesses are at high risk of surface water flooding and, in the past, problems have occurred because of under-capacity in channels and structures being blocked. Most of Minehead lies within the floodplain of the Bratton Stream and its tributaries. Being achieved: Improvements along the Bratton Stream in Parks Walk. Invasive species were removed, and trees and bushes trimmed by hand, to enhance the stream’s capacity to carry water, while maintaining its appeal as a popular feature of Minehead’s second-biggest park. The Environment Agency delivered the work for the SRA. It was paused in early Spring 2017 to allow for fish migrating.
Maintaining Resilience of Wet Grassland
A plan to improve, replace or remove almost 240 water-level control structures and bring extra benefits to farming and wildlife for the next 20-30 years in key parts of the floodplains upstream of Langport.
Not yet achieved: Identifying a lead body with sufficient resource to scope and agree the project initially hampered progress. Five landowner consultations complete. IDB/ Natural England site inspection complete (with regard to water levels). Natural England ‘bird use’ survey undertaken.
After public consultation in 2015, the SRA Board decided to commission further work in Chadmead and Moorland to see if greater consensus could be reached about possibilities that local people could choose to support or reject, given more information. Being achieved: As there was more initial consensus in Chadmead, a draft technical report has been prepared by the Parrett IDB, suggesting three possible design options for Chadmead. Discussions are planned in partnership with local people later in 2017, so they can decide together what (if any) further progress is desirable.
Step change in encouraging and enforcing riparian work
In the wake of the floods of 2013-14, it was widely felt in Somerset that problems were exacerbated because too few riparian owners knew and carried out their responsibilities, particularly for maintenance. There was a need to be more pro-active. Not yet achieved: The job of Riparian Enabling and Enforcement Officer has been offered as a secondment to a Somerset County Council applicant, and the role is due to be taken up in Summer 2017. The Officer will work with all SRA partners, backed up by communications activity that will seek to raise awareness of riparian owners’ responsibilities.
South Somerset Enhanced Maintenance
SRA funding enables smaller schemes that deal with local issues in a pro-active way that makes flood alleviation schemes work with extra effectiveness. Achieved: Enhanced maintenance and safety improvements completed at North Perrott by South Somerset District Council’s Streetscene team: repair works to improve flows at Portfield Lane, Langport (in Curry Rivel parish).
Sedgemoor District Council flood relief and drainage assets
Additional SRA funding gives Sedgemoor DC greater capacity to undertake works that deal with issues before they become problems and to put in enhancements, such as telemetry, that make flood defence schemes and infrastructure more efficient.
Achieved: Extra maintenance in the stream next to North Petherton Primary School (repairing the weir structure, replacing head and retaining walls, improving access) and near Greinton (culvert repairs to prevent more costly and disruptive works later).
Being achieved: Telemetry equipment due to be installed by June 2017 at Blake Gardens, Bridgwater and Bays Pond, Cheddar. Real-time data will help flow regulation and barrier deployment.