W4: Resilient Infrastructure 2018-19 – Additional Maintenance
This is the Additional Maintenance section of the SRA Annual Report 2018-19, part of W4: Resilient Infrastructure.
De-silting of structures, gully-emptying, drain jetting and targeted edge of road clearing were all delivered countywide for the SRA by Somerset County Council.
In areas covered by Internal Drainage Boards, an ongoing programme of remedial works to culverts is being led for the SRA by Somerset Drainage Boards Consortium.
Somerset County Council’s Highways Department empties gullies in areas most susceptible to flooding once a year. The SRA funded an additional six-month round for 15,043 of the highest-risk gullies countywide; far too many to list individually! The aim is to keep roads open, make them safer, preserve access for communities, and safeguard properties from flooding.
134 places benefitted in 2018-19; in Mendip 25, Sedgemoor 23, South Somerset 33, Taunton Deane 25, West Somerset 28.
Under existing budgets, Somerset County Council’s Highways Dept can only afford to jet drains when a bad blockage has occurred. SRA funding allows for earlier preventative maintenance at locations known to suffer problems with flooding, because they feature on annual gully-emptying rounds. Final selections are made using local knowledge and professional judgement.
Countywide targeted edge of road clearing
906 extra tonnes of debris were cleared from 32.44 miles of road edgeways at 22 places, to stop structures such as drains and gullies getting clogged. Roadsides in rural areas highly susceptible to flooding were swept after trees began to shed their leaves. This work is delivered for the SRA by Somerset County Council’s Highways Dept; it is an extra activity for Somerset because the county council does no other sweeping. The aim of this SRA-funded action is to reduce flood risks by stopping detritus entering and blocking drainage systems. Local knowledge and professional judgement are used in choosing sites and (where possible) road-edge clearing is integrated with other preventative maintenance activities such as extra gully-emptying.
- Ashwick, A37 Old Frome Rd – Underhill
- Binegar, A37 Underhill – Marchants Hill
- Cranmore (x2), A361 East Cranmore A361 and A361 Slait Hill – Haygrove
- Kilmersdon, B3139 Kilmersdon Hill
- Spaxton, Merridge Hill
- Bruton, B3081 Dropping Lane
- Cudworth, Cudworth Hill
- Lopen, Lopen Lane
- Montacute, Hollow Lane & Townsend
- Tatworth & Forton, B3162 Forton Road & Horn Moor Road
- Winsham, Whatley Lane
North Curry/Fivehead, Langport Rd
Wiveliscombe (x2), Hartswell, Langford Budville Road, Pyncombe Lane, South Street
- Nettlecombe (x2), Clitsome Lane, Slade Lane
- Old Cleeve (x2), Battallers Lane – Roadwater, Lodge Rocks
De-silting of structures
Works were completed at seven locations. The biggest scheme was around Blake Bridge in Bridgwater town centre. This job was delivered for the SRA by Somerset County Council’s Highways Dept using contractors Crestmoor Construction and several sub-contractors.
The two main aims were to increase the River Parrett’s ability to flow under the bridge, and to safeguard the bridge itself, as serious pressures were being exerted on its arches by very large build- ups of thick, heavy silt. Methods used included high-pressure jetting of silt on the banks and some water injection dredging from a vessel on the river.
Other locations where structures were de- silted were:
- Doulting Hill culvert, A361, between the Charlton House Hotel and Doulting Hill, tributary of River Sheppey
- Fosse Combe Culvert, between Spargrove and Albion’s Vale, River Alham
- Jordan’s South, bridge north of Horton Cross near Ilminster, tributary of River Isle
- Harpford Bridge, between Holywell Lake and Langford Budville, Tone catchment
- West Hatch Culvert, near Griffin Lane-West Hatch Lane junction, Parrett catchment
- Ford Bridge, A398 west of Timberscombe, River Avill
Culvert inspections and remedial works in IDB areas
Works have included de-silting, vegetation clearance, high-pressure water jetting and structural repairs. The main aims have been to improve the conveyance of water and to help prevent disruption to residents and road users.
One high-priority site was at Nythe, where a culvert was in a very bad state, with short sections of pipe disconnected and wonky. This increased the danger of water backing up and flooding the road. Also, a hole had appeared in the edge of the road and the ground was collapsing. This dangerously crumbling culvert was repaired at the end of March 2019, so that water could drain through under Nythe Road and traffic could keep flowing north of Langport between High Ham and Pedwell. Somerset Drainage Boards Consortium delivered the scheme for the SRA, using local contractors Bernard Perry. The job was completed ahead of schedule.