Groundwater situation report

Wessex ( and South Wiltshire) update 11 January 2016

Current situation

There is a flood warning in force for the South Winterbourne Valley; groundwater flood alerts are in force for Chase and the West of Dorset. Groundwater on Plain is rising but at present is below the flood alert level. The latest summary of the water situation in the south west, giving details of the rainfall, groundwater levels and river flows, can found on GOV.UK. Despite the extreme rainfall across the north of the country, we had 103% of the long term average. As with previous months it was wettest in the west of the patch and driest in the north eastern corner (Salisbury Plain). There have been some periods of significant rain at the beginning of January and this has lead to groundwater levels rising quite sharply. We are seeing all the prominent springs and winterbournes in the West of Dorset and flowing. In the West of Dorset, the level at the Kingston Russell borehole, on 11/01/2016, was 116.66 metres above sea level (mAOD). This is just above the flood warning Level. Groundwater levels at Kingston Russell borehole are ranked as "above normal" for this time of year.

www.gov.uk/environment-agency

On Cranborne Chase, the groundwater level at the West Woodyates borehole is 101.38 mAOD. The highest ever recorded level at the borehole was in January 2014 when it reached 109mAOD. Groundwater levels are ranked currently as "normal".

On Salisbury Plain, the current groundwater level in the Tilshead borehole is 86.66mAOD. This is an increase of around 4 metres. At this time last year the level was 92.1 mAOD. The groundwater level in this indicator borehole is ranked as "below normal".

www.gov.uk/environment-agency

Current forecast risk of groundwater flooding

Our most recent modelling of groundwater levels shows that groundwater levels will continue to rise during the next week. The flood warning for the South Winterbourne will stay in force and further flood warnings may be issued for the North Winterbourne and the Piddle Valley. Rainfall totals for the coming week (11/01/2016) are relatively low and this may lead to a slowdown in the rate of rise. Springs will continue to break and low lying roads and septic tanks could be affected. Householders should ensure any flood protection products, such as pumps, are working and in place. Our most recent forecast for Salisbury Plain shows a low risk of groundwater levels meeting flood alert. More details of the predictions can be found in the monthly Water Situation Report for . The new groundwater flood warning service

For several years we have been able to issue groundwater flood alerts across the area. The 3 alert areas are the West of Dorset, Cranborne Chase and Salisbury Plain. A flood alert warns that flooding is possible; be prepared. Following the groundwater flooding in 2013/2014 we have analysed our records and have produced 22 community-based flood warning areas. These cover smaller, more defined areas than the flood alerts. A flood warning is used to warn people that flooding is expected; immediate action is required. To find out if you are at risk and to register to receive these flood alerts and flood warnings for groundwater, call Floodline on 0345 988 118 (24 hour service) or go online at www.gov.uk/environment- agency

The new warning areas are: The Bourne Valley • The Collingbournes, including Aughton, Collingbourne Kingston and Collingbourne Ducis • North of the A303, including Tidworth and Shipton Bellinger • Winterbornes and Salisbury, including Cholderton, Newton Tony, Allington, Idmiston, Porton, Winterborne Gunner, Winterborne Earls and Laverstock

River Till and Chitterne • The Till, including Tilshead, Orcheston, Shrewton, Winterborne Stoke, Berwick St James and Stapleford • The Chitterne, including Chitterne, Codford St Peter and Codford St Mary

The Ebble • Ebble Valley, including Berwick St John, Ebbesbourne Wake, Bowerchalke, Broad Chalke, Stoke Farthing, Bishopstone, Stratford Toney, Coombe Bissett, Homington, Odstock and Nunton • The Cranborne Chase in West Hampshire, including Martin, Damerham, Sandleheath, Rockbourne, Whitsbury, Fordingbridge and Breamore

www.gov.uk/environment-agency

Vale of Allen • The Allen, including Sixpenny Handley, Wimborne St Giles, Witchampton and parts of Wimborne • The Crane, including Pentridge, Cranborne and Edmondsham • The Crichel, including , and • The , including Tollard Royal, Farnham, Minchington, Cashmoor, Gussage St Michael and • The Brook at Pimperne • The Tarrants, including Stubhampton, , , , , , and • The Iwerne, including , , , Shroton and

North Winterborne • The North Winterborne, south of the A354, including , Kingston, Zelston and Newton Peveril • The North Winterborne, north of the A354, including , , Houghton, Clenston, Whatcombe and Whitechurch

Frome and Piddle • , including Alton Pancras, Piddletrenthide, White Lackington, Piddlehinton, Puddletown and Athelhampton • Bere Stream, including Hilton, and • Cerne, including Minterne Magna, Minton Parva, Cerne Abbas, Nether Cerne, , Forston and Charminster • Devils Brook, including Ansty, , and Dewlish • Hooke, including , Hooke and • Sydling, including Up Sydling and Sydling Nicholas

South Winterborne Valley • South Winterborne, including Kingston Russell, Winterborne Abbas, Steepleton, Martinstown, W. Monkton, W. Herringston, W. Came and West Stafford Actions and advice

• Think and prepare now for what you'll do if flooding occurs where you live, don't wait until flooding happens • If you have a personal flood plan you should put it into action • Move valuables from basements and cellars • If you have a pump ensure it is serviced and working effectively • Keep drains and gullies around your property free of debris • You may need to improve surface water drainage and/or install and assess sump pumping arrangements • Visit the Environment Agency website for local water levels and flooding information www.gov.uk/environment-agency • Many of the groundwater boreholes are being added to the website Gauge Map. This shows up to date river and groundwater levels

www.gov.uk/environment-agency

• If you own part of the river bank you should keep the banks and bed of the river clear of debris

We are encouraging parishes at risk to develop a Community Flood Plan, identifying local issues and working with the different agencies to prepare and respond to flooding should it occur later in the year.

Next update

The next scheduled update will be on 20/01/2016, unless the situation changes.

Further information

To see the current status of the flood alert for Salisbury Plain follow the link: Groundwater on Salisbury Plain

To see the current status of the flood alert for Cranborne Chase follow the link: Groundwater on Cranborne Chase

To see the current status of the flood alert for the West of Dorset follow the link: Groundwater in

Contacts

If you would like any further information on groundwater levels in the area please contact us by emailing [email protected] . Please use this email to report incidences of groundwater flooding.

Alternatively ring Floodline 0345 988 118 or the National Incident Hotline on 0800 80 70 60.

www.gov.uk/environment-agency