This is the Environment Agency's latest Newsletter.
Hampshire Area Groundwater Newsletter
10th January 2003
THE PRESENT SITUATION & OUTLOOK
The last week has been dry and the total rainfall for January so far is around 20mm. At Otterbourne, the total rainfall between October and December 2002 was 503mm and the annual total was 1114mm. These figures are almost identical to the rainfall measured at Otterbourne in 2000. In over 100 years of records at Otterbourne this is the second wettest October to December period with 1929 being the wettest. It is hard to believe that we have again experienced such heavy rainfall in the winter and this has been the cause of the current high groundwater levels.
We are aware of around 70 properties suffering from cellar flooding and about 15 properties have been reported with internal ground floor flooding. Numerous communities have field and road flooding and there are problems with sewers reported throughout the Area.
Groundwater levels are now peaking at the head of many valleys. Although groundwater levels are difficult to predict, we anticipate that levels in the upper valleys such as Vernham Dean may peak in the next 3 to 7 days. Levels further down the valleys in areas such as Upton, Hursley, Finchdean and Hambledon will take longer to peak and may not start to fall for at least 7 –14 days. Cellar flooding is expected to remain in many villages for several weeks. All estimates of duration of flooding given in this report are best estimates and are only appropriate if there is no further rain.
The current forecast suggests that there may be light rain early next week with unsettled conditions later in the week. If there is significant rainfall, groundwater levels will rise further.
NORTH EAST HAMPSHIRE & ITCHEN VALLEY ( Telemetry Borehole : Preston Candover)
Groundwater levels are still rising at Preston Candover although the rate of rise has reduced. Levels are expected to remain high for several weeks. Cellar flooding is expected in Preston Candover. Groundwater Levels are high but have started to fall in Bishops Sutton and Old Alresford.
The source of the River Test has risen beyond Ashe Park and groundwater flooding has been reported in Deane. Groundwater levels are expected to continue rising in Deane.
NORTH WEST HAMPSHIRE ( Telemetry Borehole : Clanville Gate )
Groundwater levels in North West Hampshire are now higher than the highest levels seen during the flooding in 2000/01. Levels are stable at Clanville and Appleshaw but are rising slightly in Hatherden. Levels are expected to remain high for several weeks in Hatherden, Penton Mewsey and Appleshaw. Flows in Appleshaw were measured as 330 litres per second on January 8th. The Pilhill Brook is rising near Shoddesden. Groundwater levels are high in Kimpton but have fallen slightly.
Flows are high in the Bourne Rivulet and groundwater levels have risen dramatically in Vernham Dean. Flows at Upton were recorded as 850 litres per second on 8th January. Several properties are flooded in Upton and there is cellar flooding and the risk of ground floor flooding for some properties in Vernham Dean. If there is no further rain, groundwater levels are likely to continue rising and could peak in Vernham Dean in the next week. Flows through Upton will start to fall after levels have peaked at Vernham Dean although water levels at Upton and in the Bourne valley will remain high for several weeks.
WEST HAMPSHIRE/WILTSHIRE ( Telemetry Borehole : Lopcombe Corner )
There is extensive road and field flooding in the valley around Pitton. Groundwater levels are also high at West Tytherley and in the Wallop valley. Levels are peaking at Lopcombe Corner but flooding is expected to remain in the area for at least 2 –3 weeks.
CENTRAL HAMPSHIRE ( Telemetry Borehole : West Meon Hut)
Water is now flowing from above Bramdean and one property is flooded internally. River flows are also high in Cheriton and groundwater flooding has been reported in one house. Groundwater levels at West Meon Hut are peaking but groundwater levels will remain high in Bramdean for several weeks.
Groundwater flooding is occurring in Upham, Owslebury, Hensting Lane and Dean near Bishops Waltham. Groundwater levels have peaked at the head of the Hensting Lane spring and levels in the area are expected to start to fall in the coming week. Drainage works have improved the situation in Twyford and groundwater levels are expected to fall over the coming week.
Levels have risen quickly at Harestock Corner. External flooding is occurring in Headbourne Worthy and external flooding and sewer problems have been reported in Littleton. Groundwater levels are high in Winchester.
Groundwater levels at Sutton Scotney, Stoke Charity and Wonston are now likely to be falling.
Groundwater levels are high in Kings Somborne and levels at the recreation ground are only 0.2m below ground. There is extensive road flooding in the Somborne Valley. Cellar flooding is occurring at Hursley and levels are expected to continue rising for at least the next 5 – 10 days.
EAST HAMPSHIRE ( Telemetry Borehole : Broadhalfpenny Down)
Groundwater flooding is occurring in Soberton and Meonstoke but levels are now falling.
Groundwater levels peaked at Broadhalfpenny Down just below 75m AOD and have been steadily falling since January 5th. Levels within Hambledon are stable and are not expected to fall for at least another 10 – 14 days if there is no further rainfall.
There is flow in the ditches at Finchdean and Dean Lane End. Over 1,000 litres per second was measured flowing through Dean Lane End on 9th January. If there is no further rain, groundwater levels are expected to begin to fall in Finchdean in 5 – 10 days.
HOW TO OBTAIN FURTHER INFORMATION
We try to refer to as many communities as possible in the newsletter, but we cannot mention them all. If you require further information, please contact Catherine McGee (01962 764835) or Alison Rennie (01962 764842). Alternatively, you can email us at firstname.lastname@example.org. If you are concerned about river flooding, please contact Nigel Sell (01962 764904).
If you know of anyone else who would like to receive this newsletter by e:mail, please contact Catherine Christophers on 01962 713267 or email Catherine – email@example.com.
GROUNDWATER ON THE INTERNET
The latest version of the newsletter is available on the Environment Agency website at www.environment-agency.gov.uk. The newsletter is in the Southern Region section which can be found by clicking on the map of England and Wales on the bottom right of the Environment Agency Home Page. The newsletter and attached graphs can be viewed in the Water Resources section of the Hampshire & IOW Area pages. Twice weekly updates from the five telemetered boreholes in Hampshire are available in the latest water levels section.
Information can also be obtained from Floodline on 0845 9881188. Callers can hear up to date recorded information on the groundwater situation by selecting Option 1. They are then are prompted to enter a quick-dial number, which will transfer them directly to the latest message for their area. The quickdial number for groundwater information in Hampshire is 01226. We hope to update the message twice a week at the moment.
NB – Groundwater Levels are shown on the accompanying graphs as mAOD – metres Above Ordnance Datum