Hertfordshire County Council has said that the ground in the county is particularly vulnerable to water damage because it is mostly clay and chalk. The Watford Observer has rounded up several of the sinkholes that have appeared in the area this year:The sinkhole in Hagden Lane, Watford, after it was excavated (Image: Hertfordshire County Council)This key West Watford road has been blocked by a sinkhole THREE times, all in the early part of the year. Depression in the road surface in Oxhey Road (Image: Hertfordshire County Council)This busy Watford junction was closed earlier this month after a sinkhole depression in the road surface was reported. This caused traffic woes at the busy crossroad junction of Eastbury Road, Deacons Hill, and Oxhey Road. Hayling RoadThis South Oxhey sinkhole required specialist equipment and took weeks to fix.