A blow well outflows in the coastal plain as opposed to a spring found at the bottom of a hill or slope. It is between Louth and Barton-Upon Humber that the geological conditions for blow well formation are found. The chalk that forms the Lincolnshire Wolds extends beneath the Lincolnshire Marsh and continues under the Humber Estuary. Rainfall which occurs over the Lincolnshire Wolds percolates down to the water table and follows the chalk under the Marsh towards Humber Estuary. Ground beneath the marsh is typically clayey and covers the chalk and the groundwater it contains. The groundwater here is under pressure (artesian) and where there is an opening in the clays from the chalk to the surface and there is enough pressure, groundwater can emerge at surface. It is set of circumstances that differentiates a blow well from other types of spring.
The LCSP co-ordinates a working group of partner organisations with a keen interest in preventing the loss of these unique habitats. If you would like more information contact us.