- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 29 Mar 2019
The ‘water table’ is the below-ground level that marks the transition between ground that is saturated with water and ground that is not saturated. The upper, unsaturated level, is known as the 'capillary fringe' or 'zone of aeration'. The lower, saturated level, is known as the 'zone of saturation'. An aquifer is a pocket of water that is found below the water table.
As water moves down from the surface it filters through sediments and rocks and causes the water table to fluctuate. The water table typically follows the topography of the above-ground land, but sometimes intersects with the land surface, which may be evident from the presence of spring or oasis.
The level of the water table is influenced by:
- Geology: Heavy, dense rocks are capable of holding less water than light, porous rocks.
- Weather: which is why it tends to fluctuate seasonally.
- Extraction: for industrial purposes, drinking water and so on.
- The way land is used: it is common for urban areas to have predominantly impervious surfaces such as roads, car parks and public spaces, and these prevent the seepage of water into the ground. Instead it becomes run off, and the water table can dip as a result.
 Related articles on Designing Buildings Wiki
Featured articles and news
Guidance for local authorities and consultancies setting planning conditions.
A real deal – at last?
How does anastylosis help in the reconstructing of ancient monuments?
More than just aesthetic and historic values and meanings.
An exciting and novel collaboration between the RIBA and the SPAB.
Republic of Ireland updates to planning and development.
The different types of pile foundation.
Achieving a net-zero carbon UK by 2050.
Responding to an invitation to tender.
Statutory instruments laid in Parliament to amend the Climate Change Act.
How will we pay for infrastructure post-Brexit after EIB has gone?