- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 12 Oct 2020
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.
The SuDS Manual (C753), published by CIRIA in 2015 defines the water table as: 'The point where the surface of groundwater can be detected. The water table may change with the seasons and with annual rainfall.'
 Related articles on Designing Buildings Wiki
Featured articles and news
Heritage on the edge?
Prioritising tax considerations.
The four D creative process: discover, define, develop and deliver.
National Cyber Security Centre initiative is announced.
Reviewing trends and projections.
Legislation will establish initiatives to move towards net zero.
How to document contractor employment status.
Tech tools to help manage people and space post-pandemic.
A style that ranges from mock Tudor to arts and crafts to the 'Wrenaissance'.
Free guide from Secured by Design.
BREEAM strategy for sustainability and the circular economy.
Free tool to improve the construction programming process.
Are buildings doing what they're supposed to be doing?
Cities with quick access to everything by foot or bike.