Groundwater
The term 'groundwater' refers to all water which is below the surface of the ground and within the permanently saturated zone. A groundwater body is a distinct volume of groundwater within an aquifer. The term ‘hydrogeology’ refers to the nature, distribution and movement of groundwater in soils and rocks, including in aquifers. Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
Groundwater is an important part of the water cycle which continually moves water through the environment. Water evaporates from the oceans and condenses into clouds, before falling onto land as rain and flowing into rivers and back into the oceans.
However, the ground has the potential to interrupt this cycle, absorbing rainwater like a sponge. Some of this water will return to the atmosphere through processes such as transpiration, while some will infiltrate deeper into the ground where it becomes groundwater.
The water table is the level at which the ground becomes saturated and water will flow to a point of discharge such as a spring, lake, river or sea. Groundwater plays a vital role in supporting industry, wells, wetlands, stream flows, and so on. The water table may rise during periods of heavy rain or melting snow, or fall during drier periods, or as a result of extraction.
In some parts of the world, water shortages can be experienced when groundwater supplies are used faster than they are replenished, while in other regions, groundwater can cause flooding or can become polluted by human activities such as industry and agriculture.
Nearly 30% of global freshwater originates from groundwater, and almost all the water used for agriculture, industry and drinking will have been groundwater at some point in its cycle.
Some geological formations are impermeable to groundwater whilst others are permeable. Permeable formations – known as aquifers – have fine holes or networks of fine cracks that allow water to flow through them. The size of the spaces in the soil or rock, as well as how well they are connected, determines the speed of groundwater flow.
In the UK, hydrogeologists are work to ensure groundwater is maintained in sufficient supply with a quality that is protected. In developing countries, hydrogeologists may work on rural water supply projects to help provide safe and accessible water.
Notes:
- Groundwater-dependent terrestrial ecosystems are wetlands that are directly dependent on water from a groundwater body to maintain their form and function.
- Groundwater source protection zones are areas defined by the Environment Agency which show the risk from contamination/pollution to groundwater that is extracted for drinking water.
- According to the Groundwater Foundation, groundwater (or ground water) is ‘…water found underground in the cracks and spaces in soil, sand and rock. It is stored in and moves slowly through geologic formations of soil, sand and rocks called aquifers.’ Ref https://www.groundwater.org/get-informed/basics/whatis.html
- The unsaturated zone is: ‘The soil layer between the land surface and the groundwater level.’ Ref The SuDS Manual (C753), published by CIRIA in 2015.
- A groundwater body is: 'The principle reporting units for distinct volumes of groundwater within an aquifer or aquifers defined by the Water Framework Directive.’ Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014.
[edit] Related articles on Designing Buildings
- Chalk aquifer.
- Dowsing.
- Flood.
- Groundwater control.
- Groundwater control in urban areas.
- Groundwater flooding.
- Groundwater recharge.
- Groundwater source protection zone.
- Pumps and dewatering equipment.
- Raising awareness of dewatering regulation.
- River engineering.
- Types of water.
- Water engineering.
- Waterlogged.
- Water table.
Featured articles and news
Mental Health Awareness Week with ABS
Architects Benevolent Society programme of activity.
CLC publishes domestic retrofit competency framework
Roadmap of Skills for net zero.
May 13-19: Moving more for our mental health.
Understanding is key to conservation.
Open industry engagement survey seeks responses
Institutions and the importance of engagement.
National Retrofit Hub unveils new guide
Digital Building Logbooks and Retrofit: An Introduction.
Top 50 firms awarded 52bn of projects in the last year
New engineering data shows.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.
Noise in the built environment
BSRIA guide TG 20/2021.
17,000 people suffer conditions as a result of exposure to excessive noise at work.
Turning down the noise: Auditory health
A pervasive risk with far-reaching consequences.
Getting the most out of heat pumps and heating
How heat pumps work and how they work best.
Plumbing and heating for successful retrofit and renovation
Low temperature underfloor systems and heat pumps.
Cost-of-living crisis and home improvement plans
Starting on the right footing and top tips for projects.
Delays on construction projects
Types, mitigation and the acceleration of works.
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.