- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 11 Sep 2020
Principal aquifers are layers of rock or drift deposits that have high intergranular and/or fracture permeability, meaning they usually provide a high level of water storage and transmission. They may support water supply and/or river base flow on a strategic scale. In most cases, principal aquifers are aquifers previously designated as major aquifers.
There are two types of secondary aquifer designation:
- Secondary A: permeable layers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of base flow to rivers. These are generally aquifers formerly classified as minor aquifers.
- Secondary B: predominantly lower permeability layers which may store and yield limited amounts of groundwater due to localised features such as fissures, thin permeable horizons and weathering. These are generally the water-bearing parts of the former non-aquifers.
 Related articles on Designing Buildings Wiki.
- Catchment flood management plans.
- Chalk aquifer.
- Flood and water management act.
- Flood risk.
- Groundwater control in urban areas.
- Pumps and dewatering equipment.
- Water Act 2014.
- Water conservation.
- Water consumption.
- Water engineering.
- Water framework directive.
- Water table.
- Why creating new ponds helps to protect the ecosystem.
Featured articles and news
Brick slip soffit systems and intricate brick features.
ICE event includes comments from Welsh Government Minister Julie James.
How to write them and what they should include.
Designing Buildings Wiki becomes the world's first website to adopt the new knowledge standard.
Assessing the most beneficial design elements.
Exploring different types of vinyl flooring.
New Government task force will build beauty into reformed planning process.
Five outstanding aspects of the profession.
The seismic strengthening of historic churches.
Results show guarded optimism and payment concerns.
Noteworthy navigable aqueducts.
Technology is making remote work a reality.