Hydrogeological Impact Appraisal HIA
A hydrogeological impact appraisal (HIA) is a methodology designed to fit into the Environment Agency’s abstraction licensing process, including the changes brought about by the Water Act 2003. It also fits within the Environment Agency's overall approach to environmental risk assessment and can be matched to the risk of environmental impact associated with dewatering.
The HIA should include a conceptual understanding of the groundwater system and a survey to identify water-related features that could be affected by the dewatering e.g. water supply boreholes, rivers and protected sites. The assessment is backed up by calculations of the dewatering rates and the predicted impact (groundwater level drawdown) on nearby water features. A tiered approach is taken, with the level of detail, time and cost depending on the sensitivity of the site (presence or absence of rivers, protected sites etc.) and the scale of dewatering.
For sites where high dewatering rates are needed and/or in sensitive areas, the HIA may require extensive ground investigation, water features survey(s), pumping test(s) and stream/spring monitoring. This is likely to take several months. Once the HIA is completed and submitted, the regulator has up to four months to assess the application.
Additional guidance on HIAs is available through the Environment Agency.
[edit] Related articles on Designing Buildings
- Dewatering construction sites.
- Environment Agency.
- Environmental impact assessment EIA.
- Groundwater.
- Groundwater control.
- Hydrogeology.
- Raising awareness of dewatering regulation.
- Water abstraction licence.
- Water impoundment licence.
[edit] External resources
Featured articles and news
Celebrating architecture's eloquent champions.
Unusual perspectives on 1960s’ thinking.
AI and the challenges to intellectual property
The legal landscape of adopting AI now and in the future.
Worrying landscape for Welsh construction SMEs revealed.
In recent risk factor analysis report completed by CIOB.
Construction Sport survey highlights risks of dehydration
Supporting construction workers to avoid dangers.
Can your business afford to ignore mental well-being?
£70 - 100 billion annually in UK construction sector.
Mental health in the construction industry
World Mental Health Day 10 October.
Construction awards provide relief in wake of ISG collapse
Spike in major infrastructure awards, housing up but short of targets, are ISG collapse impacts yet to come.
Biodiversity net gain with related updates and terms
Only 0.5% of applications subject to BNG in the context significant proposed changes to planning.
As political power has shifted from blue to red
Has planning now moved from brown to green?
The role of construction in tackling the biodiversity crisis
New CIOB Nature of Building digital series available now.
The Nature Towns and Cities initiative
Grants of up to 1 million for local councils and partners.
The continued ISG fall out October updates
Where to look for answers to frequently asked questions.
Building safety remediation programme for Wales
With 2024 October progress updates.
In major support package for small businesses.
Conservation and transformation
Reading Ruskin’s cultural heritage. Book review.