Estuary
Pictured above is the estuary of the River Teifi (Afon Teifi).
There are many different variations of an estuary, but in most basic terms it is defined as the tidal mouth of a river where the tide and stream meet. It is semi-enclosed and is connected to the sea, so estuaries generally contain seawater (or coastal brackish water) mixed with freshwater that has drained from the land. However, some estuaries - particularly those along freshwater lakes before connecting to the sea and so may not mix with seawater.
Estuaries often have an identifiable ecosystems and act as natural filters for runoff to support plant, bird, fish and other animal communities by providing food, breeding grounds and places to rest during migration. They can be susceptible to degradation based on conditions such as erosion, overdevelopment and pollution.
As transition zones between freshwater and seawater, estuaries display oceanic properties, experiencing rising tides and waves and registering saltwater content. They also mimic the properties of rivers by registering freshwater flow and producing sediment.
The four most common types of estuaries classified by their geology are:
Estuaries can also be classified by their water circulation patterns. The most common types are salt wedge, partially mixed, well-mixed, inverse and intermittent.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Plumbing and heating for sustainability in new properties
Technical Engineer runs through changes in regulations, innovations in materials, and product systems.
Awareness of the Carbon Border Adjustment Mechanism
What CBAM is and what to do about it.
The new towns and strategic environmental assessments
12 locations of the New Towns Taskforce reduced to 7 within the new towns draft programme and open consultation.
Buildings that changed the future of architecture. Book review.
The Sustainability Pathfinder© Handbook
Built environment agency launches free Pathfinder© tool to help businesses progress sustainability strategies.
Government outcome to the late payment consultation, ECA reacts.
IHBC 2025 Gus Astley Student Award winners
Work on the role of hewing in UK historic conservation a win for Jack Parker of Oxford Brookes University.
Future Homes Building Standards and plug-in solar
Parts F and L amendments, the availability of solar panels and industry responses.
How later living housing can help solve the housing crisis
Unlocking homes, unlocking lives.
Preparing safety case reports for HRBs under the BSA
A new practical guide to preparing structural inputs for safety cases and safety case reports published by IStructE.
Male construction workers and prostate cancer
CIOB and Prostate Cancer UK encourage awareness of prostate cancer risks, and what to do about it.
The changed R&D tax landscape for Architects
Specialist gives a recap on tax changes for Research and Development, via the ACA newsletter.
Structured product data as a competitive advantage
NBS explain why accessible product data that works across digital systems is key.
Welsh retrofit workforce assessment
Welsh Government report confirms Wales faces major electrical skills shortage, warns ECA.
A now architectural practice looks back at its concept project for a sustainable oceanic settlement 25 years on.
Copyright and Artificial Intelligence
Government report and back track on copyright opt out for AI training but no clear preferred alternative as yet.
Embedding AI tools into architectural education
Beyond the render: LMU share how student led research is shaping the future of visualisation workflows.
Why document control still fails UK construction projects
A Chartered Quantity Surveyor explains what needs to change and how.
Inspiration for a new 2026 wave of Irish construction professionals.
New planning reforms and Warm Homes Bill
Take centre stage at UK Construction Week London.