What is a dike breach pond (Dutch: wiel)?

A dike breach pond, in Dutch “wiel”, is a deep, often round pool lying against a dike, formed by a local dike breach. When a dike breaks, water rushes through the gap with great force and scours a deep hole in the ground behind it. After the dike was repaired, that hole often remained as a pond. Other Dutch names are “waai”, “waal” and “weel”.

How it forms

1. During high water a dike fails over a short length.
2. The inflowing water swirls behind the dike and washes the soil away.
3. A deep scour hole forms, often much deeper than the surroundings.
4. Because the hole was too deep to fill easily, the new dike was often built in a curve around the pond.

How to spot one

• A round or oval pond right against a dike.
• A noticeable kink or bend in the dike around the pond.
• Place and field names containing “wiel”, “waai” or “weel”.
• Old maps and elevation maps (in the Netherlands the AHN) often show breach ponds and former dike lines clearly.

Value

• Heritage: visible traces of past floods, often protected as landscape features.
• Nature: many breach ponds are valuable habitats with their own aquatic and bank vegetation.

Tips for building nearby

1. Soft, variable ground: banks are often filled with silt or sand. Get a ground investigation before designing foundations.
2. Seepage: groundwater can rise near the dike. Expect damp crawl spaces and basements.
3. Protection zones: close to dikes and ponds, building, digging or planting often needs consent from the water authority.
4. Filling in: filling a breach pond is usually not allowed and is technically difficult.

Related terms

• Emergency dike
• Pile dike
• Stone dike
• Toe of a dike
• Aquifer

Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.