KNOWLEDGE BASE

Flood wall costs

Flood wall costs

How much does a flood wall cost to protect your home or property?

Most flood walls are less than 2m in height to protect homes and property. The cost of a flood wall depends on a number of factors:

Height of wall
Soil type
The scale of the project
The materials to build the wall
Site constraints

We have designed two flood wall types, one for clay soils and the other for sandy/gravelly soils.

Flood wall cost per linear metre guide

Height (mm)	Clay Design	Sandy Design
675	£300 lm	£350 lm
900	£350 lm	£390 lm
1125	£390 lm	£425 lm
1350	£425 lm	£465 lm
1575	£465 lm	£510 lm
1800	£510 lm	£560 lm
2025	£550 lm	£590 lm
2250	£590 lm	£625 lm

The sandy/gravelly design includes the cost of the down stand 300mm wide x 600mm deep to reduce the risk of piping and to slow down the seepage rate.

NOTE

Please note the rates above are approximate. The exact cost of your flood defence wall will depend on soil type, scale, and location. For example a 10m long wall will cost more than a 100m wall due to the scale of economy.

To obtain a up to date and correct budget tell us about your project and we can give you a budget to +- 10%

Flood wall designs

Flood defence wall design, flood wall costs

Water does not flow well in clay soils but does in sandy/gravelly soils. The flow of water allows water to seek under the wall over time. The rate of flow depends on the porosity of the soil. When water flows quickly, it can cause piping, and this is when the soil erodes away, and the flow increases.

To stop piping, we construct a cutoff wall, as you can see in the sandy/gravelly design. The cutoff wall may not prevent seepage but will slow it down.

Our flood wall design uses hollow blocks that are connected to the foundation using reinforced steel. The block cavity is filled with concrete creating a cantilever retaining wall, and the concrete cavity fill seals the block joints.

Some flood wall designs also include a pumping system. Water is allowed to flow into a sump, where it is pumped back over the flood wall.