Why gardens stay waterlogged
Standing water has a limited set of causes: heavy clay soil that drains slowly, a compacted surface that water cannot pass through, a low spot with nowhere to go, or water arriving from higher ground or neighbouring roofs. Finding which applies comes before choosing a fix, because a drain installed for the wrong reason simply moves the puddle.
How a French drain works
A French drain is a gravel-filled trench, usually containing a perforated pipe, that collects water from the soil and carries it to a suitable outlet. The trench is lined with a membrane that lets water in while keeping soil out, so the drain does not silt up. It works by giving water an easier path than the surrounding ground, which is why the outlet matters as much as the trench.
When a soakaway is needed
A drain has to discharge somewhere, and where there is no ditch, stream or suitable surface drain to reach, a soakaway provides the destination. It is an underground void, filled with rubble or purpose-made crates, that holds water while it soaks into the surrounding soil. Soakaways only work where the ground can absorb water, so the soil is assessed before one is relied upon.
Drainage under lawns
A French drain can run beneath a lawn: the trench is excavated, the drain installed, and the surface re-soiled and re-turfed or re-seeded so the grass grows back over it. For lawns that stay wet because the surface is compacted rather than because water has nowhere to go, relieving compaction and improving the soil may do more than any pipe. A new lawn on properly prepared, drained ground is sometimes the cleanest reset.
Drainage and garden levels
Drainage and levels are planned together. Where a garden is being levelled, the new falls are set so water moves away from the house and seating areas, and drains are installed while the ground is open. Adding drainage after surfaces are laid means lifting them, so it is always cheaper to think about water first.
What affects the cost
The length and depth of drainage needed, the soil type, the outlet or soakaway required, access for machinery and what has to be reinstated on top all shape the cost. A small interceptor drain across a patio edge is a different job from draining a whole waterlogged lawn, so the assessment comes first.
Enquire about garden drainage
Send your postcode and a description of where water collects, ideally with photos after rain, through the quote form. Daniel is based in Sholing, Southampton, working within about 30 miles, and drainage work often forms part of a wider garden renovation.
Frequently asked questions
How do you fix a waterlogged garden?
First find the cause: heavy soil, compaction, a low spot or incoming water. Then choose the matching fix, whether that is a French drain, a soakaway, surface regrading or improving the soil itself.
When is a soakaway needed?
When collected water has no suitable outlet to run to, a soakaway lets it disperse into the ground, provided the surrounding soil can absorb it.
Can a French drain go under a lawn?
Yes. The trench is excavated, the drain installed and the surface reinstated with soil and turf or seed, so the grass grows back over it.
Will a French drain work in clay soil?
It can, because the drain gives water an easier path than the clay around it, but the design and outlet have to suit heavy ground. The soil is assessed before a solution is promised.