Drainage and Slope Design for Tennis and Padel Courts

How quickly play resumes after rain on an outdoor court depends on drainage and slope design. A wrong slope comes back for years as ponding and early surface wear.

Drainage on tennis and padel courts works differently from football pitches. The playing area is small, the surface is usually hard or semi-hard, and ball bounce reacts to the smallest level difference. Court drainage is therefore solved with the right surface slope, the right surface type and a well-planned water collection system around the court.

Impermeable and permeable court systems

Impermeable systems

Acrylic-coated hard courts on concrete or asphalt, and most padel courts on concrete slabs, are in this group. Water runs off the surface, so the whole court is laid as a single plane, sloping from one side to the other or corner to corner.

Permeable systems

Surfaces on porous asphalt or porous concrete, sand-filled artificial grass and clay courts let water pass partly or fully through. A crushed stone drainage layer and drain lines are added to the base, and the surface slope can be lower.

How much slope?

• Tennis courts: International Tennis Federation (ITF) guidance for impermeable courts describes a single-plane slope of roughly 0.5–1%. Where possible the slope runs side to side rather than end to end, so players feel it less along the net.
• Padel courts: outdoor slabs usually get about 0.5–1% fall, with water leaving through drainage gaps under the glass walls or along the low side.
• Clay courts: lower surface slope; drainage relies largely on the layer build-up and drain lines.

A crown in the middle of the court, sloping two ways, is not recommended: it disturbs the bounce and the surface wears along the ridge.

Collecting water around the court

Run-off must be collected along the low side of the court:

• A grated linear drainage channel is installed along the low edge.
• The channel sits flush with, or just below, the surface level; there must be no step at the channel edge.
• Channels connect to the stormwater line or a manhole; sand traps and inspection points are planned for maintenance.
• Surrounding ground slopes away from the court, not into it. Water and mud from adjacent lawns is a common problem.

Common mistakes

1. Leaving low spots: a few millimetres of dip in asphalt or concrete becomes a permanent puddle and algae on an acrylic court.
2. Wrong slope direction: sending water to a side with no channel or to the court entrance.
3. Channel higher than the surface: water cannot reach it and ponds along the edge.
4. Ignoring perimeter drainage: run-off from a slope seeps under the court surface and causes blisters.
5. Blocking padel drainage gaps: details that close the water's exit at turf edges or under glass lead to ponding.

Link with the surface

Acrylic coatings need an even, impermeable base. Before coating, the court is flooded for a "flood test"; puddles left after 15–30 minutes are marked and filled with patching compound. On artificial grass courts, the perforated backing and the permeability of the base must work together.

SFS Engineering designs slope and drainage at the design stage of its tennis court and padel court projects and installs them with its own drainage products. For acrylic court care read our acrylic tennis court maintenance article.

Frequently Asked Questions

What slope should a tennis court have?

For impermeable hard courts a single-plane slope of about 0.5–1% is recommended. Permeable systems can use a lower slope.

Where does rainwater leave a padel court?

On outdoor padel courts the slab fall carries water to the low side and out through drainage gaps under the glass panels, into a perimeter channel.

How are puddles on a court fixed?

Before coating, a flood test locates low spots, which are filled with patching compound. On existing courts the surface is recoated after local repairs.

Is a perimeter drainage channel necessary?

On impermeable courts a channel along the low side where water collects is largely essential; otherwise water ponds at the court edge and on surrounding ground.

Get technical support for your project: SFS Engineering handles site survey, design, material selection and installation as a single contractor. Send us your dimensions and site details through our contact page and we will work out the right solution together.