Drainage Soil testing – An integral part of your sports turf & landscape construction projects

Good drainage is critical to maximise the performance of any turf construction project (sports field, golf green, racetrack etc.) or landscaping project (lawns, amenity parklands, garden beds etc.).

 There are several factors that influence how well a surface will drain including: 

  • The rootzone material or topsoil used. In soil, water flows down through the open pores between the soil particles. The volume of flow is dependent on the total pore space, pore size distribution (i.e., transmission pores) and the continuity between them and this is primarily determined by the soil’s particle size distribution, particle shape & arrangement (structure).
  • Surface levels (localised depressions) & gradient or shape. These are critical factors as the longer the period that excess water remains on the surface, the greater the potential for the surface to be damaged during use.
  • Compaction due to heavy use or intensive maintenance practices will reduce the amount of water that can move into (infiltration) and down through (drainage) the soil. Compaction will also reduce aeration (air exchange) which is necessary for root growth and microbial activity.

Most of our community sports fields and parklands are constructed from fine-textured local soils which have a significant clay and/or silt content (e.g., clay loams & sandy loams). 

These soils have poor drainage and are prone to compaction and waterlogging which can result in extremely soft surfaces in winter and extremely hard surfaces in summer. The slow draining nature of these local soils can also reduce their playability and usability in wet weather.

Sands are often used to construct high performance sports surfaces (e.g., premier sports fields, putting greens etc.). Sands have better drainage & aeration characteristics and are more resistant to compaction than heavier soils which is of great advantage in winter when these surfaces can become saturated. However, not all sands are suitable as many have poor drainage rates due to their particle size distribution and particle shape. 

In any project, poor drainage will result in the soil remaining saturated for longer than desired.  A saturated soil has an unstable surface that is easily damaged. When a saturated soil is played on or even trafficked by vehicles (e.g., mowers), the surface can quickly ‘cut-up’ result in significant surface damage.

When selecting materials to be used for construction purposes, the drainage rate, permeability or more technically the saturated hydraulic conductivity of the rootzone material or topsoil is of major importance.