Boggy lawns are a pretty common problem for homeowners in Auckland, where many areas have clay soils. High-density soils such as clay soil and compacted soil have low percolation, which means they drain water slowly. As such, they tend to get waterlogged easily in a flash rain, resulting in a soggy lawn.
Having a boggy lawn can be problematic in a number of ways. For one, it can cause flooding. In the event of a heavy rain, the surface water from your lawn might find its way into your basement. Things can get really messy and costly to deal with. If you are growing a garden, poor drainage can drown your flowers and vegetation.
Fortunately, there are a number of subsoil solutions for soggy lawns. The right method will depend on how big your lawn is, how often it gets wet and how long it remains wet.
If the lawn is relatively small, it might be easier to eliminate the problem rather than solve it. In other words, you might want to consider altering your lawn. A well-draining soil needs air in it. In the case of clay, the tiny soil particles are compacted so they don’t allow much room for air. To manage this, you can introduce lots of organic matter such as compost and aged manure to lighten the soil. Organic matter will force the tightly packed soil particles apart, resulting in improved drainage. If you are growing a garden, another option for you is to build raised beds on top of the clay. Planting a cover crop with a deep root system, such as clover, turnip and alfalfa, can also aerate the soil.
If altering your lawn isn’t an option or if your soil is heavy clay, a more effective solution is to install underground drainage pipes or tiles. This is done by laying clay or plastic pipes beneath the ground to create a soakaway that will drain the water off your lawn. A soakaway is a hole dug in the ground that’s filled with coarse stones, gravel or any material that will allow the runoff to percolate back into the ground faster.
It might sound like a project you can DIY, but it’s a lot of physical labour and can become costly if you make even a small mistake. It also requires precise engineering to ensure proper water runoff and percolation in even the heaviest rains.
We know this very well and we’ve seen a lot of botched DIY attempts at managing a clay lawn, which is why Drainage NZ offers affordable, engineered basement and garage flooding solutions for Auckland. We remedy boggy lawns by installing compliant garden drainage. The process involves soil assessment and percolation tests, so we can determine exactly how to work around your lawn.
Once we have determined the ground slope, percolation rate and the proper location for the drainage pipes, we’ll build a trench filled with loose soil or gravel that will receive the surface water. This is also where the drainage pipes will be laid. The width of the drainage area will depend on the rate at which water must be absorbed back into the ground. If the lawn tends to get waterlogged relatively fast, the trench will have to be larger and filled with gravel instead of loose soil. The drainage pipe used here has special holes in them to allow the water in the trench to enter and be swiftly carried away to a catch area.
The good thing about this solution is it can be integrated into your garden design. It doesn’t have to be an odd line of gravel around your lawn as the drain can be covered by turf or made into an attractive footpath.