It's a highly efficient and environmentally friendly way to deal with excess surface water. The pipe leading into the
Quite simply, a soakaway is a hole in the ground that is filled that allows water runoff to slowly drain and redistribute itself into the soil.
Soakaways should last the life of the house, at least 100 years but only if installed and maintained correctly.
An attenuation system is the best option where local conditions don't allow for a soakaway. It can also be a useful way of harvesting water for other uses such as gardening, car washing and toilet flushing. This reduces the cost of a metered water supply and creates a more sustainable water management system.
For an easy-to-access garden, you can expect a small soakaway to cost around £1,000. For more complex designs, soakaways can take up to two days to install and therefore are likely to cost around £2,500. Broken down, labour costs average around £240 per day.
If you are installing a replacement Soakaway then you will generally not require planning permission. If you are installing a new foul Soakaway or drainage field you should at least inform your local planning office. For all types of Soakaway, Building Control guidelines are required to be followed.
To summarise the difference between the two, a drainage field is designed to add additional treatment to the water. Whereas a soakaway is designed to store a large volume of water allowing time for it to release into the ground (i. e. in a heavy downpour).
Whilst soakaways indeed are low maintenance and reliable, as the drainage is natural, if they go wrong for any reason, it could lead to potential issues. The cons of soakaways include: They can get blocked by dirt and leaves when not fitted with a silt filter which can result in a soakaway overflowing.
The depth of the soakaway depends on the soil. Usually, the council will only accept soakaways of up to 2.5m deep for dwelling. This is because deeper soakaway tends to carry risk to the stability of houses should they need to be removed in the future.
Essentially, an oversaturated soakaway will stop processing waste water as there simply isn't enough space for more water to enter the system.
A properly installed soakaway generally requires little maintenance, but if it becomes blocked this will reduce how efficiently it manages rainwater. If left unresolved, this can eventually lead to problems.
A well-designed leach field will last between 15 and 50 years. The dramatic lifespan difference is based on several factors, including: Maintenance – Regular inspections and pumping every 5-10 years can extend the field's functional life.
Constructional Features of Soakaway Pits
The pit depth should be 1 to 5 meters, depending on the surrounding water table. It is recommended that the pit's depth should not be below the water table to avoid any water contamination issues.
Traditionally, soakaways were filled with gravel and rubble instead of soakaway crates. These days we recommend using crates as they save time, provide a long-term solution to surface water issues, and are incredibly sturdy and durable.
Is a French drain the same as a soakaway? No. Unlike soakaways, which are a pit in the ground into which you run your rainwater drainage. French drains are used to prevent water logging and an excess of surface water.
A soakaway consists of a hole dug in the ground and filled with rubble or plastic crates. It provides a solution to excess surface water by letting it slowly drain and soak into the ground instead of build up.
Soakaways should be:
sited at least 5m from the foundations of a building. sited to take account of topography, ensuring that water is drained away from the building. in soil of low permeability, only provided where no alternative system is available.
Installing soakaways is fairly straightforward, but it's always good to make sure you know exactly what you're doing and what you need for the job. Whether you need more information about building your whole soak away, or just want to know what kind of material you should use for the backfilling, we're here to help.
The most common cause of a failed soakaway drain system is poor installation. This generally occurs when no filters have been installed, or the soakaway itself is too deep. As well as poor installation, another common problem is a lack of planning by inexperienced businesses.
We strongly recommend consulting a drainage engineer and having the all of the calculations and tests performed correctly before proceeding. So as a very basic rule of thumb, for 50m2 of roof area you may be able to get away with 1m3 of water storage space.
DON'T install a soakaway in heavy clay soil, the water cannot drain through this so it won't work if this is in your garden. DON'T install a soakaway if you live in a polluted area prone to smog. Soakaways are no appropriate for polluted rainwater.
Do All Septic Tanks Need a Soakaway? In general, the answer is yes – in fact, all septic tanks must have some form of drainage available to allow the treated wastewater to drain away. One exception is that some tanks discharge directly into a water course, such as a ditch, a river or lake.
A rainwater soakaway is a drainage trench that is dug from surrounding soil in order to manage surface water through a septic tank or and alternative drainage route. Rainwater soakaways are usually made from gravel or stone or even plastic soakaway crates.
It will work but not for long. You need a storage tank to give the raw sewage a place to liquefy. The natural bacteria start digesting it and turn it into “gray water”. It's that “processed” water that goes into the leach field.