Understanding your residential drainage system
The drainage system helps minimise the risks of flooding by carrying stormwater safely away from homes to creeks and rivers and discharging your home wastewater into the main sewer line. Properly functioning and well-maintained drainage systems are essential as poor drainage can lead to many problems.
When designing and building your house, it is crucial to consider its drainage system. At the outset, it must be in accordance with the Plumbing Code of Australia (PCA) to ensure its quality and durability.
What makes up a residential drainage system?
A drainage system is a large network of pipes that starts from home gutters, downpipes, and pipelines, which fall under the responsibility of the homeowners. It then connects to the drainage system that spans towns and cities to ensure that neighbourhoods will not be flooded.
Residential drainage systems help in ensuring that stormwater and household water wastes directly go to the sewer. As mentioned, when building your house, it is vital to ensure that the drainage plan is included. A house with a faulty drainage plan can be disastrous, for you and your property as well.
You must ensure that your home’s drainage system is complete and working. Improper and incorrect installation of your home’s drainage can lead to leaks, damaged roof, damaged foundation, growth of moulds and mildew, and even flooding.
Here are the components of a complete and functional residential drainage system:
Stormwater Drainage System
Stormwater, if not directed properly to the main drainage system of your neighbourhood, can cause you serious problems. Your house’s drainage system should include provisions for stormwater. Having a rainwater collection system also allows you to use the water for cleaning or watering your lawn and landscape. You may likewise choose to direct all the stormwater to your city’s main lines.
- Gutter Systems
Your gutter system is not only important for your roof, but it is also essential for your entire house. It is the first line of defence of your home against the onslaught of stormwater, and it plays an important role in your home’s drainage system.
Your gutter system has one function, and that is to divert stormwater away from your home, as well as your surroundings, such as your lawn and your driveway. Stormwater can ruin the things that you have worked hard for. It protects your house’s foundation, protects your lawn and landscaping, prevents soil erosion, protects your concrete paths and driveways, and prevents flooding in your basement. Gutters also protect your home’s paint job and help prevent the growth of mould and mildew.
Without your gutters, stormwater needs to go somewhere. Without any structure to stop it, it can go to any part of your home. It can damage your electrical wirings, your ceiling, and even your walls. Moisture is one of your home’s biggest enemies, which can result in costly and serious damage.
It can also go to your concrete driveway. Moisture can seep in, or worse, the force at which stormwater falls on your concrete can wear it down sooner than expected.
The same way that stormwater rushing down your roof can damage your driveway; it can also damage your manicured lawn and landscape.
- Downpipes
From the gutters, the downpipes take the stormwater down into someplace in the ground. It can go to your stormwater or rainwater collection system, or it can go directly to your city’s main underground drainage system. Like your gutters, its role is to direct stormwater away from your property and towards the main stormwater system of your municipality.
The amount of rain in your location can affect the specifications of your downpipes. Your downpipes come with accessories such as brackets, joiners, and offsets. They come in different sizes, depending on your needs.
Sewer Drainage System
Household water wastes should be directed efficiently to the city’s main sewer line. If not properly disposed of, it can cause unspeakable damage to your home, as well as pose serious health risks to you and your family.
Your sewer drainage system is made up of underground pipes that carry water wastes from your laundry, bathroom, kitchen, sinks, and other plumbing fixtures in your home. It carries sewage from your home to the main sewage system. These wastes go to your city’s treatment facility where rubbish and organic matter are removed. The treatment facilities may then use a process to recycle the water or direct the treated water to the nearest creek or river.
Your home’s sewer drainage system must include the following components:
- P-Traps
P-traps are located beneath your sinks, bathtubs, and other plumbing components. A P-trap is a curved section of your piping that’s shaped like a letter P, hence its name.
It holds standing water, which prevents sewer gases from rising from your sewer system and smelling inside your home.
- Toilet Traps
The toilet trap serves the same function as a P-trap. It is a curved drain that holds standing water, preventing sewer gases from rising.
- Clothes Washer Stand Pipe
This pipe is connected to your washing machine. The drain tube of your washing machine empties into an exposed standpipe, leading to a branch drain into your home’s main drain.
- Branch Drain Lines
These lines connect your home’s plumbing fixtures to the main drain lines. The drain lines are normally out of sight, hidden in your ceiling, walls, and floor.
- Soil Stack and Soil Stack Vent
Also known as main drain stacks, soil stacks are vertical pipes with a large diameter. The soil stack vent, located at the upper part of the standing soil stack, gives your sewer system venting. The soil stack vent extends upward and exits to your roof into the open air. This gives your sewer drainage system equal air pressure.
The stack vent serves two purposes: it carries toxic fumes away and allows pressure to be released, so that your wastewater can move downward freely.
- Main Drain Line
This pipe connects your home’s sewer system to your municipal’s main sewer system. This usually runs beneath the foundation slab of your home.
What is the difference between rainwater and stormwater?
You may see the two terms used interchangeably, but it is important to understand the difference between the two. Stormwater comes from rain and may be considered as rainwater. However, when it comes to drainage, the two are different.
Stormwater refers to the water that drains off the land during rainfall. This includes rain that falls on your roof and goes to your gutters, downpipes, and into your drains. It also includes rain that falls on the streets, gardens, driveways, and lawns, among many others.
Rainwater is the rain that only falls on your roof, which you can harvest using a rainwater harvesting system. It is of higher quality than stormwater, which carries with it organic matter, soil, litter, and oil residues.
While some homes invest in rainwater collection systems, there are those who invest in stormwater detention tanks. Unlike a rainwater collection tank, a stormwater tank is fitted with a valve. This is to allow the tank to release water slowly. A stormwater tank is a better alternative for collecting rainwater during heavy downpours.
Why are stormwater and sewer drainage systems separate?
It is necessary to separate the stormwater system from the sewer system.
For one, it helps prevent wastewater treatment systems from being overwhelmed during heavy rainfall. This could lead to the treatment system having to discharge untreated sewage water back into the environment.
When designing the stormwater and sewer systems for your home, make sure that there are no illegal cross-connects between them.
What are septic tanks?
Believe it or not, some houses are not connected to the main sewer lines of the municipality where they live. These residents rely on septic tanks for the treatment and disposal of their home sewage wastes.
Before everyone was connected to the main sewer lines, homeowners had a domestic wastewater treatment system with septic tanks.
Septic tanks are wastewater treatment structures buried underground. They are commonly used in places that do not have centralised sewer systems. A septic system consists of a septic tank and a drain field.
So how does it work?
- Wastewater runs out of your house through the main drainage pipe into a septic tank.
- The septic tank is a water-tight container usually made of concrete or polyethylene that is buried underground. It holds the wastewater for some time. During this period, solids settle down to the bottom of the tank, forming sludge, while the oil and grease float collectively at the top as scum.
- Scum is prevented by a T-shaped outlet from travelling into the drain field.
- The liquid wastewater, known as effluent, then flows out of the tank into the drain field.
- The drain field is a shallow excavation made in unsaturated soil. Pre-treated wastewater from the septic tank is discharged to the porous surfaces, allowing wastewater to filter through the soil. The soil then treats and disperses wastewater as it drains.
- The filtered wastewater is then discharged into the groundwater.
How to properly maintain your stormwater drainage system?
If you want to avoid mishaps and serious problems with your house’s stormwater drainage system, it is fundamental to do your own share of maintaining it. You can do the following:
- Keep your gutters free of dried leaves and debris.
- When your gutters are filled with foreign objects, water has nowhere to go and will spill over your roof into the ground.
- If you have trees in your yard, gutter guards can help keep your gutters free of blockages.
- Regularly check your gutters for leaks or damages. You would not want to wait until your gutters collapse on you in the middle of heavy rain.
- Cutting overhanging branches can also help clear your roof’s gutters.
- Your downpipes also need your attention. Make sure that your downpipes are connected properly.
- Watch out for cracks, rusts, and accumulation of soil in the gutters, among others.
How to properly maintain your sewer drainage system?
No one likes a clogged sink or toilet. However, how do you ensure that your sewer drainage system is working properly? A blockage in one of your lines can spell trouble for your household.
A blocked main drain can cause extreme convenience, discomfort, and even pose health risks. Clogged sinks and toilets can cause a huge inconvenience when they happen.
The best and most effective way to take care of your sewer drainage system is by taking preventive actions. Be mindful of what you throw down into your drain. Do not flush solid wastes, such as used napkins or tampons, in your toilet. Do not drain food scraps down your kitchen drainage.
You can use a drain guard in your sinks to limit the number of solids that will go down your sewer system. You can also use boiling water to wash out non-soluble products such as cooking oil and coffee grounds.
Remember not to pour any chemicals down your drain. It can lead to more trouble should the chemical be highly reactive or does not dissolve in water. Call a licensed residential plumber if you want someone to do a comprehensive check-up of your home’s sewer system. Plumbing experts can clean your main drain line to reduce the risks of main drain blockage.
Call Green Planet Plumbing for your plumbing needs.
Green Planet Plumbing offers unparalleled 24/7 plumbing services in Newcastle, Lake Macquarie, Central Coast, and Hunter Valley regions. We serve both residential and commercial structures, offering excellent installation, repair, and maintenance services.
Need to call us in the middle of the night for a plumbing emergency? Our plumbers will be happy to help you out. Call Green Planet Plumbing today at 02-4911-9402. Our team will be glad to assist you with your concerns.
