Climate change and urban growth is leading to more storms, which affect the ground surface. This is problematic for buildings, particularly houses, often causing surface or sewer flooding if unmanaged.
As civil engineers, it’s our job to create a residential or civil design and site drainage plan to offset this.
This plan provides the builder, landscaper, paver or drainage contactors with all the necessary information for siteworks to ensure footings are protected and stormwater is properly disposed.
Choosing the correct site levels and drainage plan protects the footing of a house from the excessive wetting and drying of soils. Without this, can lead to disastrous consequences – such as settlement of the footing or cracks in walls.
Before undertaking the stormwater design and construction services for a residential Adelaide building, we consider several factors.
To start the civil design process, we select an appropriate bench floor level. After determining this, an equal cut is implemented, indicating no importation or cutting of soil (as the cut soils can become fill, making a flat sit to construct the house). Lower bench levels might lead to the cutting away of soil or the increased height of retaining walls. Flooding issues are synonymous with low bench levels.
Figure 1: Leveling by cut and fill
If a higher bench level is set, it might contribute to an increase in construction expenditure, due to importing soil. Neighbouring properties also need to be taken into consideration when choosing the bench level.
Figure 2: Drainage by gravity
For all stormwater drainage system designs, the bench level is the critical factor. As a general rule, a higher bench level is more desirable, as stormwater flows to the road by gravity. If the bench level is low, a sump pump station can be adopted to discharge the stormwater to the street. Although effective, it’s an expensive and often complex solution that should be avoided.
Figure 3: Comparison between house with pump and without pump
It’s important to engage a team of Adelaide’s construction service experts, as councils have different policies regarding stormwater requirements.
Some councils require the installation of detention tanks to slow the flow of stormwater onto the street. Not knowing this could lead to (costly) delays in new builds. Stormwater designs that are incorrectly mapped out can cause major damage to the house, or worse, council infrastructure and other properties.
It’s important to engage a team of Adelaide’s construction service experts, as councils have different policies regarding stormwater requirements.
Some councils require the installation of detention tanks to slow the flow of stormwater onto the street. Not knowing this could lead to (costly) delays in new builds. Stormwater designs that are incorrectly mapped out can cause major damage to the house, or worse, council infrastructure and other properties.
Figure 4: Comparison between house with detention tank and without detention tank.
There’s a host of other problems that arise from incorrect stormwater design such as soil heave, building dampness, corrosion, and mosquito issues (attracted to the pool of water).
There’s only one, sure way to avoid this: work with civil engineers.
Figure 5: Issues due to inadequate drainage.
During the construction phase, it’s a builder’s responsibility to ensure the management and disposal of stormwater. Upon handover, it’s usually the homeowner’s responsibility to fulfill the site drainage and paving. We work alongside licensed landscaping contractors to ensure your property is draining the water correctly (to the rules set in place by your local council).
For all stormwater design advice and services, talk to our construction professionals. Start by booking a free 20-minute consultation with Naveesh, our leading consulting civil engineer in Adelaide.