Marblaze Engineering and Drafting: Stormwater Management Optimization

Written by: Angelica Bilangel

What happens to Stormwater?

Think about how the water cycle works. When stormwater falls to the ground, it either streams down to the nearest body of water, evaporates, or infiltrates through the soil.

However, when stormwater reaches man-made surfaces, such as concrete and buildings - which are often solid and level - the cycle is disrupted and stormwater runoff is increased. This is harmful in multiple ways, affecting people, the environment, and even buildings.

Stormwater Management

To prevent issues caused by stormwater runoff, including flooding, the stormwater must be managed. One of the major things that stormwater management relies on in order for it to work is gravity.

Gravity is what causes stormwater to fall from the sky and onto a roof or any other man-made surface, and those surfaces must be designed to let the water flow naturally into drainage pits.

Often, drainage systems are below ground, so it is possible to rely on gravity to push stormwater from buildings, pavements, and roads into drainage systems without much issue or needed maintenance.

Without the help of gravity

Sometimes, gravity can hinder the flow of water into the main drainage system. For instance, what if the location of the main drainage system is on a higher ground level than the building?

This is where stormwater management optimisation comes in. It involves strategies that prevent problems in drainage systems, both efficiently and with the least amount of cost.

Good examples of stormwater management optimisation includes these three solutions:

Water Pumps

One solution to moving water against gravity is by using a water pump. How this works is by letting the water fall into a collection tank. Once the water is inside the tank, the pump located at the bottom of the tank pushes the water upwards with ease and into the main drainage system.

While water pumps do work, there are some issues with the use of water pumps which don’t make it the most ideal method for stormwater management optimisation. Having a water tank is costly, each financially, in power, and requires monitoring and maintenance.

Often, these are used as a last resort.

Infiltration Systems

Another stormwater management strategy used to manage stormwater is by an infiltration system set-up. Here, stormwater that falls onto man-made surfaces and then collected by infiltration systems finds its way to soil and into the earth. The ways in which Infiltration systems can be set up are extremely versatile. They are also a cheaper option, especially compared to systems including water pumps. Using this method helps to prevent flooding in concrete areas, and is also good for the environment.

However, the efficiency of one is dependent on the kind of soil type that surrounds the system. Soil types such as clay make it much more difficult for water to infiltrate through, while sand makes it much easier. It is also not an unlikely occurrence for the system to be clogged, and therefore will need regular maintenance.

Sealed Systems

Sealed systems are another good option for stormwater management. These systems use pressure caused from gravity (stormwater from the roof to the ground) to push water upwards in a diagonally placed pipe.

A downside to this strategy is that the system only moves when stormwater runs in the pipes. Therefore, when the rain stops, there will always be water inside, which can lead to issues such as creating a breeding ground for mosquitoes. It is also required for there to be a reasonable height for the stormwater to come down from so that its force is strong enough to push water upwards.

Combining Strategies

When thinking about stormwater management optimisation, it is important to be innovative with strategies. For instance, in a scenario where the ground level of a building is lower than the ground level of the road, it is possible to use any one of the above options. However, knowing the cons of each, only one of them is not enough to be the best option for stormwater management optimisation.

Therefore, for effective results, a combination of methods and strategies to be used to create various strategies. An example of this is by building a sealed system as a base, with an opening to an infiltration system to drain the excess water while the sealed system is not moving.

Also consider how every site is different. Because of this, each site should be assessed individually to determine the right set-up for stormwater management optimisation.

Need help with Stormwater Management Optimisation?

Now that we know the basics of stormwater management optimisation, what now? If you ever need help with stormwater management optimisation, the best option is to seek a qualified stormwater engineer.

For any of your stormwater management needs, please contact Ariel Bilangel at ariel@magryn.com.au.