What should you know about stormwater detention tanks?

In case one is constructing a new home or a factory, there may be many stipulations of local councils that must be met. Based on where one is located, one needs maybe effective planning for dealing with stormwater and installation of stormwater detention tank .

Stormwater detention tanks are different from retention tanks. The latter are tanks used to store water harvested from rooftops (rainfall) or/ and hard surfaces on your premises (stormwater). They are called retention tanks because water is stored to be used for any other objective like watering plants or washing cars instead of being simply permitted to drain.

OSD (On-site Stormwater Detention) tanks are constructed mostly with new homes as part of the home drainage system. Detention implies that the water will be ‘detained’ for a limited period. OSD tanks are meant to remain empty except during rainfall periods and for a short time afterwards.

As opposed to retention tanks, the distinctive feature of an OSD tank is that it is specially fitted with a valve for the slow release of water over time. The OSD tank can be included in the system of sewer networks at factories or water treatment plants. It helps to deal with peak flows in such systems, avoiding overflow and protecting areas downstream.

What is stormwater? It is any kind of precipitation such as snow or rain which melts on contact with any surface, including the earth. Such water may evaporate, get absorbed by vegetation or seep into the ground. In case it doesn’t, stormwater will turn into surface run-off, flowing away from the land and into lakes, rivers, streams, or storm drains. Stormwater can emerge from all kinds of land, whether commercial, industrial, agricultural or residential.

Why are OSDs important? There can be many problems created by stormwater. Firstly, because of the timing and volume of surface run-off water and secondly because of the pollution it carries.

As for an environment that is not disturbed by human development , there is natural processing of water via the water cycle. The atmosphere of the earth continues to absorb water from the surface of the earth, purifies it and returns it as precipitation that benefits all life on earth. After this, water evaporates again, and the cycle resumes.

But when the environment is impacted by human activities (construction of buildings and roads), there is interference in the capacity of water to be absorbed back into the soil. Thus, the natural cycle of water is disturbed.

When storm sewers are constructed for rapid drainage, they further change the established path for stormwater flow and impact the process of natural water absorption. This can lead to soil erosion and also the transport of toxic chemicals and debris like fertilizers, grease & oil, animal faeces, pesticides and other contaminants. Hence, there is a need to heal the water cycle and deal with stormwater.

Benefits of OSDs There are many benefits of OSDs. Firstly, management of stormwater by using detention tanks encourages sustainability of the environment by reducing the flow of polluted stormwater, thus saving lakes, rivers and streams.

Secondly, the controlled release of stormwater by OSDs prevents flooding of surrounding areas and surface run-off and helps in effective dealing with stormwater.

Thirdly, a well-designed OSD will stop the flow of floating refuse, silt and any other contaminants, which augurs well for human health. It will store and release water in a controlled manner.

In sum, OSD systems have the potential to support community safety by lowering the risk of soil erosion and urban flooding. It can be utilized as a cost-cutting process when demand by the human population exceeds the availability of useful water. When stormwater detention tanks and other effective techniques are used widely, urban environments can become self-sustaining in terms of water.