Water is a vital commodity in our lives, but it is possible to have too much water all at once in our lives, especially following violent storms or snow melt. This excess water, lying on the ground, swelling rivers, canals and drains to over-capacity is known as stormwater.
In order to make the best use of this water, local authorities need to safely contain stormwater while any contaminants or pollution is removed and disposed of safely – this guest post from stormwater management experts Liquivault aims to tackle how this should be done.
To this end stormwater management experts use attenuation tanks as a large parts of urban planning. Attenuation tanks are large storage containers that are built into drainage systems, usually having much larger bore pipes than standard drains. In this way, storm water and run off can quickly flow into the tank, where it is then contained until the storm has passed. There are controls built into the attenuation tanks that allow engineers or waste water experts to increase or reduce the rate at which the water leaves the attenuation tank.
This means that while the drains are running at capacity, because the snow melt or precipitation is in full flow, the attenuation tank can be shut off so that it is not adding a further burden to the already over-worked system, but as soon as the drains are clear the attenuation tank can be drained quickly, so as to be ready for the next time.
Stormwater Filtration & Treatment Is Vital
Stormwater can often be very dirty and polluted, having run over oil and dirt caked roads before finding its way into the attenuation tank. Understanding this has led to water cleansing features being added to attenuation tanks. This is usually in the form of simple gravity-fed filtration through layers of fine sand and so on, to remove impurities and dirt.
Stormwater management falls under a much broader umbrella; that of waste water management in general. While in rural areas this may not be much different, in built-up urban areas this can include waste water from industry, recycling and managing domestic water and commercial water.
When planning waste water management in an urban area there are many points to consider, starting from the moment construction begins. Allowances must be made for the town to expand and grow, and the direction of growth must be taken into account, with easy access to enable future builders and developers to connect new suburbs into the system. To conserve the earth’s resources as much as possible, water should be recycled wherever possible, while making provision for the safe disposal ‘black’ water which cannot be reused or recycled.
Environmental Respect Is As Important As Urban Protection
In order to create a good working drainage system, the engineers should work with nature as much as possible, allowing gravity to carry some of the load and only using pumps when absolutely necessary. Every urban area will need a good reserve supply of water for drought years, and will equally need flood planning to be considered. Where there are rivers or canals running through the town, these can have their banks raised or even be covered over entirely to prevent it from flooding low-lying areas in the town.
The engineers and builders should make a study of the weather patterns of the area for as far back as possible, making sure that they are not building new houses in the middle of an ancient flood plain and that their drainage system will flow freely until the water is a good distance away from the town. Attenuation tanks should be placed at the point where a maximum amount of run-off will accumulate, as this will mean that the worst of the flood risk can be quickly and safely removed, and held until it is safe to reintroduce it into the water management system.
Refine Collected Water For Reuse
An excellent plan would see this collected water being introduced to the water refining system and then being recycled into homes and businesses. In this way, stormwater that could otherwise be an unwanted nuisance can be of good use to the community that it was a threat to!
Looking at the water needs of the community as a whole should take into account the most important needs, such as water to drink, bathe in and use to remove waste from our homes, as well as the lesser needs, such as filling up swimming pools and keeping lawns green and fresh. Industries and commercial establishments will also have specific needs that must be factored into any plans
However, removing unwanted water should also hold a high priority. Run off from heavy rain or snow melt, and blockages or delays in the drainage system due to debris in the pipes or simply too much water in the system should be included in all calculations before the drainage and water systems are put in place. The best waste water management system is one that is taken for granted by the people who use it day in and day out!
This article was written by Tom McShane – environmental blogger and writer working with stormwater management specialists Liquivault for this post.