Stormwater Design Why is it important? How do we manage it better?
A good place to start is a quick refresher on what is stormwater. In short, it is rain, melted snow and any other precipitation falling from the sky. Such water has two fates. It can fall directly in bodies of water or be absorbed into the natural environment, thus a source of replenishment for plant, animals and water reserves. The second results manage when precipitation falls on impervious surfaces, such as streets, pavements and roofs, and causes a runoff effect. It is this latter flow that can wreak havoc on the environment and lead to flooding, erosion, property damage, habitat destruction and contaminated streams, rivers and other bodies of water.
These reasons alone provide a preliminary sense of the importance of stormwater management as it relates to new development projects and on-going site management. Now the question – how can we best manage stormwater and design the most effective system? The answer is not a short one as it is unique to each site and has to be designed with that mindset. However, there are a number of common points that come to mind.
First, what are some of the methods we use to protect against the negative effects of stormwater runoff? Pipes, storm drains, curbs and gutters make the short list. There are also detention basins, ditches and even creeks that may be useful – again based on the site landscape. But the tools alone are not enough. The design has to be well thought out. The key is to capture and hold the runoff as near to the source as possible and ultimately reduce the amount of total suspended solids and pollutants that are being released. Once the water is detained (or retained), design measures should be in place to remove pollutants before it infiltrates the groundwater, streams and wetlands.
There have been extensive studies in the area of sustainable stormwater management and the development of stormwater control measures (SCM) that include structural or engineered control devices and systems used to treat or store polluted stormwater. These efforts also address operational or procedural practices. One key best management practice (BMP) is to mirror the manner in which nature handles stormwater and incorporate it when planning building and site developments. This includes increasing topsoil, creating infiltration trenches and using porous pavement. Further “green” efforts in development involve approaches and technologies to capture and reuse stormwater. Attractive and functional greenscapes can provide a natural habitat while protecting water quality at the same time. These improvements not only clean and cool the environment but enriches livability and increases property value.
Along these same lines and equally important are the less obvious efforts that need to take place. To start, stormwater cannot be ignored. There needs to be practices in place to address funding for new developments but also in short and long-term programs to repair and replace aging infrastructure. Current regulations should be reviewed, and enforcement of existing and future ordinances needs to be maintained. Lastly, the importance of educating the community ought not be understated. Water quality and its impact on the environment affects us all.
Daniel J. Caldwell is co-founder and principal with Stout & Caldwell, LLC.