Hurricane Katrina is a wake-up call for Americans to start get serious about how nature strikes back. New Orleans is a major port in the southern end of the country where weather is humid and subtropical but as Katrina showed, it’s also a bull’s-eye for any hurricane. And despite the urban development in the city, it was not prepared for the fury of Katrina which placed much of it under water.
The Environmental Protection Agency (EPA) describes how roads, buildings, and other infrastructure affect storm water that falls in a particular area. According to the EPA, there’s more runoff in the city than in spacious rural areas because the asphalt and concrete in city roads prevent most of the water from seeping into the ground as it should. The opposite happens in the rural areas where fields can absorb much of the rainfall.
When rain falls on unscathed natural cover, 10 percent of rainfall flows as runoff to the tributary or reservoir nearby. Of the 50 percent rainfall absorbed by the earth, 25 percent flows in the shallow earth while 25 percent in the deeper earth. The remaining 40 percent returns to the sky through evapotranspiration, the evaporation and transpiration of plant life.
But it doesn’t happen this way in the big city where 55 percent of rainfall flows as runoff bringing with it trash and other pollutants. In places where huge parts of the area have impervious cover, only 15 percent of storm water falls to the earth while 30 percent returns to the sky via evapotranspiration. This is why a storm water pollution prevention plan is usually required in urban areas.
The volume of water isn’t just the only problem with storm water runoff in urban areas; pollution is also taken into account. Without a proper storm water pollution prevention plan in place, the runoff flowing to water systems becomes filled with urban waste. This is the case for tributaries near the world’s densest cities; bodies of water have become polluted with no concrete pollution prevention plans. This consequence compels local governments to require strict storm water compliance in construction sites.
For more information about storm water prevention plan, visit the EPA website at EPA.gov. You can also enroll in storm water training courses which will certify you to prepare Storm Water Pollution Prevention Plans, and to implement and inspect construction sites for storm water compliance.
Urban Development Yields More Storm Water, EPA Says