Let's Work with Nature to Help Prevent Urban Flooding

Let's Work with Nature to Help Prevent Urban Flooding

As a former flood adjuster I saw the wrath of what flooding has done across our nation. I learned how destructive and devastating flooding can be and how critical it is to take steps to protect ourselves from its effects.

Many are of the opinion that we're fighting a losing battle with nature. I felt the same way until I discovered that there is hope in working with nature.

Cultures around the world have dealt with flooding for centuries but it's getting more severe due to 2 main issues: increasing population growth and poor building/material designs.

As urban populations grow, more land is developed to accommodate them, which in turn disrupts natural water flow and absorption within the ground. More specifically, cities have chosen to build with non-permeable materials on our roadways, in our yards and on our roofs. What once naturally was absorbed by the soil is now being diverted off the roof, across the yard, down the driveway and onto our roadways.

Here are a few simple ways in which we can change the current system and begin to embrace a more sustainable, natural system:

1. Design roofs with water harvesting in mind over water displacement.

Let's start with the roof because it is usually here that drainage issues begin. The steeper your roof is, the faster and more violently water is displaced onto the ground. We can combat this with green or blue-green roofs which allow water to absorb into a soil-like material where water-loving plants can utilize this much needed water to thrive. The soil-like material on the roof acts as an insulation layer keeping the home cooler in the summer and warmer in the winter months. Plants then absorb the water and expel it, akin to how our skin cools our bodies through perspiration. During the summer, this process helps to cool the extreme heat surrounding your home. Once it hits the roof, rain water is dramatically slowed down, absorbed by plants, filtered, and then returned to the ground at a more natural rate. As a result, gutters and downspouts function better and can more easily transport this excess water to water harvesting tanks. This excess water can then be used as needed at a later date.

2. Design landscapes with more emphasis on plants rather than sod.

Since the late 1800s, we Americans have had a rather strange love affair with our lawns. We show off how green and nicely trimmed they are by flexing on our neighbors with loud and industrious "trimming" equipment. We apply toxic fertilizers and insect repellants at will to keep them green and bug free. We then use unsustainable sprinkler systems to flush it all away back into our drainage systems where this water ends up "clean and recycled". But this is no modern love affair. Humans have been embracing low-cut savannah style landscapes for centuries now. As a result of the removal of trees, our ancient ancestors could now see predators approaching and defend them before it was too late. Now we see the lawn as a status symbol and if you don't keep it up, the neighbors will start to gossip and ban you from the so-called neighborly "tribe". In spite of this long history of boring mono-lawns, we have found that the lawn does next to no good for wildlife ecosystems, and that its absorption abilities are also very poor. Instead, it helps to have plants that establish large deep root systems. These root systems give structure to the soil. This soil structure allows water to easily enter and travel down to where the roots are growing. Some native grasses even have roots that grow up to 12' beneath the ground! Most grass species we use for modern day lawns have quite the opposite root structure and often only root a few inches beneath the soil surface. These soils become more compact over time and become better at diverting water than absorbing it.

3. Do we really need concrete, let alone asphalt driveways?

One of the most unsustainable materials we have today would have to be concrete. Concrete is made from a mix of Portland cement, water and aggregates like crushed stone and sand. But what is Portland cement and where does it come from? Portland cement is a mixture of limestone (ground to a fine powder after being treated in a kiln) and gypsum powder. Gypsum powder and limestone are both mined from the ground and are non-renewable resources that are being extracted from the earth for the sole purpose of automobile parking. After concrete hardens, it becomes impermeable and aids in water shedding from the property into the streets where this sheer water run-off enters our faulty modern day drainage systems which are overrun and in desperate need of a break. Asphalt driveways have their own issues. Asphalt is a petroleum-based product and as water travels over the surface, so do particles of oil and petroleum which end up in our drainage system as well. Instead of using solid concrete pads a much better use of concrete is crushed or recycled concrete gravel. This way we are re-using a non-renewable resource and gaining better drainage qualities from the more permeable material. Another option is to use hollow pavers embetted in the ground where foliage can grow in between and increase soil structure. In summary, these issues are only my point of view based on my time spent helping homeowners during Hurricane Harvey. I also saw first hand folks in neighborhoods like those in Texas and around the country with similiar problems. I believe this is the start of a future where design is based on how our homes will impact our neighbors and our overall communities at large.

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