Since floods can take place on a massive scale, it may be difficult to trace how the choices we make on our own land can contribute to flooding. However, owning land means having a relationship to rainwater flow; “Everyone lives in a watershed,” as the saying goes.
Making a difference in mitigating local flooding or a massive Mississippi River flood is not exclusive to large agricultural areas. With the continual expansion of urban centers into rural areas, so too has followed the increase of impermeable surfaces and lawns.
Exchanging a forest, prairie or wetland for an urban center has an immediate impact on how water moves through our communities: water rolls fast from driveways, sidewalks, across lawns, and into stormwater drains, which prevent the water from percolating into the ground. Soon, ditches, roadsides, and street intersections are flooded due to the inundation of the stormwater systems. Imagine this in every city and town within the watershed, and you have a sizeable contribution to the flooding of the Mississippi River.
“The Primacy of Water” is a concept in Restoration Ecology that views water as the chief ecosystem engineer, and also the most important element to consider when working in the landscape. Water is a master cleanser, washing away anything easily soluble and flushing litter downstream. Any product you use outdoors will likely be rinsed right into the nearest storm drain. Therefore, when excess fertilizers, pesticides or herbicides are used on a lawn, that excess flows into stormwater systems, and ultimately into natural areas like streams and rivers. The same goes for any liquid that leaks from an automobile, a/c, or any other outdoor appliance. Many of these substances are harmful and toxic, like heavy metals and petrol-chemicals, and can persist in the environment for many years. We can cultivate an awareness of the right ways to utilize products like these in order to prevent any negative influence on flooding and water quality and perhaps even make a positive impact.
Home owners and land owners are in an opportune position to reduce the impact their land has on flooding and improve water quality. There are many water management tools and techniques one can employ which are considered Best Management Practices (or BMP’s).
- Increase land covered by plantings – especially native plants.
Plant cover increases infiltration of rainwater into the ground. Native plants require less care, have deeper roots than traditional grass and support wildlife.
- Plant or preserve trees. Imagine a raindrop forming in the sky, then falling multiple miles, crashing against the earth. Now one raindrop may not seem like a lot, but when you have a whole sky-full of them in a large rain event, the effect is compounded. The collision of these raindrops can dislodge soil particles, splashing them everywhere, leading to erosion. When trees are left present in the landscape, and allowed to grow tall, their multi-layered canopies act as shock absorbers to the fast falling raindrops, and help slow the infiltration rate of stormwater.
- Let it Be – Leave things like lawn clippings, leaves and debris on your lawn. Usually seen as refuse – these natural materials are intrinsically linked to the replenishment of nutrients, protect the soil itself, as well as slow down water to better infiltrate soil and retain water. When organic matter residue is left on the soil surface it shields the vulnerable top layer of soil and it even requires less work on our part to allow this to happen, making it truly sustainable.
- Keep rain in Rain barrels for later use! Looking at the ways we build our environment, water can be harvested right from the gutters of the roof. A rain barrel is a popular way to store water for later, and consists of funneling your gutter so that it fills a barrel with the rainwater.
- Plant a rain garden. Rain gardens are typically placed in a lower section of the property that receives more water than average. A rain garden is a depression in the ground that employs native plants to help absorb rainwater and enhance the landscape.
- Use swales to hold and transport water. Swales are swell mini ditches that move water across the contours of a landscape and allow time for it to penetrate the ground. They can be made at any size/scale based on the context and setting and are considered a passive form of catchment because it requires no active maintenance or energy input once installed.
- Use permeable pavement or pavers in landscaping. You can create nice walkways or boarders with hardscaping that will allow the movement of stormwater through the surface.
Clearly, there is much to be aware of when it comes to the effects of water and rainfall, and how it relates to the land around you. However, we can observe most of these design principles in nature’s kingdom. Mother Nature abhors bare soil and monocultures, so if you look to the nearest wild areas for an example, these things will rarely be found. What can be found though is a natural inclination for physical systems to hold onto water for as long as possible, thereby reaping the rewards water has to give. If we follow the age-old examples found in nature, we are sure to be a shining representative of our watershed, and our way to mitigating floods of the Mighty Mississippi!