As with desertification, the core concept of “stormwater management” is clear from its name. It’s the idea that after rain, especially heavy rain, water must go somewhere and through management, humans can decide where that water goes. Of course, before human development of the natural environment or in areas that have experienced substantial development (e.g. building homes, commercial structures, and transportation infrastructure), stormwater “self-manages” through runoff to a waterbody, soaking into and being filtered by the ground, and evaporation back into the atmosphere.
Because human interventions, in particular, the increasing use of impervious surfaces, significantly decrease both vegetation and the ability of rain to infiltrate into the ground, in the built environment, much more runoff is generated than in the undeveloped condition, resulting in flooding and other challenges. Stormwater management was created to solve problems created by human activity. And as with many such well-intended human endeavors, traditional stormwater management approaches bring with them their own troubling unintended consequences.
For instance, in the effort to direct increased runoff away from the built environment and to available water bodies, conveyances such as ditches and storm sewers greatly increase the volume of water in waterways, in turn increasing their power to erode the landscape and cause flooding. To mitigate these issues, still more engineered drainage infrastructure is typically developed (e.g. retention or detention basins, concrete lined channels, culverts, and storm drain systems). As we’re seeing with the spread of desertification discussed previously and the severity of flood events and water pollution within this traditionally-managed stormwater context, the time is ripe for alternative and complimentary approaches to stormwater.
For example, consider what happens when, instead of viewing stormwater as a problem that must be controlled and quickly diverted through costly and imperfect traditional infrastructure projects, it is treated as the invaluable natural resource it is. Typically called green infrastructure, such an approach to stormwater might involve practices like water harvesting for irrigation, use of bioswales (vegetated channels providing filtration and retention of stormwater), development of residential rain gardens, and many other decentralized low-impact and low-cost measures that work with, rather than attempting to control, nature.
But the “green” in green infrastructure is about more than its general environmental-friendliness. The majority of its methods sustain and benefit from an increase in actual greenery. This increased vegetation also provides increased habitat availability for a greater diversity of wildlife, decreases wind and water erosion, mitigates conditions favorable to starting wildfires, and ultimately contributes to reversing desertification.
See the next entry in this series, Reversing desertification through regenerative agriculture and land management, to learn about how agriculture, like infrastructure, can be reoriented to work with, rather than against, nature.