COLUMBIA — Accra, the capital city of Ghana, and Columbia have more in common than you might expect. Both were devastated by major flood disasters in 2015 . They receive similar amounts of rainfall every year.
Rapid development is replacing green space with concrete, exacerbating flooding issues. And they have maintained a diplomatic relationship as "sister cities" since 2011, in part to exchange ideas and discuss ways to better manage their stormwater problems. Additionally, green infrastructure like bioswales, rain gardens and other natural drainage solutions have been recommended to both cities as an efficient and increasingly popular method for cities to prevent flooding.
Columbia officials met with Accra leaders most recently in July. Though stormwater and flooding wasn’t on the agenda, the city is interested in having that conversation given the similarities, according to Payton Lang, the mayor’s spokesperson. Less green and more gray brings several problems with cities, one of the most notable being more runoff.
Traditional stormwater is typically worse for the surrounding environment than what's sometimes referred to as green infrastructure. Examples of such infrastructure include bioswales, or vegetated ditches, along roadways and parking lots; rain gardens, low-lying grassy areas that can collect rainwater from a roof or concrete surface; and planters with trees and vegetation. Cities that implement such infrastructure to a large degree are sometimes referred .