When rain falls on forests, grass, and mountains, the soil soaks it up. Plant roots hold the soil in place, and the rainwater filters slowly to enter streams, creeks, and rivers. But for over a century, we’ve developed land in a way that interrupts the natural water cycle. Paved surfaces and hard rooftops give rainwater nowhere to go. Instead of filtering slowly, stormwater runoff rushes downhill or pools in low-lying areas, carrying pollution it picks up along the way. The impacts include flooding in denser communities, sewage overflows, and an expensive, growing network of pipes, pumps and other infrastructure designed to channel excess rainfall and send it directly into the nearest creek, river or lake.
The rain has to go somewhere, and piping it away isn’t a viable long-term solution. Heavy rain quickly overwhelms even the best network of storm drains and stormwater outfalls. Development in urban areas can cover as much as 99% of the land with pavement. As our cities grow, it is essential that we incorporate green solutions to protect against catastrophic urban flooding and prevent pollution.
Low-impact development (LID) is an alternative to sending stormwater runoff directly into waterways like Puget Sound. LID strategies, such as green roofs, permeable pavements, and rain gardens, use or mimic natural processes to collect and filter stormwater runoff before it can reach our waterways. LID manages the flow of stormwater and filters out pollutants, protecting people, water quality and aquatic habitat from pollution and flooding.
Stormwater retrofits correct and upgrade existing development to meet today’s standards for protecting water quality. This means addressing areas that were developed before current stormwater permits and water quality protections were enacted to ensure that our cities and counties are treating as much stormwater as possible. Stormwater retrofits are critical to protecting Puget Sound as our communities grow.