BOOM! GOES THE ATMOSPHERE: FIXING OUR AGING STORMWATER INFRASTRUCTURE REQUIRES INNOVATIVE SOLUTIONS
Regardless of whether you believe the science, it’s becoming quite evident that ongoing urbanization and more frequent—and more intense—storms are hitting our cities on a regular basis, increasing stormwater runoff and severely stressing our stormwater infrastructure. Yet our infrastructure is not ready to handle standard, day-to-day uses, let alone impacts from rising sea levels and a changing climate. Right now, cities and towns located along tidal waterways do not have sufficient capacity to convey stormwater runoff even at low tide. Add to that an increase in heavy rainfall with a resulting increase in stormwater runoff: while regional averages in precipitation have varied from year to year, overall precipitation averages across the U.S. have increased since 1958. Some areas, like the northeastern U.S., have seen an increase of more than 70%. Highly urbanized areas located along coastal waterways experience the most dramatic impacts from heavier rainfall; with an increase in impervious surfaces, we see an increase in stormwater runoff. That, coupled with tidal fluctuations within low-elevation areas means that runoff cannot be discharged to waterways. Excess runoff causes massive flooding and backups, resulting in contaminated drinking water, limited water supplies, and habitat degradation.
Understanding peak discharge flow resulting from different storm events provides stormwater managers the means by which to evaluate existing infrastructure, design mitigation strategies, and optimize future systems. Cities across the country are beginning to recognize the need for innovation to address the risks our infrastructure faces and are implementing programs to address changing weather patterns and heavier precipitation. The City of Philadelphia, for example, launched Green City, Clean Waters, an ambitious, $2 billion plan to reduce CSOs by 85% and control runoff from 10,000 acres of land across the city over the next 25 years. Programs like this can reduce stormwater runoff and associated damage by the billions of gallons—and billions of dollars—but it is not feasible to replace all of our stormwater infrastructure with GSI. From the Pacific Northwest to the Southeast, cities are experiencing storm events that challenge our aging infrastructure on a regular basis. As a result, we will have little choice but to spend a great deal more money on replacing, upgrading, evaluating, monitoring, and maintaining our stormwater infrastructure, ensuring that it performs as needed and mitigates risks of ongoing CSOs. From where we stand, it seems like nowis the time to start gathering the data we need to optimize our infrastructure, as well as the spend.