On Monday September 5, 2022, Rhode Island was stunned by the flash floods following nearly 11 inches of excessive rainfall over much of southern New England. The City of Providence received around 8 inches of rain, which led to the collapse of a building, closure of an interstate highway, displacement of residents, and an undetermined cost in repairs for damage across the city. A letter request from Sen. Jack Reed, on behalf of the state, was sent to the office of President Biden for federal assistance.
As an older New England city, Providence’s stormwater infrastructure’s initial construction started about a century ago. As new development and urbanization continued, natural areas were converted to impervious surfaces and the associated stormwater drainage requirements increased, contributing additional stress on outdated systems. The carrying capacity of the land to absorb stormwater worsened as the threat grew more prevalent. The Providence we know and love today is vulnerable to immense rainfall events in the metro region and storm surge events in the coastal areas. Being located at the bottom of a watershed means the full volume of stormwater runoff for large drainage areas collects in the city’s rivers. In addition to structural impacts, the environmental cost of unmanaged stormwater runoff can contribute to contaminated water from sediments and pollutants, as well as disturbances to ecosystems.
Although the Labor Day storm had been predicted, much of Rhode Island was ill-prepared for the downpour. Systems that were designed based on older design assumptions and flooding projections, do not reflect recent findings that illustrate how susceptible communities like Providence are. Businesses, universities and residents alike are at the mercy of Mother Nature; flooded college dorms, closure of government buildings, submerged vehicles with stranded commuters, were just a few of the impacts on display during Monday’s storm.
The risk of major flooding in Providence has been known for years but action remains incremental. As highlighted in the Providence Resilience Partnership, Towards a Resilient Providence Report, “In 2010 alone, Rhode Island experienced two 100-year (or 1% annual chance) floods, and increased precipitation intensity and frequency from a changing climate will significantly worsen the impact of such incidents. Since 1991, the Northeast has already seen an 8% increase in overall precipitation; since 1930, Rhode Island’s average precipitation has increased by more than 10 inches; and since 1958, the Northeast has experienced a 71% rise in heavy rain events.”
This summer alone has demonstrated how unpredictable current weather patterns can be. In July, Providence had less than half an inch of rainfall- the third driest July on record. Mere weeks later, major highway arteries in the city have been completely shut down – twice – due to extreme precipitation.
As recommended in the Towards Resilient Providence report, “A single, accepted statewide predictive flooding model that incorporates future climate conditions—increased precipitation, coastal and inland flooding, and rising seas—would benefit data-driven investment in more resilient stormwater infrastructure.” With the understanding that vulnerability assessments can take years from design to completion, accelerating climate change requires establishing policies and actions for more frequent assessment, planning, investment for all major infrastructure that sustains community well-being.
Providence was given another wake-up call but the next may not be as forgiving. We MUST act now.
Author: Brandon Haley