A looming danger is silently lurking behind outdated infrastructure, inequitable emergency response systems and impervious built environments. For many years, news coverage about climate change has omitted the crude reality about the lack of preparedness for the myriad of challenges a changing climate could present. In Stockton, the atmospheric rivers from earlier this year led to numerous cases of inner city flooding with little to no warning, oversight or help from city officials and FEMA. As winter sets in, now is the time for city officials to take action, prepare residents and adapt to our changing environment by implementing proven engineered solutions, namely stormwater capture systems, permeable surfaces, and redesigning levees.
As climate change continues to impact our aging infrastructure through extreme weather events it is imperative that we prioritize vulnerable and at risk communities that have been directly exposed to environmental hazards and historically marginalized from flood protection funding. “Societies don’t allocate environmental risk equally, often making the poorest communities the weakest links in hazard mitigation” (Cutter et al. 2003; Godschalk 2003; Tobin and Whiteford 2002). This is the case throughout California in environmental justice communities like Springville, Tulare, Pajaro, Merced and Stockton.
The significant change in climate and the hydrologic cycle since stormwater capture systems were built in the 1960s, has rendered the current systems inadequate to handle extreme weather events such as atmospheric rivers. This thereby introduces many infrastructure challenges such as inner-city flooding and backed up stormwater capture systems exacerbated by a lack of permeable surfaces which can act as natural drainage pathways or urban sponges. The location of Stockton in the lower point of the San Joaquin Valley basin complicates the flood risk since when flood water flows, it will flow down the path of least resistance and directly into Stockton. The San Joaquin Valley experiences high groundwater table levels which results in recurring basement flooding, street flooding and other flooding events when there is excess precipitation and runoff.
If a flooding event would occur today it would cause $1 trillion dollars of damage. Permeable surfaces can be adapted to existing infrastructure to provide many benefits including safe roads, sidewalks, and urban green spaces. As rain percolates into the water table to replenish groundwater, stormwater capture systems are relieved of excess water runoff. Additionally, bioswales can be utilized in inner-city medians and sidewalks to allow infiltration and at the same time deter freight trucks from driving through residential neighborhoods. An increase of permeable surfaces, robust stormwater capture systems and urban resilience measures such as utilizing permeable pavement, bioswales, and urban ecosystems must be considered and implemented. These flood mitigation efforts all function in tandem to protect the lives and public health of the residents in Stockton.
Although levees are a widely recognized engineered flood protection method from high flow and precipitation events not the only way to mitigate flood risk, provide flood resilience and protect vulnerable communities. High flow events are an imminent concern due to the Sierra Nevadas experiencing a historic snowpack. The continuous atmospheric rivers of 2023 set forth an unprecedented start to the 2024 water year. When the Sierra Nevada snowpack eventually melts and drains into the Sierra Nevada foothills, it has the potential to overwhelm our current infrastructure as seen with the reforming of Tulare Lake.
Permeable surfaces throughout cities, improved urban green infrastructure and natural drainage systems can help protect the lives of vulnerable populations across the San Joaquin Valley and California. Floodplains such as the Van Buskirk project are necessary for the adaptation of our built environments. With our changing hydrologic cycle, it is only a matter of time before our flood protection systems as they exist today will be obsolete. Cities across the state and nation must start implementing resilience measures to best ensure public safety. Restoration of flood plains, revitalization of urban green spaces and implementation of permeable surfaces are holistic solutions to a rapidly changing climate.
By, Alejandra Amador-Caro, a recent graduate from UC Berkeley, I received my BS in Civil Engineering with an emphasis in Environmental Engineering. I was part of Professor Tina Chow’s research team through UC Berkeley’s The Green Initiative Fund for the past year collaborating with Tanisha Raj and Ector Olivares from the Environmental Justice branch at Catholic Charities Diocese of Stockton.