Stormwater Management and Flood Mitigation
Climate Resilience and Adaptation Toolkit
Climate Resilience and Adaptation Toolkit
School campuses contain a significant amount of impervious landscape, such as paved playgrounds, parking lots, plazas, and corridors. These smooth, open surfaces are essential for safety, accessibility, and practicability when it comes to navigating campus and in certain emergencies. However, as California’s school communities have begun experiencing extreme precipitation and storm based flooding as an impact of climate change, they are now experiencing new emergency concerns. From a surface water perspective, all that asphalt and paving can lead to significant runoff when it rains, in particular when there is heavy rain (sometimes referred to as atmospheric rivers or severe storms).
This storm based flooding can have multiple effects on schools, for example:
Flooding can have lasting effects on buildings such as water damage, mold, wood damage due to water, metal corrosion, distortion on walls and floors, water contamination, and the damage of other school supplies such as furniture, computers, files, books, and food;
Flooding can also impact school grounds, where severe wet weather can and poorly draining adjacent roadways can cause delays or even full impediment to accessing school entrances, and ponding onsite can cause disruptions or even safety hazards for students, families and staff;
High winds and heavy rain can affect the power supply systems and electrical systems within schools; and,
During longer periods of drought following warmer and wetter winters, schools can succumb to the impacts of extreme heat and increased pressure on water supplies.
Depending on the severity these impacts can cause short or long-term disruptions for learning due to displacement and other ongoing access issues.
Because storm drain systems are often a separate network of gutters, pipes, and other drainage features that ultimately connect to creeks, rivers, and then bays and oceans without any treatment, schools can end up contributing to broader stormwater management challenges. For example, extra runoff flowing from schools can also add to localized flooding and creek erosion during big storms, and the issue of trash in storm drains can be exacerbated when haphazardly discarded straws, plastic baggies, and other single-use items from school sites are flushed into the storm system.
The good news is that as schools have begun to understand this imperative, more and more school districts have begun to adapt to these challenges. Adaptations usually fall into two different sized stormwater management strategies:
Small Scale Stormwater Capture: rain gardens, cisterns, bioswales, and schoolyard forests
Large Scale Stormwater Capture: subsurface water retention/detention systems that can be used to reduce local flood risk, recharge groundwater, and off-set potable water use for irrigation
In February of 2024, San Diego schools experienced what was once considered once-in-a-generation precipitation and flooding, testing the emergency services response protocols at the County Office and encouraging them to think about long-term prevention and preparedness.
Learn More
Open Door: Preparing for a New Normal: Climate Emergencies and Their Impact on Schools (Watch from 20:17 to 30:29) - (April 2024)
Working with community based partners and technical assistance providers, the San Carlos School District tackled extreme precipitation and storm-based flooding challenges head on, moving from small scale projects such as bioswales and rain barrels to large scale comprehensive resilient schoolyard project planning that includes a proposed field replacement with high efficiency water systems and storage, large rain gardens, tree plantings, and bioretention areas, in addition to safer, more enjoyable play structures and outdoor learning spaces.
Learn More
Spotlight: Stormwater Management through Living Schoolyards - (November 2024)
Explore the data for your region regarding extreme precipitation and stormwater projections, and sea level rise. Note that some counties may include different biomes (coastal, urban, forest, dessert, agricultural lands, etc.) - explore impacts by biome here.
The American Flood Coalition is a nonpartisan group of political, military, business, and local leaders that have come together to drive adaptation to higher seas, stronger storms, and more frequent flooding. The coalition advances solutions that support and protect flood-affected communities
Experiencing or witnessing extreme storms can be traumatic for the children, adolescents, and adults within a school community. It is important to consider how to best integrate trauma informed practices into the phases of emergency preparedness, and to equip classroom educators and administrators with the tools they need to implement trauma informed practices with students and families. Explore resources and implementation tools at the Resource Center for Environmental and Climate Action in Schools.