Adapting Permeable Reactive Barriers for Surface Application and Developing Novel Soil Amendments for Post-Wildfire Runoff Mitigation

Post-wildfire rain events can generate significant runoff due to reduced ground cover and the formation of a hydrophobic soil layer, leading to flash floods that threaten downstream infrastructure and degrade water quality. To address these challenges, we developed two novel mitigation technologies: Surface-Level Permeable Reactive Barriers (SLBs) for immediate flow reduction and water quality improvement, and CoverBombs for long-term soil remediation, infiltration, and watershed recovery. While testing was conducted under controlled conditions, design parameters were informed by slope and spacing conditions from Cuesta Ridge in San Luis Obispo, California. SLBs reduced runoff velocity by 82.6%, total suspended solids by 97.9%, and turbidity by 95.7%, while CoverBombs improved infiltration by up to 10.55 times within 18 days. Together, these tools offer a scalable and low-impact solution for enhancing post-fire watershed resilience.