Unveiling the hydrologic climate resilience of Blue Green Infrastructure: Do we have our design/modelling numbers right?

As precipitation patterns change, so does the need for revised Blue-Green Infrastructure (BGI) design standards. Holistic hydrologic design and modelling are vital for addressing climate uncertainties and ensuring the long-term integrity of optimized BGI. Within that scope, two key design needs are what size storm event needs to be safely routed through a BGI practice, and what is the precipitation depth of a Water Quality (WQ) event? WQ events principally determine the surface area and storage depths of BGI. The investigation uses North Carolina, USA, as a case study to determine revised design standards for these hydrologic parameters. Of particular interest was the increase, usually substantially (up to 25%), required for the WQ event depth when focusing on the most recent decade of available precipitation data. These results will be used to inform design standards in NC, likely yielding larger, and more protective, BGI in the coming years.