A cascading network of decentralized detention-based green/gray infrastructure (DBGI) is demonstrated as a viable alternative to mitigate combined sewer overflows (CSO). DBGIs are strategically placed throughout a sewershed to intercept, temporarily detain, and release rainfall-runoff during and after a storm event. The captured stormwater is released into the existing collection system. The proposed operating plan is "synchronized inhale then exhale strategy" (SITES) where all DBGI fill and empty in unison. A unique desktop framework is developed to demonstrate the concept. Simulation runs show that the DBGI operated with SITES brings the sewershed into compliance with the USEPA CSO control policy.