The Greening of an Urban Right-of-Way: Combined Sewer Overflow Control Implementation in Peoria, IL

Abstract Submission: Peoria, Illinois is among the number of cities across the U.S. that operate a combined sewer system. Since 2020, the City and the Greater Peoria Sanitary District have been actively responding to a consent decree requiring more robust control of the combined sewer overflow (CSO). Green Infrastructure (GI), promising cost savings and desirable co-benefits, was identified early as a preferred way to augment needed CSO controls – in addition to expanding system capacity through in-system and offline storage. Constraints of an urban sewer retrofit include the choice to place GI measures exclusively on public property, in the right of way wherever possible. The five-year construction plan began in 2022. Issues with early-stage-implemented GI measures became apparent almost immediately, the acknowledgment of which has paused new GI construction as the City and its designers reconsider the design and construction choices and timeline. As GI measures to address the needs of urban stormwater networks has developed in recent decades from innovative experiments to a well-studied and -practiced area of design engineering, examples abound and can provide lessons for the situation in Peoria. Similarly, the nexus of constraints in Peoria presents a unique opportunity to examine what GI practices can be optimized to make the addition of CSO control measures more feasible for small and mid-sized urban centers. The present research begins by investigating the problems facing Peoria’s initial attempts at CSO control through implementation of GI measures and moves subsequently into a rigorous, focused assessment of the models, examples and literature that can inform the use of GI to address stormwater and CSO control in the right of way of urban locales of modest means. The thorough assessment of available practices culminates with recommendations for the ongoing CSO control efforts of the City of Peoria and the Greater Peoria Sanitary District.

Learning Objectives/Expected Outcome (Optional) : Introduction to Green Infrastructure practices;
State of the art update for Low Impact Development of Green Stormwater Infrastructure;
Green Infrastructure in the Right of Way;
Optimization of GI measure selection for small and midsized cities.