This project addresses chronic flooding and drainage challenges across a 12‑square‑mile portion of the Cal‑Sag Watershed in southern Cook County. Our team is providing engineering services to develop a comprehensive stormwater study and master plan for five interconnected sub‑watersheds, with the objective of achieving 100‑year flood protection for all structures, including basements. The effort builds upon prior watershed studies to validate existing findings, evaluate current system limitations, and identify implementable solutions that improve flood resilience at both the regional and neighborhood scale.

KEY CONTRIBUTIONS:

Watershed Modeling & Analysis
We developed conceptual hydraulic models using HEC‑RAS and XP‑SWMM to evaluate flooding behavior across multiple sub‑watersheds, including complex flow interactions between the Lucas Ditch and Lucas Diversion Ditch during major storm events.

Evaluation of Existing Conditions
Our team reviewed and validated prior studies, then expanded the analysis to address undersized storm sewers, limited conveyance capacity, and insufficient storage throughout the drainage area.

Flood Mitigation Alternatives
We identified a range of improvement strategies, combining traditional infrastructure solutions with planning‑based approaches to increase storage, reduce flood risk, and improve system performance.

Private‑Property & Redevelopment Strategies
We evaluated flood mitigation opportunities on private property, including residential green infrastructure, underground storage on commercial and institutional sites, and redevelopment of vacant or underutilized parcels to create additional flood storage.

Public Engagement Support
We supported community outreach efforts focused on educating stakeholders and encouraging participation in flood mitigation through green infrastructure and private‑property improvements.