The Baihly Woodlands neighborhood, located atop a hill in southwest Rochester, was originally developed in the 1980s, an era when stormwater regulations focused primarily on managing discharge volumes, not long-term performance or water quality. The neighborhood’s system relied on stormwater ponds designed to control peak runoff. But after more than two decades of sediment buildup and deteriorated outlet control structures, significant challenges emerged.
These aging systems contributed to frequent ravine erosion downstream of the ponds and recurring flooding in lower-elevation residential areas, issues made worse by recent trends in rainfall intensity and volume. As storms became more severe, the inadequacies of the existing infrastructure became impossible to ignore.
Hydrologic Modeling & Resident Engagement
SRF was engaged by the City of Rochester to perform a comprehensive feasibility study to identify the root causes of the flooding and design solutions. The team conducted an extensive forensic analysis of the site, including direct engagement with nearby residents, to document conditions following storm events. This local knowledge was invaluable in calibrating and validating an XP-SWMM hydrologic model of the system.
Soil sampling was also conducted throughout the site and compared against disposal regulations to help guide construction and environmental decisions.
Solutions that Balance Capacity & Resilience
Multiple alternatives were evaluated, with the preferred solution combining several key improvements:
- Maintenance dredging and sediment removal from the existing stormwater ponds
- Reconstruction of outlet control structures to better utilize storage volume
- Strategic modifications to the trunk storm sewer system to eliminate localized flooding near homes without increasing downstream peak flows
This approach reduced risk while maximizing the effectiveness of existing infrastructure.
Construction Documents & Project Outcomes
SRF prepared detailed construction documents that supported a phased construction option to maximize funding flexibility. Ultimately, the City moved forward with full implementation in a single construction phase. The results were immediate and measurable:
- Flooding in vulnerable areas has been eliminated
- Downstream ravines have been stabilized
- The system has successfully weathered multiple high-intensity storm events without incident
This project demonstrates how targeted upgrades and modern hydrologic modeling can revitalize aging infrastructure and protect neighborhoods from future stormwater threats.
Resource Links:
City of Rochester Public Works Department
Minnesota Pollution Control Agency – Stormwater
Internal Categories:
Water & Environment
Resilience & Sustainability
Municipal Engineering & Utilities
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