STORMWATER SERVICES

Flood Mitigation Analysis

M3 Engineering is helping to analyze the flooding issues for a Chicago suburb and to develop potential solutions to help alleviate the problem.  The Village of Harwood Heights, IL has suffered from frequent and extensive flooding that has inundated the streets and caused damage to buildings.  M3 is using XP-SWMM hydrologic model to determine the root causes of flooding, as well as Optimatics optimization software to identify the most cost-effective solutions.  Potential causes include tailwater effects from the downstream transmission system, undersized collection systems and inadequate inlet capacity on the residential streets.  Solutions that are being studied include surface and subsurface storage, green infrastructure and collection...

Comprehensive Stormwater Master Plan

M3 Engineering performed a Comprehensive Stormwater Master Plan and an economic analysis for 20 square miles in the City of St. Charles, MO. The purpose of the study was to recommend flood mitigation measures, prioritize stream restoration and determine whether there are steps the City can take to improve water quality in streams. FLOOD MITIGATION - The Flood Mitigation effort began with a review of flood complaints and a field inventory of structures known to flood. GIS and XP-SWMM was used to model both the open channel and enclosed systems in order to identify the root causes of flooding and to model alternatives to mitigate it. A risk-based analysis is being used to determine the level of improvement that is consistent with the...

Bridle Spur Culvert

An existing 785-foot Corrugated Metal Pipe (CMP) culvert, with a diameter ranging from 66” to 102”, was suffering from severe degradation. The culvert flowline was rusted through for much of the length, and the entrance was damaged during a heavy rain event, requiring an emergency repair. There were also reports of increased upstream flooding following the repairs. M3 was retained to address the degradation, flooding and the damage sustained by the culvert. M3 first performed a field condition assessment and found the existing CMP culvert to be “fully deteriorated”, which implies a high risk of structural failure. Any rehabilitation alternative needs to assume the existing culvert has no remaining structural capacity. M3 then prepared...

Force Main Condition Assessment and Rehabilitation

After complaints of flooding along Essex Creek, a tributary to Midland Creek in Maryland Heights, MO, the City decided to investigate what measures could be taken to reduce the flooding. M3 Engineering performed the hydrologic analysis, along with a geomorphic investigation of the stream. In order to determine the most cost-effective solution for the City, M3 Engineering Group performed a risk-based analysis that defined the financial impact of flood damage for various frequency events versus the cost of constructing improvements that would reduce or eliminate the flooding. Improvements that were considered include enlarging stream crossings and widening the stream cross section of Essex Creek, as well as the downstream Midland Creek....

Cole Creek Flood Reduction

M3 Engineering performed an alternatives analysis and design to alleviate flooding of residential and apartment structures along several miles of Cole Creek Cole in the City of St. Charles, MO. Residents along Cole Creek have suffered from flooding for several years, so the City committed to implementing a multifaceted project to address the situation. Using XP-SWMM to model the open and enclosed storm systems, M3 determined that the root cause of the flooding includes undersized bridges, a lack of stream capacity and houses that were simply built within the floodplain. The preferred flood reduction solution included: replacing a Norfolk Southern Bridge; replacing two vehicular bridges; converting a sludge basin to a storage basin;...