Flooding

Flood Management Risk Tools & Flood Sensors

Technical Resources

Charlotte-Mecklenburg Storm Water Services (CMSWS) is excited for the opportunity to partner with the Department of Homeland Security Science & Technology Directorate (DHS S&T) to develop and test additional resilience tools at the local level. Charlotte is an urban environment where these enhancements can be researched, developed and tested within existing systems. This is a unique opportunity to leverage existing system of USGS stream gages, data, and technology that could be effectively shared with other communities.

Resources for Interested Communities

Charlotte-Mecklenburg Storm Water Services (CMSWS) entered a partnership with the United States Department of Home Land Security Science & Technology Directorate (DHS S&T) in 2018 to help protect the country by researching and organizing scientific, engineering and technological resources. The goal was to design technology to reduce fatalities from flooding events, reduce property losses from future flood events, support community flood resiliency, and to provide flood predictive analytic tools for FEMA and other stakeholders.

Flood Risk Management Survey

The scope of this project was to investigate 1) community-level flood risk and reduction planning tools and methodologies and 2) low cost flood sensors integration with local flood information and notification systems, in an efficient, uniform, reproducible, and cost-effective way. Communities throughout the US are looking for ways to become more resilient and sustainable. Completing a property-specific flood risk assessment is one way to enhance flood resilience. Charlotte-Mecklenburg Storm Water Services (CMSWS) has an existing Flood Risk Assessment and Risk Reduction (RARR) Plan. The plan exists in a dynamic digital environment. The RARR tool uses flood risk data to help identify, communicate, and reduce flood risk at the individual property level in Charlotte-Mecklenburg floodplains.

Flood Management Risk Tool Assessment:

The project team examined flood risk and reduction methods in order to strengthen community resilience including enhancements to the CMSWS flood Risk Assessment and Reduction Tool (RARR). The technical concept of the RARR Plan includes three components that are combined to rank and prioritize mitigation activities. These components are:

Flood Risk Property Score
Risk Reduction Recommendations
Mitigation Priority Scores

Flood Management Risk Tool Development

This effort built upon the detailed approach conducted in the base year, refined the tool to enhance functionality and further documented the approach used to develop the tool to be shared with DHS S&T and interested communities.

Flood Sensor Integration and Installation

Storm Water Services integrated the low cost flood sensors into the Flood Information Notification System (FINS) based on the deployment plan. This task included activities such as installation of the sensors, explore rapid deployment plan for significant events, quality assessment and quality testing of the sensors deployed, performance evaluation and analysis of the sensors, and alerts for First responders.

CMSWS developed an implementation and deployment plan for deploying low-cost flood sensors in an urban environment within the existing FINS, which relies on communications from field gage data for automated flood monitoring and alert notification. Low-cost flood sensors obtained by CMSWS and were integrated into the FINS network. All data reporting capabilities for each sensor type were tested with a focus on data quality, data reporting capacity, sensor reporting interference, and sensor calibration. CMSWS focused on methods to receive, store, and disseminate sensor data using proprietary and publicly available software packages.

Flood Sensor Deployment Plan (42 MB) (This link may take a minute to load.)
Low-Cost Flood Sensor: Urban Installation Guide Book
New Guidebooks Help Urban Communities Install Feature Article

Flood Inundation Mapping

Using historical records in combination with available stream sensor technology, CMSWS produces Flood Inundation Maps during a heavy rainfall event to indicating extent of flooding, depth of floodwater and properties affected. Emergency responders track flood water almost real-time to make decisions to save lives and property from rising water. Knowing the extent of the flooding help the community identify at-risk areas and place resources to those locations.

Using more then 130 USGS Stream Gages and Low-Cost Flood Sensors, CMSWS gathers data for a large portion of the FEMA Regulated Streams throughout Mecklenburg County.

Recent heavy rain event November 12, 2020

Losses Avoided

Mecklenburg County Storm Water Services operates a very aggressive Flood Mitigation Program which is well known throughout the country. Through our buyout program CMSWS has removed more than 450 high-risk homes and businesses once located in the floodplain.

Over 700 families have been removed to a less vulnerable location
185 acres of public space has been left undeveloped to allow the floodplain during heavy rain Storm Water Services estimates the buyouts have avoided more than $30 million in losses
Future savings projected to reach over $300 million

Losses Avoided during November 12, 2020 rain event


Doral/Cavalier Apartments before buyout.	Same area after buyout with buildings removed.

During the November 12, 2020 flood event, Doral and Cavalier
Apartments would have experienced flooding if not for the County Buyout Program.

Flood Sensor Communication, Automation and Display

CMSWS provided research expertise on communication, automation, and display of data originating from the low-cost flood sensors into the Flood Information Notification System (FINS). The task included activities such sensor communication research and automated integration and display of the sensor data into the flood risk management tools (RARR).

Sensor communication research

Communication portability. Explore the ability of the low-cost flood sensors to communicate with other systems and technologies.
Communication with other systems (FIMAN, etc). Work with the State of North Carolina to determine if data from the low-cost sensors can be integrated into the FIMAN (Flood Inundation Mapping and Alert Network) network.
Direct to cell notifications. Investigate the possibility of notification sent directly to citizens with cellular telephones in specific area around a low-cost sensor.
Tie to public Emergency Management systems. Determine if low-cost sensors can be directly tied to existing EM notification systems like “Char-Meck Alerts”.
Other communication options. Investigate the use of other platforms, such as social media, for communicating sensor data and alerts.