Flood Early Warning System

Program

Flooding from extreme rainstorms happens more often now causing safety concerns and property damage. To help with response efforts and to keep people safe, we are working on a pilot program that predicts and helps us prepare for flooding.

Benefits

Notify the public and close roads (as needed) sooner.

How it Works

We're focused on collecting data and using technology to determine:

When streams may flood;
How high floodwaters may get;
How much lead time we have to prepare; and,
What resources are needed.

Data Used

Stream and rain gauges
Gauge-Adjusted Radar Rainfall (GARR)
- Provides real-time data on rainfall amounts across Raleigh.

The dashboard that provides data from the system is for city staff only. You can use this map to track storms with us.

Phases

Phase 1 (Complete)
Forecast flooding in Raleigh along Crabtree Creek between Ebenezer Church Road and US 1.

Phase 2 (Complete)
Forecast flooding in Raleigh along Walnut Creek, Marsh Creek, and the rest of the Crabtree Creek watershed.

During this phase, we also worked with US Geological Survey (USGS) to install rain gauges at fire stations in Raleigh. These gauges collect data every five minutes.

Phase 3 (Ongoing until Dec. 2022)

Expand data collection to more areas known to flood;
Monitor conditions at specific dams in Raleigh;
Develop a web app that simulates and helps predict different types of flooding conditions; and,
Ensure all gauges connect to the latest alert system;
Install a flood monitoring camera at Rose Lane.

Collection Times

A US Geological Survey stream gauge near Walnut Creek — A stream gauge on S. State Street.

Along with USGS, we collect stream gauge data every five and 15 minutes (instead of every hour) at specific locations. We'll see more response times and alerts like this as we launch the program across the city.

Note: We don't receive data right away. There is a brief period from when data is collected to when it's available on our dashboard.

Every Five Minutes
Anderson Drive	Old Wake Forest Road	S. State Street
Buck Jones Road	Pigeon House Branch at Cameron Village	Sunnybrook Road
Highway 70 at Glenwood Ave.	Rocky Branch near Pullen Road	Trailwood Drive

Every 15 Minutes
Ebenezer Church Road	Marsh Creek	S. Wilmington Street
Lake Johnson	Rose Lane	US 1 (Capital Boulevard)

Process

We are working on this program with consultant, Vieux and Associates. The process includes:

Getting details on floodprone areas;
Identifying types of warning alerts;
Recommending flood forecasting for 'hotspot' areas;
Gathering data and modeling stream flow and flooding;
Inventorying and mapping the stormwater system; and,
Setting up, maintaining, and expanding the early warning system to track flooding conditions.