USGS Raleigh Stream Bank Erosion Study

The City of Raleigh partnered with the US Geological Survey (USGS) to complete a Comprehensive Assessment of Streambank Erosion Hotspots in Raleigh, NC project.

This project will predict streambank erosion potential using remotely detected datasets. Results will provide the City with a city-wide dataset of streambank erosion hotspots that can be used to identify areas with severe erosion problems, as well as areas with stable streambanks. This information allows the City to deploy staff for field investigations and prioritize opportunities for stream restoration and stabilization projects. This study informs future watershed strategies and creates a framework for the City's developing Stream and Riparian Program.

Project Details

Type:: Stormwater
Budget:: $394,100
Project Lead:: Stormwater Management
Contractors:: Partnered with USGS

Schedule

DATE	ACTIVITY
2021-2022	GIS Analysis
Fall 2021-Spring 2022	Field Analysis
Fall 2022-Fall 2024	Statistical Analysis and Infrastructure Risk Assessment
2025	Reporting and Publications

The Problem

The City of Raleigh recognizes streambank erosion within the city limits. However, current ways used to locate eroding streambanks, like stream walks or citizen complaints, are inefficient and inconsistent. Streambank erosion is highly variable and difficult to scale rate of erosion from individual measurements. We need new tools to remotely identify streambank erosion hotspots. With these new tools, we can track erosion and deposition over time. Models relating field conditions to lidar-derived topographic data allow for the scaling of site-specific measurements of streambank erosion to the larger stream network (Hopkins et al. 2018).

A review of streambank erosion hotspots throughout the City’s stream network prioritizes future stream mitigation projects, confirming that resources will be used to maximize benefits to stream health, protection of property, and human well-being.

Raleigh Erosion Study Area Map (USGS)

Project Objectives

Generate raster datasets that describe elevation, streambank characteristics, and changes to elevation and streambank characteristics using remotely detected lidar data.
Assess streambank erosion potential in select stream reaches throughout the City of Raleigh using rapid field methods.
Predict streambank erosion potential throughout the Area of Interest (or extent of 2022 lidar collection) using statistical models that relate lidar-derived datasets (Objective 1) to field-based streambank erosion ratings (Objective 2).