Testing of a Bank Angle Vs Height Model for Prediction of Urban Creek Slope Failure in the City of Fort Worth

Due to the nearness of development to the edge of urban creeks, creek bank instability not only impacts housing and property values but also threatens roadways and utility line crossings. City of Fort Worth began a GIS mapping effort to protect, educate and assist with development policies to avoid vulnerable creek segments subject to erosive failure. Creek banks can be vulnerable to a variety of failure inducing phenomena ranging from material loss along toe of bank to cohesion loss during saturated flood flow conditions. In this paper, we propose capturing the many phenomena of creek bank failure by using a plot of creek bank angle to bank height to separate stable, at risk and unstable slopes. This plot is tested in the City of Fort Worth based on areas identified from the past mapping efforts and from field observations. Height and slope parameters for the plot were determined from aerial and drone LIDAR measurements.