Effects of urbanization on stream channel morpology, Madisonville, Texas

Abstract

This thesis investigates the effects of urban development on two small streams near Madisonville, Texas. One stream is natural and used as a control against which Town Branch, the urbanized stream, is compared. Changes in width, depth, and channel capacity with drainage are evaluated for both creeks. When compared with the natural stream, the urbanized stream shows a complex response characterized by changes in capacity, width, and depth that are different from expected. These differences reflect the influences of urban features including earthen impoundments, concrete bank reinforcements, and encroachment of urban development. Channel capacities are larger than expected in the headwaters of the urbanized creek, but decreases through the urban area, before resuming a more natural trend in the lower reaches toward the basin outlet. Sediment analysis reveals possible disturbance of the natural trend due to urbanization. Overall, the results of this research show that channel responses to urbanization are spatially varied in Town Branch. These findings suggest that the management of urban channels needs to consider spatially distributed responses in the area around Madisonville, Texas, and elsewhere.