Example: Mullins Creek Before
The design approach for Tanglewood Branch utilizes natural channel design principles and is based on on-site existing fluvial geomorphologic conditions data. The techniques proposed in this design plan will help to further stabilize and beautify the stream. A similarly scoped project was implemented on Mullins Creek that runs through the University of Arkansas’ campus. See Example: Mullins Creek Before and After in Fayetteville. Mullins Creek is a small urban creek that has had comparable changes in watershed development, land use, and channel evolution as Tanglewood Branch. Before restoration, Mullins Creek had sections of
Example: Mullins Creek After
channel that had developed into an over widened Rosgen “F-type” stream that was restored into a Rosgen “B-type” stream. The three major techniques that were utilized in restoring Tanglewood Branch are channel shaping and sloping, the addition of grade control structures, and stacked rock walls to protect exposed streambanks.
Throughout the restoration reach, banks were shaped to create bankfull benches and inner berms to allow high flow waters space to spread out to lower stream velocity and shear stresses near the streambanks. The bench elevations were based on surveyed geomorphic features found on site. Rebuilt banks have erosion control fabric mattresses installed and filled with top soil to provide a medium for the native vegetation to grow. The erosion control fabric holds the soil and gravel fill in place for several years and will eventually biodegrade over time. Some of the high terrace floodplains were also graded and replanted with native trees, shrubs, grasses, and flowers.
Grade control structures were installed through the reach to maintain pool depth, riffle slopes, and provide aquatic and terrestrial habitat throughout the year. The structures were built with medium to large boulders mechanically placed to maintain elevations of bed features through the stream. Rock structures help to dissipate excess stream energy and concentrate flows away from sensitive streambanks.
Additional Project Photos