Design Basis for Sediment Fence Erosion Protection in New Mexic

The purpose of this thesis is to investigate sediment fence emplacements across New Mexico and recommend desirable conditions and configurations for employing this form of erosion protection. Sediment fence is a form of permeable, spur-type streambank protection used for inducing deposition in sandy arroyos. When used effectively, a sediment fence can force the channel away from a threatened facility by increasing the flow resistance along the undesirable flow path and forcing deposition at that location.;This design basis is formulated from a review of existing design guidance for spur-type erosion protection, field monitoring of a recently installed sediment fence system at Salt Water Wash in Gallup, NM, hydrologic and hydraulic modeling, and visits to six additional sediment fence emplacements across New Mexico. The site at Salt Water Wash was extensively monitored over the summer of 2017 for sediment deposition, vertical stability, and visual assessment of the system performance. Hydrologic modeling of this watershed was performed using HEC-HMS and hydraulic modeling of the sediment fence was performed with HEC-RAS. Additional sites visits to sediment fence emplacements in Blanco, Cuba, and Zia, New Mexico were used to compare and contrast different construction methods and performance on different watercourses. Results of field investigations and modeling indicated that sediment fence is effective in providing bank protection immediately following installation and does not need to reach a point of equilibrium in order to be protective.;General site selection, allowable channel contraction, spur orientation, layering and spacing, and spur length are recommendations made within this design basis. Additional design and construction guidance are provided as appendices as is the project management plan, including project specifications and cost data, and standard details for designing of this form of erosion protection.;Sediment fence provides a viable option for erosion protection methods and should be considered when selecting a method for streambank stabilization. This system is readily available, economic, and effective in protecting threatened facilities when properly designed, constructed, and maintained.