Location: Watershed Physical Processes Research
Project Number: 6060-13000-023-03-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2012
End Date: Dec 1, 2013
The primary objective of this work will be to update NRCS Technical Release No. 56 (TR56) “A Guide for Design and Layout of Vegetative Wave Protection for Earth Dam Embankments” with the results of the USDA-ARS, National Sedimentation Laboratory (NSL), Technical Report No. 65 “Experimental and Numerical Investigations of Floating Breakwater Performance”. The updated material will include guidelines for field implementation of floating wave barriers. A specific objective is to provide additional field data and improve the existing guidelines for sizing and deployment of the floating breakwaters.
The Technical Release No. 56 (TR56) update will include a review of relevant literature describing research conducted since its publication in 1974. The contemporary report will include current methodology for using floating wave barriers and vegetation for levee protection. The new report will summarize the findings of National Sedimentation Laboratory (NSL) Technical Report 65 by using appropriate narrative, plots, and lookup tables. The floating wave barrier work will be summarized and include only information relevant to an engineer seeking to design a wave barrier system. This will include a technique specific to small reservoirs for estimating wave characteristics from wind speed and fetch length. Example calculations for wave barrier design will include wind/wave prediction, barrier sizing, and estimated performance of the wave barrier. It is not anticipated that this update will include comprehensive specific recommendations on materials, connections, etc. The focus will be on the necessary dimensions and buoyancy needed for wave energy reduction. A new field station will be constructed in a selected pond, with cooperation from the NSL, to collect long-term field data, which will include synchronous measurements of wave height, water temperature and wind speed as well as soil type and erosion rate. The new data sets will provide more reliable guidelines on wind-wave prediction in small ponds and begin to relate them with levee erosion rates.