Location: Watershed Physical Processes ResearchTitle: Laboratory testing of a model floating breakwater for reducing wave-driven erosion of on-farm reservoir embankments
Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/6/2023
Publication Date: N/A
Interpretive Summary: ABSTRACT ONLY
Technical Abstract: The dependence of the Mississippi Delta region agricultural industry on groundwater is unsustainable as evidenced by groundwater table decline in the Mississippi River Valley. To reduce this demand on groundwater resources, on-farm storage reservoirs have been used to better manage irrigation water. Due to the lack of natural protection, these reservoirs endure largely unabated winds, and the reservoir embankments are damaged by wind-generated waves. This damage results in high maintenance costs over time. It is therefore necessary to identify cost-effective methods of protecting these embankments. Floating breakwaters have been shown to effectively reduce wave impact on offshore and coastal structures, and by identifying a simple, cost-effective design with adequate efficacy, the use of a floating breakwater should reduce the frequency of required maintenance. In this study, the use of a floating pipe breakwater for wave attenuation was investigated. Specifically, an efficient design for the cable mooring system was needed. The proposed breakwater uses HDPE irrigation pipe moored to the reservoir bottom by steel cables. A model breakwater was constructed and tested using multiple mooring configurations subject to variable wave characteristics in a wave tank at the USDA-ARS National Sedimentation Laboratory. Water surface elevations and mooring cable forces were recorded. Tests were also conducted to track the breakwater motions using photogrammetric methods. The associated movement patterns of the wave barrier will be discussed, as well as the results on wave energy reduction in these experiments. The details of a full-scale breakwater for deployment in an active reservoir will also be presented.