Initial Morphologic Evolution of Perdido Key Berm Nourishment, Florida
ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
Pagination or Media Count:
This Coastal and Hydraulics Engineering Technical Note CHETN documents the initial morphologic evolution of the Perdido Key, FL, swash-zone berm based on beach-nearshore profile, sediment samples, and nearshore wave data collected during the first six months after berm construction. The US Army Corps of Engineers USACE, Mobile District, dredged the navigation channel at Pensacola Pass, FL, from November 2011 to January 2012 and placed the 520,000 cubic yards yd3 of dredged sand as a swash-zone berm nearshore of Perdido Key, FL. Beach quality sands are a valuable resource within the coastal zone in maintaining regional sediment balance. Compared to a typical beach fill or direct beach placement, nearshore berm placement in this case a swash-zone berm has advantages of being less costly with more lenient regulatory restrictions on sediment type and monitoring requirements Hands and Allison 1991 McLellan and Kraus 1991. The Perdido Key berm was designed to be an active berm that would quickly mobilize sediments in the energetic swash zone. The goal was to beneficially use maintenance dredged material to nourish the littoral environment adjacent to Pensacola Pass, and to have an immediate impact on the narrow subaerial beach. This CHETN documents the initial morphological evolution of the Perdido Key swash-zone berm placement based on analysis of beach-nearshore profiles, sediment samples, and nearshore wave data. The eastern portion of Perdido Key, including the present study area, was nourished in 1985 and 1989 Dean et al. 1995. The 1985 beach nourishment was constructed to a berm height of 10.3 ft NAVD88, whereas the 1989 beach nourishment had a constructed berm height of 4.3 ft NAVD88 Dean et al. 1995 Browder and Dean 2000. The 1989 nourishment also included a nearshore berm placed at roughly -22 ft NAVD88 with a crest height of roughly 5.7 ft. The 2012 Perdido Key artificial berm was placed west of Pensacola Pass Figure 1.
- Hydrology, Limnology and Potamology