1 Background and Problem 

 Statement 



This report documents a joint case study conducted by the U.S. Army 

 Engineer Research and Development Center (ERDC) Coastal and Hydraulics 

 Laboratory (CHL) and Taylor Engineering, Inc., to assess the functioning of the 

 Diagnostic Modeling System (DMS). In this case study, shoaling patterns at a 

 Federal waterway at East Pass, Florida, provide an evaluation site for trial 

 application of the DMS. The shoaling at the entrance channel at East Pass Inlet 

 serves as the second exercise and evaluation of the DMS concept (for the first 

 application, see Kraus, Mark, and Sarruff (In preparation)). 



Background 



The DMS is being developed under the Coastal Sedimentation and Dredging 

 Program administered by the U.S. Army Corps of Engineers (USACE). The 

 DMS is intended to provide the USACE with a rapid, yet reliable, capability to 

 develop and evaluate navigation channel operations and maintenance (O&M) 

 alternatives based on limited information on the hydrodynamic and sediment- 

 transport conditions at a site. 



The DMS gives a rapid evaluation or diagnosis of a problem shoaling area 

 and provides guidance for deterniining possible solutions. The economic lever 

 underlying the DMS concept is that a low-level analysis, possibly supplemented 

 by a modest numerical modeling effort, can yield substantial cost savings without 

 interrupting ongoing O&M activities and schedule. That is, the DMS is intended 

 to provide feasible alternatives for reducing O&M costs within the dredging 

 cycle of the subject project. The application time and effort in applying the DMS 

 are relative to the maintenance time of the project. 



Taylor Engineering is currently developing the State-mandated inlet manage- 

 ment plan for East Pass in cooperation with the City of Destin, Okaloosa County; 

 the Florida Department of Environmental Protection, Bureau of Beaches and 

 Coastal Systems; and the U.S. Army Engineer District, Mobile. The Mobile 

 District identified a study site in East Pass, Florida, where dredged volume is 

 increasing and navigation is becoming more difficult. This report describes the 

 application of a DMS approach to East Pass. 



This chapter begins by presenting an overview of the DMS methodology and 

 follows with a description of the case study area. This description includes a 

 short history of the area, a discussion of the physical processes, and a listing of 



Chapter 1 Background and Problem Statement 



