navigation to support the booming oil 

 industry. Levee and channel exten- 

 sions are planned to alleviate these 

 problems, but negative impacts as- 

 sociated with salinity intrusion and 

 marsh deterioration are feared if the 

 projects are built. 



Other alternatives under con- 

 sideration to aid these interests 

 involve changes in distribution of 

 flow between Wax Lake Outlet and the 

 lower Atchafalaya River. Wax Lake 

 Outlet is experiencing rapidly in- 

 creasing flows at the expense of the 

 lower Atchafalaya River because of 

 its shorter route to the gulf. This 

 is causing increased shoaling near 

 Morgan City and loss of channel 

 cross-sectional area for flood con- 

 veyance past Morgan City. 



Among the proposals under con- 

 sideration by the Corps of Engineers 

 to alleviate this problem is a plan 

 to construct a weir or overbank struc- 

 ture above Wax Lake Outlet. This 

 structure would restrict the passage 

 of normal flows while allowing high 

 flows over the weir during flood 

 events. The project would increase 

 normal flows past Morgan City, en- 

 couraging natural channel scour, and 

 hopefully result in an improved flood 

 conveyance and improved navigation. 



A citizens group from Morgan 

 City has proposed a complete closure 

 of the Lower Atchafalaya River above 

 Morgan City, with 100 percent of the 

 flow exiting at Wax Lake Outlet. 

 While this plan would afford flood 

 protection, the cost, coupled with 

 negative environmental impacts, makes 

 it infeasible. 



None of these proposals will 

 substantially alter long-term delta- 

 building processes in the region; 

 they will merely change the focal 

 point of the impact. Regardless of 



the approach, there are urgent overall 

 needs for Louisiana to capitalize on 

 these deltaic processes. 



Numerous studies have shown that 

 a renewed cycle of delta growth is 

 essential for the replacement of lost 

 land and the maintenance of environ- 

 mental productivity in the coastal 

 zone as a whole. The regenerative 

 effects of deltaic sedimentation are 

 particularly necessary for the long- 

 term health of Louisiana's seafood 

 industry. The economic hardships for 

 fishing and navigation interests in 

 the Atchafalaya-Vermilion area can 

 be eased, but not prevented. Perhaps 

 the addition of new land will stim- 

 ulate economic alternatives for this 

 region, similar to the development 

 between New Orleans and Venice, 

 Louisiana . 



Habitats and fishing grounds can 

 shift in location and character in 

 response to these deltaic processes. 

 Unfortunately, people cannot. Econo- 

 mics dictate the maintenance of the 

 status quo in a highly dynamic geo- 

 logic situation. The greater the 

 superimposition of people and their 

 settlements in a rapidly changing 

 area like the Atchafalaya-Vermilion 

 region, the more complex the prob- 

 lems, and the more difficult the 

 solutions . 



SUMMARY AND CONCLUSIONS 



The study of the subaerial 

 growth and regional impacts of the 

 Atchafalaya Delta have led to the 

 following conclusions: 



1. The subaerial phase of delta 

 development started significantly 

 after the flood of 1973, with abrupt 

 increases in growth occurring follow- 

 ing major flood events. 



363 



