own expense. As far as New Orleans goes, if people want to remain in New Orleans, 

 they had better find a new water supply because the Mississippi will eventually 

 abandon its course past the city, maybe in the lifetime of many in the audience. 



The sediment which I indicated is no longer coming down the river is stored in 

 reservoirs in the Arkansas, Missouri, and Ohio rivers and their tributaries. If these 

 reservoirs are reasonably full at the beginning of a flood season, the entire flow of 

 the river will be speeded up. Where formerly the peak in flood stage would slowly 

 rise and persist, now the peak will rise dramatically and to higher levels. The land 

 accretion and erosion in the delta is just the tail end of a tremendous process in the 

 whole river basin which is going on now, and we do not know what the outcome will 

 be. 



Unidentified speaker: If there is a shortage of sediments coming into marshes to offset 

 subsidence, has the nutrient supply also been reduced? Will freshwater diversion 

 increase the needed nutrient supply to allow the marshes to grow? 



Richard Hatton: Many nutrients are associated with particulate sediments, but I feel 

 freshwater inputs would decrease saltwater intrusion which causes marsh 

 destruction. 



Clarice Lozes: Some freshwater diversions could also serve as flood control structures to 

 relieve flood pressure from New Orleans by shortening the flow of river water into 

 Lake Pontchartrain and the Barataria Basin. 



Unidentified speaker: Will these freshwater diversions carry water only during high 

 water periods or year-round? 



Raf)hael Kazmann: High water stages carry more sediment for wetlands accretion. Also, 

 diversions during low stages can worsen saltwater intrusion up the river and affect 

 drinking water supplies. Therefore, substantial freshwater diversion must be 

 confined to relatively high flow periods. 



Unidentified speaker: Wouldn't that present a problem in preventing saltwater intrusion 

 during late summer and early fall when the salinity encroachment tends to be 

 greatest? 



Johannes van Beek: Low flow periods pose a major problem. Also salts may accumulate 

 in soils during episodes of high salinity flooding behind levees. Release of fresh 

 water, when it is available, will help leach the salts from the soils. 



Walter Sikora: Long-term records in Lake Ponchartrain show highest salinity in the fall, 

 but do not show any long-term increase in the western lake. How then could 

 deterioration of freshwater swamps be attributable to saltwater intrusion? 



Johannes van Beek: The break up of cypress swamps seems to be due primarily to 

 increased inundation rather than to increased salinity, but there may be some 

 critical low salinity which affects tolerance to inundation. Therefore, freshwater 

 diversion could increase tolerance to inundation. Also, introduction of more 

 sediments is required to offset the effects of subsidence on increased inundation. 



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