[Duck Butter]

Originally Posted by mr crab

its from 1997, but still very comprehensive. I found a lot of answers to questions asked here within this report. It certainly explains the differences between B.L. and Sabine....truly apples and oranges hydrlogicaly spreaking.

good read, the 3rd paragraph really tells the story of why weirs are needed:

Finally, in 1968 the ship channel was substantially widened again to
400 ft and dredged to its current depth of 40 ft (Figure 27; Waldon 1996). Prior to the initial dredging of the CSC, there was a 3.5-ft-deep shoal at the mouth of the Calcasieu River (War Department 1897). This natural bar acted as a constriction, minimizing saltwater and tidal
inflow into the basin. Removal of the channel mouth bar, coupled with subsequent widening and deepening of the CSC, allowed increased saltwater and tidal intrusion into the estuary, resulting in catastrophic marsh loss, tidal export of vast quantities of organic marsh substrate,
and an overall shift to more saline habitats in the region (USDA 1994). In addition, the CSC permits the upriver flow of denser, more saline water as a saltwater wedge. In 1968, the USACE completed construction of the Calcasieu River Saltwater Barrier on the Calcasieu River north of the city of Lake Charles. This barrier minimized the flow of the saltwater
wedge into the upper reaches of the Calcasieu River to protect agricultural water supplies.