Figure 46. Open-marsh water management plan to eliminate mosquito 

 breeding in depressions (cross-hatched) by building ponds (hatched) 

 and by ditching (Source: Reference 146). 



Band ditch 



To maintain the water table level, weirs can be built across the 

 channel at strategic heights (between mean high water and mean sea level). 

 A variation of this technique is practiced in Louisiana, where weirs (low 

 dams) are used to hold the water level in tributary creeks and ponds to 

 a minimum depth during neap (low-range) tides. The use of weirs provides 

 for ecological management, boat access and incidental benefits of mosquito 

 control . 



The open-marsh approach can be used to rehabilitate thousands 

 of acres of salt-marsh wetlands in many areas of the U.S. that have been 

 seriously degraded by ditching and draining. An appropriate system of 



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