4.6.8 Filling 



Landfill is a problem mostly where wetlands or watercourses 

 are involved. Wetlands should not be bulkheaded and filled (see 

 Section 4.3). Natural watercourses should not be blocked by solid fill; 

 appropriate size culverts or bridges should be used (see Section 4.8). 

 General fill should be stabilized as rapidly as possible with vegetation 

 or artificial means (see Section 4.5). 



4.7 ARTIFICIAL WATERWAYS AND WATER BODIES - SUBPROJECT 7 



Canals and ditches of many kinds are cut for various access, drain- 

 age, fill and conveyance purposes. They are dug to drain shorelands for 

 agriculture, and for home building and mosquito control. Canals, ponds 

 and lakes sometimes result from dredging to provide fill for housing, 

 dikes and roadbeds. Other purposes of canals include access for barges 

 and inland navigation, placement of transmission lines, and conveyance of 

 stormwater, power plant cooling water and (to a limited extent) irrigation. 

 Such waterways characteristically disrupt water flow patterns, degrade 

 water quality, and infringe on vital habitats. 



As used here, artificial waterways are those that are cut through the 

 intertidal zone (including wetlands) or the shorelands (channels dredged 

 in Section 4.1). Artificial watercourses are built in conjunction with 

 many of the subprojects examined in this section. 



4.7.1 Summary 



The construction activities discussed here relate mainly to drainage 

 of land, excavation for fill, and dredging for navigation. 



OCS facilities may require artificial waterways, water bodies, 

 or canals for laying overland transmission lines, for navigation, for 

 building dikes around storage tank areas, for miscellaneous site 

 drainage purposes, and perhaps, for graving docks in platform fab- 

 rication yards. Also road and rail links to service bases and repair 

 yards may involve construction of canal just for equipment access. 

 These activities may cause significant adverse effects such as vital 

 habitat alteration, disruption of water flow, water quality degradation, 

 and saltwater intrusion. 



Secondary development induced by OCS activities such as recreation 

 or housing often involves canals, ditches, or artificial lakes. 



4.7.2 Navigation Canals 



There are thousands of miles of navigation canals in the United 

 States that extend inland from the coast. These range in size from large 

 commercial waterways, like the Houston Ship Canal, to homeowner projects 

 aimed at bringing the family boat closer to the backyard. 



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