Figure 27. An improperly designed artificial lake or borrow pit 

 (Source: Adapted from Reference 72). 



Runofi from 

 roads and 

 paved areas 





Growth ot ur^desirable 

 plants, such as hvacinths 



Direct flow of runoff from 



Structures and 

 open areas 



Groundwater threatened 

 ■ bv high transmissibilny of ti'/.V.'^^Vi 

 , aquifer 



TW 



^i= 



Dying plants f«M to bottom 



■--frj-T 



Anaerobic zona 



ulation of ooze 



Maximum depth of light , 

 penetration <s 8 to 1 2 feet 



Bottom buildup of ooze 

 and decaying ptants 



of these wetlands should accordingly be oriented toward light-duty, 

 non-altering uses. If properly controlled, relatively small altera- 

 tions should not have detrimental effects on water systems and estua- 

 rine resources. Nevertheless, any structure should be designed and 

 built to reduce the harmful effects of shading, water flow interrup- 

 tion, and site disruption. 



Solid-fill roads or other structures in wetlands obstruct water 

 flow. Roadways built through wetlands or over wetland swales should 

 be elevated on pilings rather than placed on fills. 



As a rule, discharge or release of pollutants into the wetlands 

 should be prevented. There may, however, be some capacity for the 

 wetlands to absorb certain storm runoff pollutants and thereby to function 

 as a "land treatment" system. Any such pollutants should not exceed the 

 calculated receiving capacity of the system and should not degrade surface 

 water or groundwater below allowable standards. 



120 



