Water quality in the great lakes and connecting waterways is impacted by erosion and sewage overflows.Great Lakes advocates are up in arms this week over President George W. Bush's 2009 spending plan, which slashes funding for water quality programs by 16 percent.

According to the Associated Press, environmental groups fear that lower funding will negatively impact efforts to curb invasive species and sewage contamination. Additionally, the president has recommended no spending on erosion control. He has, however, proposed an increase -- though minimal -- in spending on cleaning up toxic sediments in the region's most heavily polluted waterways.

Green groups are now calling on Congress, as well as the presidential candidates, to devote more money to the nation's fresh water supply.