The Obama administration revealed Wednesday an updated five-year plan for restoring the polluted Great Lakes by the year 2020, outlining steps to address toxic pollution, invasive species and farm runoff, as well as restore plant and wildlife habitat.

Since 2009, Congress has appropriated $1.6 billion for the Great Lakes Restoration Initiative, which has helped to rebuild wetlands and protect the eight-state region from invasive species. As of now funding will last through 2015, but the Environmental Protection Agency (EPA), who released the plan, hopes Congress will designate about $300 million a year through 2020.

As the Earth's largest source of fresh surface water, the health of the Great Lakes is of vital importance. The new plan will build on past efforts to clean up polluted sites, deter invasive species like the Asian carp, reduce nutrient runoff from agricultural fields that contribute to harmful algal blooms, and restore habitat to protect native species.

"Supporting sound conservation practices, such as planting cover crops, rotating crops, installing filter strips and restoring wetlands not only helps keep our water clean, it can help create jobs," US Agriculture Secretary Tom Vilsack said in a statement.

The revamped conservation initiative also outlines steps to mitigate climate change, including selecting wetland plants and trees that are more conducive to warmer temperatures and restoring watersheds to prevent erosion and runoff from heavy storms.

In 1987, the United States and Canada identified 47 sites that were designated as "most polluted" areas, and yet just one site had been remedied by 2010. Since then, another highly polluted section has been cleaned up in the last four years, while the plan designates an additional 15 to be restored by 2020.

Algal blooms are to blame, in part, for some of these polluted waters. This past summer, a Lake Erie algal bloom caused elevated toxin levels that ruined water supplies in the Toledo, Ohio area, forcing residents to go without water for two days and resulting in a declared state of emergency.