Forested watersheds across the Northeast and Midwest provide water for more than 76 million people (see pie chart). The health of a forest has a direct impact on the quality of ground and surface waters that arise from it. In general, watersheds with abundant forest have better water quality than those without. Forests help retain runoff, filtering pollutants and sediment from water flowing into streams and lakes. They help keep surface water cool and provide woody debris, sustaining fish and aquatic insects.
Forests also affect the movement of water. When rain falls on non-porous pavement, it flows rapidly into nearby water bodies, carrying pollutants and contributing to flooding. Forested areas gather water in rich, spongy soils and surface depressions, allowing it to filter slowly into ground water and surrounding streams, rivers, lakes, and wetlands.
State and private landowners play a key role in protecting water quality: Nearly 90 percent of the people who use water from forested watersheds in the Northeast and Midwest are served by watersheds on state and private land. Public agencies educate and encourage landowners to manage their land in a way that protects the integrity of the waterways while providing timber production, recreation, and other forest benefits.
Historic forest land clearing degraded lakes and streams through erosion and sedimentation. Many waterways that were used to carry logs a century ago are still recovering.
Forest harvesting practices today are designed to minimize soil erosion and sedimentation. In fact, forest management has less impact on water quality than do agriculture and urban development.
Northeastern and Midwestern forests help protect surface water used by more than 76 million people. State and private forests provide 68.7 million people with water from 512 watersheds and federal forests provide 7.8 million people with water from 86 watersheds.