Buffer Zones Preserve Washington's Cool, Clean Water

Trees and vegetation along streams provide critical shade and habitat for Washington's fish and wildlife.

During timber harvesting on private forestland, buffers of trees and vegetation next to streams are protected as they play a critical role in the lives of Washington's wildlife and native fish, especially salmon and trout. The plant communities that form the transition between land and water comprise a riparian zone Protection for these streamside areas were a part of the guidelines set forth by the Forests and Fish Law. As a result of this landmark legislation, buffers are being widened, improved and maintained on more than 60,000 miles of streams on 9.3 million acres of Washington's state and private forestland.

Fish, especially salmon, require cool, clean water. To reach a high quality of water for our fish habitat streams, buffers provide three important functions. The first is to provide shade to keep water temperatures cool, a necessity for spawning salmon. The second is to act as a filter for clean water. Vegetation along stream banks stabilize soils and filters rain and snow runoff--keeping sediment out of the water. The third function of buffers comes from mature trees that fall into streams, due to natural causes. These fallen trees and branches, called large woody debris, block and slow flowing water to create pools. These pools are essential resting and feeding sites for juvenile salmon.

Private Foresters Follow the Forests & Fish Law

As with other aspects of modern day forestry, WFPA's members have a sophisticated understanding of how to manage for maintaining buffer zones during and after the timber harvest. By following the Forests & Fish Law, foresters know, for instance, that timber harvesting is more restricted and prohibited as one moves closer toward the stream. They know that the total width of the buffer is based on tree height and stream size. They know that buffer requirements are quite different in Western Washington than in Eastern Washington. Trained experts practicing responsible forest management, work within a system of requirements provided by the Department of Natural Resources to protect the natural environment and the species living within it.

Different Types of Buffer Zones

When forest landowners negotiated Forests & Fish, they knew it would mean leaving more trees near the stream to provide protection for fish, water, amphibians, and other wildlife species; and they wanted to provide that protection. Negotiations resulted in larger buffers and emergency rules went into effect in 1999.

There are three buffer zones. The Core Zone is a no-touch buffer that extends outward from the stream for a set distance depending on stream size. The Inner Zone (beginning at the edge of the Core Zone) can be managed to allow sufficient growth for healthy riparian areas. Management activities in the Outer Zone are dependent on many complex factors and are dependent on what management occurred in the inner zone.

The buffers are designed to work together to provide protection for aquatic resources and be as economical as possible for forest landowners.

Managing the Health of a Working Forest for Five Decades