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What is an Estuary?
Map of Oregon estuaries with classificationsAn estuary is defined as a semi-enclosed body of water, connected to the ocean, where salt water is measurably diluted with fresh water from the land. In reality, an estuary - or bay - is a whole lot more. It is a zone of transition between the marine-dominated systems of the ocean and the upland river systems, a zone which yields one of the most biologically productive areas on Earth.
Oregon has 22 major estuaries and many other minor estuaries along its coast. Most of the larger estuaries have been altered through dredging, filling or diking. Many of the smaller ones have escaped the impacts of civilization and remain in a natural state. All are important and are covered by Oregon's estuarine management program.

Who is in Charge of Estuaries in Oregon?
Twenty-two cities, seven counties, and thirteen port districts have planning or management responsibilities for Oregon's major estuaries. Counties, in coordination with cities and port authorities, have the overall responsibility for preparing management plans for their respective estuaries. Administration of those plans is done by the relevant cities and counties as part of their overall comprehensive planning responsibilities. Port districts support development and maintenance of navigation improvements for water-oriented industry and commerce, as well as commercial fishing and recreational boating and fishing. Ports also play a key role in planning and implementing economic development strategies for the areas they serve. Click for a diagram of terms and jurisdictional extents relevant to estuaries.

Estuary Management
Statewide Planning Goal 16, Estuarine Resources (pdf),establishes detailed requirements for the planning and management of Oregon's estuaries. The overall objective is to "recognize and protect the unique environmental, economic and social values of each estuary and associated wetlands and to protect, maintain, and, where appropriate, develop and restore the long-term environmental, economic, and social values, diversity and benefits of Oregon's estuaries." To accomplish this, Goal 16 sets broad requirements for preparation of plans and for review of individual projects. It calls for coordinated action by all local, state and federal agencies that regulate or have an interest in Oregon's estuaries.
Goal 16 provides for management of estuaries in three ways:
  • First, LCDC has established a coast-wide classification system to maintain diversity between and among the state's estuaries.
  • Second, individual estuary plans designate appropriate uses for different management units [see below] within each estuary.
  • Third, local plans must provide for review of estuarine alterations to assure that they are as compatible as possible with the protection of estuarine values.

Management Unit Designation
Plans are prepared for each estuary by the affected cities and counties with input from the public and other interested units of government. Plans divide each estuary into a number of different zones or areas called management units. Goals 16 directs what kinds of areas are to be included in each management unit and what kinds of uses can be allowed in each type of management unit.

Project Review
Estuary plans must also include procedures and standards for review of proposed estuarine developments. Project review requirements are designed to ensure that new uses or alterations are compatible with resources in the area and that harmful effects are minimized. Most project review requirements are applied through review of permits for specific development projects.

Types of Estuaries

LCDC has adopted an estuary classification systemwhich defines the overall level of development permitted in each estuary [see chart below]. This system is designed to preserve diversity among Oregon's estuaries and guide development of estuaries that have been altered and which can support more development.

NaturalSand Lake
Salmon River
Elk River
Sixes River
Pistol River
Sand Lake, an example of a natural estuary
Natural Estuary
Natural estuaries lack maintained jetties or channels, and are usually little developed for residential, commercial or industrial uses. They may have altered shorelines, provided that these altered shorelines are not adjacent to an urban area. Shorelands around natural estuaries are generally used for agriculture, forestry, recreation and other rural uses. Natural estuaries have only natural management units.
ConservationNecanicum River
Netarts Bay
Nestucca River
Siletz Bay
Alsea Bay
Winchuck River
Winchuck River, an example of a conservation estuary
Conservation Estuary
Conservation estuaries lack maintained jetties or channels, but are within or adjacent to urban areas which have altered shorelines adjacent to the estuary. Conservation estuaries have conservation and natural management units.
Shallow Draft DevelopmentNehalem Bay
Tillamook Bay
Depoe Bay
Siuslaw River
Umpqua River
Coquille River
Rogue River
Chetco River
Nehalem Bay, an example of a shallow draft development estuary
Shallow Draft Estuary
Shallow draft development estuaries with maintained jetties and a main channel [not entrance channel] maintained by dredging at 22 feet or less. Shallow draft development estuaries have development, conservation and natural management units.
Deep Draft DevelopmentColumbia River
Yaquina Bay
Coos Bay
Coos Bay, an example of a deep draft development estuary
Deep Draft Estuary
Deep draft development estuaries with maintained jetties and a main channel maintained by dredging to deeper than 22 feet. Deep draft development estuaries have development, conservation and natural management units.

Other Estuary Links
Online Version of DLCD's Estuary Plan Book (this link leads to a different site; use your browser's back button to return to this site).