The entire watershed area that feeds the Necanicum Estuary covers about 87 square miles of drainage systems including the Necanicum River, the Neawanna creek and the Neacoxie Creek. The approximately 400- acre Necanicum Estuary land is likely one of the most preserved, even though up to 65 or 70 percent has been filled, said Maine, adding the site of the Seaside Convention Center used to be estuary. The Estuary has been classified as a Conservation Estuary by the State Of Oregon because of its lack of maintained jetties or channels and its close proximity to an urban area. This designation ensures that land use planning and management must uphold certain goals and requirements to preserve the natural rescources and benefits while allowing some development. The City Of Seaside's Comprehensive Plan and the Necanicum Estuary Plan promote the protection and restoration of marsh area, riparian vegetation, fish and wildlife habitat and water quality while minimizing the impacts of development.
Many unseen forces influence the way the estuary works and the species that inhabit it.
The Flow of streams and rivers into the estuary and ocean, or the energy of the tide are not sufficient to mix the column of water. Within that large system, there are numerous dynamic processes going on, said Maine. Processes that influence the estuary system begin in the mountains and watersheds which feed the sreams that run into the estuary. Streams which directly feed the estuary are the Neawanna and the Neacoxie. The Neacoxie has large open space marsh areas at the confluence of the Neacoxie and the Neawanna.