About The Watershed


The Lower Nehalem Watershed:

  • Covers 310 sq miles
  • Is a rain-forest receiving between 100 and 200 inches of rain each year (see annual rainfall on the left).
  • Is managed primarily for timber production.  Fifty two percent of the land is owned by the State of Oregon and managed by the Oregon Department of Forestry.  Private Timber companies own 31.6 percent of the land and the remaining 16.4% is farm land or zoned for urban and rural development.  It includes the Nehalem estuary, and four fifth field watersheds:
    • Cook Creek,
    • North Fork Nehalem,
    • Salmonberry and
    • Mid Nehalem

    • Lower Nehalem Map

    During the last 10 years the Lower Nehalem watershed council and its partners have conducted a series of studies that have produced consideral information on conditions in the Nehalem watershed.  These studies include:

    Collectively these studies have shown that salmon production and survival in the Lower Nehalem is limited by reduced stream complexity, high stream water temperatures, and impedimants to fish passage.


    • Historical stream management pratices included removal of large wood from streams, sometimes to allow floating logs to the mills down stream and sometime in the mistaken beliief that removing large wood would create better conditions for salmon production.  We have learned that large wood is actually an important part of the stream habitat needed for salmon production as it creates a varity of conditions that support both salmon spawning (spawning gravel) and rearing (stream pools).  Habitat surveys and the Nehalem Data Synthesis project have allowed us to identify areas in the watershed that need more large wood. (See Large Wood links at the left)
    • Salmon perfer low water temperatures, Coho salmon which were on the endangered species list duing the late 90's need cold water for spawning in the fall and also cold water during the summer for rearing.  Historical logging and farming pratices removed stream side trees allowing direct sunlight to warm the stream waters.  The stream habitat studies and the Nehalem Data Synthesis project have allowed us to identifiy those areas in the watershed most in need of additional trees to provide needed shade (see Riparian Planting Need at the left).
    • Logging, farming, and rural development have created a extensive network of roads in the Lower Nehelam watershed.  The combination of the road and streams produces produces a large number of road stream crossings.  Most of these road stream crossings involve the use of culverts.  Some of these culverts become barriers to fish passage.  This results steam segments that can not be accessed by migrating salmon and hence a reduction in the area available for spawning and rearing.  Visits to road crossing coho streams resulted in the identification of 22 culverts that appeared to be barrriers to fish passage.  Most had a limited impact on available habitat.  The culverts at Jetty Creek, Roy Creek, and Neahakahnie Creek showed the greatest impact on available salmonid habitat.  The Jetty Creek culvert was replaced by a bride in 2008, and the Neahkahnie and Roy Creek culverts are on track toward replacement.
    • Tide gates are used to keep high tides from flooding farm land around the Nehalem Estuary.   These tide gates can also block access to potential salmon habitat. (see Barriers maps at left)

    These three watershed problems have been the focus of the State and Lower Nehalem Watershed Council efforts, however the studies have also shown the exixtance of other water quality problems in the watershed. 

    • E-coli, mostly produced by farm animals, sometimes reaches high levels in streams and rivers.  This e-coli can be a danger to human health through contact during recreational activities.
    • Low water flows during the summer can contribute to high stream temperatures and smaller areas of water available for Coho salmon rearing.  Summer water flows are reduced as farmers take water from the river for use with their crops and livestock.
    • Excessive stream sediment can burry salmon eggs and reduce salmon productivity.  Unfortunately we do not have standards for sediment, and as a result this problem has recieved less attention than it probably deserves.  Timber owners, however, have been putting addditional rock on their dirt roads to reduce the discharge of fine sediment into streams.

    Parcipitation map