The Nehalem Watershed (HUC 17100202) covers an area of around 774 square miles in northwest Oregon. The watershed is home to several streams and rivers, including the Nehalem River, which is the largest river in the region. The hydrology of the watershed is characterized by a high amount of rainfall, with an average of 120 inches per year. The specific snowpack in the area is minimal, and the majority of precipitation falls as rain. Surface water in the Nehalem Watershed is of high quality, with low levels of pollutants. However, the area is characterized by a high number of dams and reservoirs, which can impact the natural flow of water and sedimentation processes. Interesting climatic facts and trends include a warming trend in the region, with temperatures increasing by 1.5°C over the past century. This trend is expected to continue, with more extreme weather events and increased precipitation variability.