Water-Quality, Biological, and Physical-Habitat Conditions at Fixed Sites in the Cook Inlet Basin, Alaska, National Water-Quality Assessment Study Unit, October 1998-September 2001 - Usgs Scientific Investigations Report 2004-5021 (Paperback)

The Cook Inlet Basin study unit of the U.S. Geological Survey National Water-Quality Assessment Program comprises 39,325 square miles in south-central Alaska. Data were collected at eight fixed sites to provide baseline information in areas where no development has taken place, urbanization or logging have occurred, or the effects of recreation are increasing. Collection of water-quality, biology, and physical-habitat data began in October 1998 and ended in September 2001 (water years 1999-2001). The climate for the water years in the study may be categorized as slightly cool-wet (1999), slightly warm-wet (2000), and significantly warm-dry (2001). Total precipitation was near normal during the study period, and air temperatures ranged from modestly cool in water year 1999 to near normal in 2000, and to notably warm in 2001. Snowmelt runoff dominates the hydrology of streams in the Cook Inlet Basin. Average annual flows at the fixed sites were approximately the same as the long-term average annual flows, with the exception of those in glacier-fed basins, which had above-average flow in water year 2001. Water temperature of all streams studied in the Cook Inlet Basin remained at 0 oC for about 6 months per year, and average annual water temperatures ranged from 3.3 to 6.2 degrees Celsius. Of the water-quality constituents sampled, all concentrations were less than drinking-water standards and only one constituent, the pesticide carbaryl, exceeded aquatic-life standards.