Auke Lake is Auke Lake is a freshwater lake located approximately 12 miles north of downtown Juneau, Alaska (Figure 1).Oriented roughly northwest to south, the watershed encompasses approximately 2,558 acres, with elevations ranging from sea level to just over 2,000 feet. Auke Lake itself covers a surface area of approximately 177 acres and has a maximum depth of 113 feet. The lake surface rises 56 feet above sea level and the forested shoreline consists of a mix of gentle slopes and steep-sided banks.
Development in the immediate vicinity of the lake is limited with this highest density existing at the Southwest corner where the lake meets the University of Alaska Southeast campus. Lake usage increases on weekends in the summer and public boat ramp is located at the southern end of the lake.
Water Quality Summary
Water quality data for Auke Lake and its tributaries is limited. The most extensive data available is water temperature in the lake and some of the tributary streams. Other data include standard water quality parameters such as dissolved oxygen, pH, selected cations (such as iron, magnesium, calcium, etc.), some anions (such as fluorine, chlorine, and sulfate), conductivity, hardness, alkalinity, and nutrients. Less common are data for benzene, toluene, ethylbenzene, and xylene (BTEX), and polycyclic aromatic hydrocarbons (PAH), which had been collected as part of a study to determine the effect of motorized water craft on water quality in Auke Lake (Rice et al., 2008.) Concern about the effect of motorized water craft use on Auke Lake prompted water quality studies to assess PAH concentrations in relation to recreational use of the lake. Studies conducted by NMFS in 1995-2003 showed that increases in PAH concentrations in surface waters coincided with the increase of two-stroke engine water craft on the lake. PAHs were detected in surface waters at a depth of 1 meter, but not at 9 meters (Rice et al., 2008)
Out of a continued concern for water quality in regards to motorized usage, the Juneau Watershed Partnership is conducting a user survey beginning in June 2012 through June 2013. The user survey is conducted on a daily basis and records the number of users, types of usage, and location of primary use. This information is being complemented with targeted water quality sampling. This means that sampling is only being conducted on days when a high number of motorized users are present.