Effects of Urbanization on the Truckee River

Urbanization has been shown to be detrimental to the natural environment. The rapid growth of urbanization globally and in the southwest United States particularly, has created the need for studies that quantify the effects of urbanization on water quality and aquatic ecosystems.  The purpose of this study was to quantify the effects of urbanization on the lower Truckee River watershed and to quantify the relation of urbanization, water quality, and aquatic ecosystem condition in the study area. One way to estimate potential toxicity impacts is to deploy passive samplers that accumulate many organic contaminants associated with anthropogenic landscapes. Semipermeable membrane devices (SPMDs) use a lipid to mimic bioaccumulation of hydrophobic organic contaminants (HOCs), including polycyclic aromatic hydrocarbons (PAHs), pesticides, and industrial compounds. We investigated effects of land use and streamflow on the presence of HOCs and potential toxicity in the Truckee River and Lake Tahoe watersheds of Nevada and California.

Objectives

Determine sources and distribution of organic contaminants that are detectable by SPMDs and POCIS (polar organic chemical integrative samplers) along the Truckee River from Farad to Pyramid Lake.  In addition potential toxicity was also measured in streams that are tributary to Lake Tahoe.  These data were used to correlate organic contaminant distribution to urban and natural variables along the river to determine if water quality is affected by urbanization or other factors.

Strategy and Approach

SPMD and POCIS devices were placed in the Truckee River, Steamboat Creek (a major tributary to the Truckee) and the North Truckee Drain (a major agricultural and urban drain). (Figure 1).  The passive samplers were deployed for 1 month at high flow and low flow during a three year period and then removed and analyzed for non polar organic contaminants such as PAH, organochlorines, fuel compounds, and polar organic compounds such as pharmaceuticals. In addition, toxicity tests were also conducted during the first three years of the study. The sites included areas dominated by urban land uses, agricultural land uses, and a reference site. Samplers were also placed upstream and downstream of the treated effluent outfall to determine the integration of all sources, how much mixing occurs, and what is the total contribution of Steamboat Creek to the Truckee River.  Urbanization variables were determined using various methods and correlations were determined using principal component analysis (Rosen and others, 2006; Rowe and others, 2005; Arufe, 2006).  In addition stable isotopes of carbon and nitrogen were used to determine downstream changes in the aquatic food-web (Saito and others, 2007 Saito and others, in press) and a comparison of the isotopic changes and organic contaminants showed further correlation between land use and contaminant distributions.  Further work is needed to quantify the effects of these contaminants on the aquatic ecosystem.  

Figure 1.  Sampling sites at Lake Tahoe and the Truckee River watershed.

Relevance and Benefits

Identifying where surface-water degradation is occurring and the factors related to these changes will help the cities of Reno and Sparks manage existing water-quality issues, plan development of the cities so they will have minimal impact, and maintain the ecology of Steamboat Creek and the Truckee River. It is relevant that the USGS conduct this study because evaluating the water quality of rivers is directly related to the mission and long-term plans of the Environment and Natural Resources goals in the USGS Strategic Plan (USGS, 2000) and issue 2, Human Health, of the Nevada Water Science Center Science Plan. This study also will help the USGS National Water Quality Assessment Program meet its goals of describing trends in the quality of the Nation's water resources and describing factors related to those trends.

Publications

Arufe, J.A., 2006, Urbanization, Water Quality, and Aquatic Ecosystem Condition in the Lower
Truckee River Watershed: University of Nevada, Reno, Master's Thesis, 149 p.

Rosen, M.R., Rowe, T.G., Goodbred, S.L., Shipley, D.O. and Arufe, J.A., 2006, Importance of land use, streamflow, and water quality on toxicity of SPMD extracts deployed in streams from the Lake Tahoe and Truckee River Watersheds, in Hughes, R.M., Wang, L., and Seelbach, P.W., eds.,  Influences of landscapes on stream habitats and biological assemblages: American Fisheries Society, Symposium 48, p. 125-149.

Rowe, T.G., Rosen, M.R., Goodbred, S.L. and Shipley, D.O., 2005, Relation between urbanization and relative toxicity of semipermeable membrane device extracts in the Lake Tahoe Basin and Truckee River watershed, Nevada and California:  Journal of the Nevada Water Resources Association, vol. 2, no. 1, p. 58-89.

Saito, Laurel, Redd, Christa, Chandra, Sudeep, Atwell, Lisa, Fritsen, C.H., and Rosen, M.R., 2007, Quantifying foodweb interactions with simultaneous linear equations--stable isotope models of the Truckee River: Journal of the North American Benthological Society, v. 26, no. 4, p. 641-661

Saito, L., Rosen, M.R., Chandra, S., Atwell, L. Fritsen, C.H., Arufe, J.A. and, Redd, C., in press, Using semi-permeable membrane devices and stable nitrogen isotopes to detect anthropogenic influences on the Truckee River, USA.  Environmental Engineering Science.