Steamboat Creek in western Nevada is the largest contributor of non-point n
utrient pollution to the Truckee River, which connects Lake Tahoe to termin
al Pyramid Lake. Lands adjacent to Steamboat Creek receive, on average, sev
en inches of precipitation annually. Land uses in the Steamboat Creek basin
are agricultural, urban, and undeveloped. Steamboat Creek is a complex sys
tem due to the presence of numerous irrigation diversions and the Steamboat
Springs geothermal area. The Steamboat Creek basin is experiencing urbaniz
ation of agricultural and undeveloped lands. Historic water quality data wa
s analyzed to identify trends associated with different land uses adjacent
to the creek, seasonal flows, and irrigation regimes. Three Lagrangian-styl
e water quality surveys were performed-one each during high flow with irrig
ation, medium flow with irrigation, and low flow with minimal irrigation. E
ach water quality survey occurred during dry conditions and followed dry an
tecedent conditions. Hydrodynamics, nutrient flux, and diel variation of di
ssolved oxygen concentrations associated with periphyton productivity will
be simulated using the Water Quality Analysis Simulation Program Version 5
(WASP5).