The Truckee River Biomass Monitoring (TRBM) program collected data regarding algal biomass in the lower Truckee River [expressed as plant pigments (chlorophyll a), carbon, nitrogen and phosphorous] that can be used for independent analysis of ecosystem health and nutrient budgets. Furthermore, the biomass sampling program has been implemented in such a manner that the results will be used to validate water quality models and, hence, to make model formulations more scientifically defensible as management tools.