This project was designed to explore the role played by carbon and its subsequent use by bacteria on various chemical and biological parameters in Dworshak reservoir. Carbon contribution to the reservoir is primarily from the existing organic materials present on the preimpoundment floor. This study defines methodology enabling prediction of the levels of carbon in a reservoir prior to impoundment and explores some of the effects of that carbon. In addition, these methods can be used to determine the amount of leached carbon, readily useable, by heterotrophic bacteria. The effect of carbon utilization by bacteria on algal growth is also explored. In the laboratory this symbiotic effect leads to significant increases in algal biomass even at carbon levels as low as 1.3 ppm. The implication of this observation is that carbon can greatly stimulate algal growth rates and consequently algal blooms if made available by bacterial respiration. (Modified author abstract)