Reservoirs are common on medium-sized rivers, and understanding their role in algal production is important. Suspended algal growth typically is limited in rivers because of hydrology and turbidity. Dams are particularly interesting because they increase water residence time and allow algae to be produced. The lower Kalamazoo River has two relatively large impoundments at Morrow Lake and Lake Allegan, which increase the production of algae. There are also a series of smaller impoundments with shorter water residence times between the larger reservoirs, and their influences on algal sources and sinks are less clear. Previous work has found that much of the increase in algal biomass disappears downstream. In the summer of 2008, chlorophyll-a was measured in the water column and on rocks downstream of Morrow Lake. This study found that sestonic chlorophyll decreased downstream of the Morrow Lake and was not related to nutrient concentrations. However, the Kalamazoo River discharge for the year 2008 was higher than 2005, and so the amount of sestonic algae below Morrow Lake was not as high as in previous years and the loss was not as large. Temporal variation in discharge patterns appears to influence algae dynamics.