Reid, N. 2005. Biogeochemical impacts of major reservoirs on the Kalamazoo River. MS. Thesis, Michigan State University, East Lansing, Michigan, USA.
The Kalamazoo River (Michigan, USA) has six run-of-the-river dams. The two hydropower reservoirs’ residence times vary from 2 up to 11 days during the year. The four decommissioned impoundments residence times vary from a quarter of day to 1.5 days during the year. Inflows and outflows for the two hydropower reservoirs were sampled weekly in order to quantify the roles of reservoirs as sinks or transformers for nutrients. Three longitudinal river surveys from Morrow Lake inflow to Lake Allegan outflow were conducted at varying discharges. Special emphasis was placed on above and below Plainwell, Otsego, Allegan City and Trowbridge decommissioned impoundments. Despite their spatial proximity, a Total Maximum Daily Load for phosphorus (P) was deemed necessary for Lake Allegan to control summer algal blooms, whereas Morrow Lake lacks nuisance summer algal blooms. Lake Allegan outflow waters exhibited potential silica and nitrogen limitation in the late summer while Morrow Lake did not, which may explain the undesirable algal blooms in Lake Allegan. The longer residence time allows phytoplankton to build up to undesirable levels within Lake Allegan, but not in Morrow Lake. High algal abundance was observed in the Lake Allegan inflow, which may have resulted from Morrow Lake’s algae transported downstream, or new algal biomass build-up as the river passed through semi-impounded reaches; the results reported here support the latter hypothesis.Sign in to download PDF back to index