Impacts of peaking generation on water quality in the tailwater of lake Tex
oma, on the Texas and Oklahoma border, were evaluated during summer stratif
ication in the lake. Sampling was conducted before, during, and after a dai
ly generation cycle with measurements of temperature, dissolved oxygen, iro
n, manganese, and turbidity. Temperatures were near 25 degrees C during gen
eration, fluctuated 3-4 degrees C during nongeneration, and increased in a
downstream direction to near 28 degrees C. Dissolved oxygen concentrations
were between 4 and 6 mg L-1 during generation and increased in a downstream
direction. During nongeneration, concentrations in the upstream region of
the tailwater were near 2 mg L-1 but were between 4 and 10 mg L-1 in the re
st of the study area. Maximum concentrations, 6 to 10 mg L-1, were observed
prior to the hydrograph peak at each station, suggesting leading edge effe
cts of increased flow and aeration as substrate was covered during river st
age increases. Concentrations of metals increased in a downstream direction
coincident with turbidity increases from near 3 to 25 NTUs, suggesting res
uspension and possibly flocculation. Dissimilar patterns were observed for
nongeneration when concentrations decreased in a downstream direction while
turbidity was relatively constant and lower than generation values, sugges
ting settling with decreased flow.