Changes in the physical template of urban streams can occur rapidly due to flashy high flow events.  We investigated three reaches along an urban stream before and after a flash flood event to compare changes in physical stream characteristics due to sudden high flows and to examine how the physical changes may be related to differences in nitrate uptake within each reach.  Our physical characterization of each reach included width variability, longitudinal thalweg, and cross-section surveys.  We also measured bed substrate size, overall bed topography, and benthic organic matter (fine and coarse).  Additionally, we performed nutrient injections to estimate the amount of nitrate uptake occurring over each reach.  Comprehensive data sets were collected along each of the three reaches pre- and post- flood.  Post flood surveys indicated an increase in substrate size and a decrease in benthic organic matter compared to pre-flood conditions.  By estimating the amount of nitrate uptake occurring along each reach before and after flash flood conditions, we explored how sudden changes in physical attributes of the stream may influence the uptake of nitrate.