This dataset contains information about submersible absorbance sensor responses to varying suspended sediment concentration, grain size and organic content. Laboratory tests were conducted at the University of Birmingham, UK, during 2023 as part of a wider study developing methods for urban storm flow characterization. Two sediment types were assessed along with three size fractions across concentration ranges from 0 mg/L to 5000 mg/L. Absorbance was recorded at key wavelengths between 190 – 360 nm and particle size distribution and organic content (loss on ignition) measured for each sediment type and size fraction. The work was supported by the Natural Environment Research Council (Grant NE/X011178/1). Full details about this dataset can be found at https://doi.org/10.5285/ee577b07-1a2c-4541-bf30-e2ea048e15e1