Monthly time series of simulated de-trended/de-seasonalised biological indicators at 86 bio-monitoring sites in England and Wales based on the modelled response of these indicators to discharge (represented by a standardised streamflow index, SSI) at 76 paired gauging stations. The biological indicators include: (i) Average Score per Taxon (ASPT) (ii) Lotic-invertebrate Index for Flow Evaluation (LIFE) calculated at family-level (LIFE Family) (iii) LIFE calculated at species-level (LIFE Species). The simulation spans the period 1964-2012. Full details about this dataset can be found at https://doi.org/10.5285/2ad542be-e883-4c6e-b198-7d49da62208c