In the UK, there are competing demands for both surface and groundwater resources. Sustained or repeated periods of low flows and/or slow flows are expected to impact on the plant and animal communities within rivers. To assess the potential impact of flow-related stresses on lotic macroinvertebrate communities, the Environment agency developed the Lotic-invertebrate Index for Flow Evaluation (LIFE). Extence et al. (1999) showed that for several individual sites, temporal
variation in LIFE could be correlated with recent and preceding flow conditions.
RIVPACS (River InVertebrate Prediction And Classification System) is the principal methodology currently used by the UK government environment agencies to assess the biological condition of UK rivers. RIVPACS assesses biological condition at a site by comparing the observed macroinvertebrate fauna with the fauna expected at the site if it is unstressed and unpolluted, as predicted from its environmental characteristics.