Water dependant ecological values and non-consumptive social values of rivers and wetlands are maintained through the setting of an Environmental Water Provision (EWP) and an allocation limit that guides licence decisions. EWPs are the water regimes provided as a result of the water allocation decision-making process, which takes into account ecological, social and economic impacts. As part of the EWP process, Ecological Water Requirements (EWRs) need to be determined. An EWR is defined as the water regime required to maintain key ecological values (existing, historical or proposed for restoration) of water dependent ecosystems at a low level of risk. WRM are the leading consultancy in Western Australia for development of environmental flows, and ecologically sustainable yields for river systems. WRM have worked closely with the State Department of Water to develop and apply methods for determination of environmental flows. WRM has skills in ecological values surveys, channel surveys and development of hydraulic models, determination of critical ecology-flow thresholds using River Analysis Package, determination of ecologically sustainable yield (ESY) and proportional abstraction of daily flow (PADFLOW) regimes using RESYM modelling.