Dataset: MER Hydrology Condition Assessment - Unmodelled Catchment - Derived Dataset


To generate a Hydrologic Condition as part of the State of the Catchment reporting for the whole of NSW an alternative to the Sustainable River Audit (SRA) approach, used for river systems with IQQM models, was required for river systems that had not been modelled. This dataset is the result. The alternative index selected was the ratio of annual licensed entitlement to estimated low flow annual volume (90th percentile exceedance annual flow), which is similar to the modelled low flow year distributed layer developed by Janet Stein. The differences being; catchment polygons were used instead of a stream network to allow corrected entitlements total to be used, (Note the entitlement layer used by Stien didn't include large Major Water Utility licences and TWS licences. Also note the conditions rating was rolled up to basin level, hence distributed condition ratings were not required.), total entitlements in catchments used instead of the limited point licence layer, and end of catchment annual 90th percentile flows were estimates from regionalised relationships with measured flows (Note the Stien modelled flow while indicative of the Coastal River flows didn't reflect measured flows all the way along the coastal catchments).

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