Department tracking rainfall and streamflow for 2020 New data from the Department of Water and Environmental Regulation (DWER) has shown a late start to streamflow at many sites following good May rainfall across most of the South West land division. Despite the average to above average rainfall, streamflow was below average for most sites during May and also for the year to date. This follows on from dry conditions experienced across the South West of the state in 2019. Streamflow data for May showed that 58 per cent of sites recorded well below average flow and 21 per cent below average flow, with only the sites at Wilyabrup Brook, Margaret River and Lort River recording average streamflow for May and the year to date. The Denmark River gauging station recorded its first flow at the start of June. This is the first time the site has recorded no streamflow in the first five months of the year since records began.
Sites on the Swan River and Thomson Brook also recorded no streamflow until the start of June, and the Frankland River gauge recorded its lowest reading for January to May since 1975. In total five sites recorded their lowest January to May streamflow totals and only Margaret River, Wilyabrup Brook and Lort River recorded average streamflow for the period.
DWER measurement at Roe Highway on the Helena River.
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The Overflow - Winter 2020
DWER tracks rainfall at 36 sites and streamflow at 19 sites across the South West of the state and the data for May shows average to above average rainfall at 34 of the sites (56 per cent recorded average levels and 39 per cent recorded above average levels). For the year to date (January to May) two thirds of the sites recorded average rainfall with the Kent River and
