Wilgarup River - Quintarrup

River condition at the Wilgarup River - Quintarrup site (site code: WR263WILG1, site reference: 6071250) in the Warren River catchment has been assessed on several occasions as part of the Healthy Rivers program. The most recent survey was undertaken between 27–28 February 2023.

Healthy Rivers assessments are conducted using standard methods from the South West Index of River Condition (SWIRC), which incorporates field and desktop data from the site and from the broader catchment. Field data collected include the following indicators, assessed over about a 100 m length of stream:

• Aquatic biota: fish and crayfish community information (abundance of native and exotic species across size classes, general reproductive and physical condition)
• Water quality: dissolved oxygen, temperature, specific conductivity, and pH (logged in-situ over 24 hours), as well as laboratory samples for colour, alkalinity, turbidity and nutrients
• Aquatic habitat: e.g. water depth, substrate type, presence of woody debris and detritus, type and cover of macrophytes and draping vegetation
• Physical form: channel morphology, bank slope and shape, bioconnectivity (barriers to migration of aquatic species), erosion and sedimentation
• Fringing zone: width and length of vegetation cover within the river corridor and lands immediately adjacent, structural intactness of riparian and streamside vegetation
• Hydrology: measures of flow (velocity) at representative locations (compared against data from stream gauging stations within the system)
• Local land use: descriptions of local land use types and activities (compared against land use mapping information for the catchment)

This was the third time the site has been assessed: previous assessments are listed below:

• 2017 (20–21 February): Healthy Rivers - full SWIRC assessment
• 2020 (10–11 February): Healthy Rivers - full SWIRC assessment

Other departmental data: The Quintarrup site is at the Department of Water and Environmental Regulation's (the department) flow gauging station also known as Wilgarup River - Quintarrup (site reference: 607144), which has been in operation since 1961.

Search the site code or site reference in the department’s Water Information Reporting (WIR) system to find data for this site and nearby sampling points (flows, surface water quality, groundwater monitoring, the department's meteorological data). See also the Bureau of Meteorology website for additional meteorological data for the area.

The species expected to occur here are based on species found at the site and elsewhere within the wider subcatchment. As differences in habitat within a reach naturally influence species distributions, and variability in methods between sampling programs can affect the species caught, this list is only indicative.

Please note that since the gauging station is the boundary between two subcatchments (for fish expectation) there are two fish tables. Table one refers to upstream of the gauging station weir and table two refers to downstream of the weir. Future assessments will treat upstream and downstream of the weir as two separate sites.

The expected native fish for this site includes the western mud minnow, which has previously been observed in the subcatchment below the weir. This species is listed as vulnerable under the Biodiversity Conservation Act 2016 (Western Australia) and has recently been listed as endangered on the 2019 IUCN redlist of threatened species. The population is now fragmented, attributed to land degradation (increase in salinisation) and changes in hydrology from abstraction and climate change.

Note: collection of fauna from inland aquatic ecosystems across Western Australia requires a licence from the Department of Primary Industries and Regional Development (DPIRD) and the Department of Biodiversity, Conservation and Attractions (DBCA). All species collected must be reported to these agencies as part of licence conditions.

Only freshwater fish and crayfish that typically inhabit river channels are targeted by the standard SWIRC sampling methods, however other species are sometimes captured or observed.  The following species were detected at the site:

• South-western snake-necked turtles (Chelodina oblonga)were observed in 2017 and 2020.

Macroinvertebrate sampling has not been carried out at this site as part of the SWIRC assessments to date.

For more information on recorded aquatic fauna and other aquatic species, please see the River Science fauna page.