Warren River - Barker Rd

River condition at the Barker Road site (site code: WR68WARR1, site reference: 6071251) on the Warren River has been assessed on several occasions as part of the Healthy Rivers program.  The most recent survey was undertaken between 23–24 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 is the third time the site has been assessed; previous assessments are listed below:

• 2017 (22–23 February): Healthy Rivers
• 2020 (10–11 February): Healthy Rivers

Other departmental data: The Barker Road site is located about 2 km downstream of the Department of Water and Environmental Regulation’s (the department) flow gauging station known as Barker Road Crossing (site reference: 607220), which has been in operation since 1966.

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.

The expected native fish for this site include the pouched lamprey, which is a priority 3 species (poorly known) under the Biodiversity Conservation Act 2016 (Western Australia). Priority 3 refers to a species where there is insufficient data to make an assessment and known threatening processes exist that could affect them; however, is not expected to be under imminent threat based on data that are available.  In the early stage of their life cycle, juvenile lamprey (ammocetes) burrow in sand in upper reaches of river systems.  They migrate to the ocean where they may remain and feed for about two years. Eventually lamprey will migrate back to river systems to spawn and die. The absence of lamprey from most SWIRC assessments is not a significant concern as this species typically migrates in a brief period around peak winter flow (which is largely outside of the usual assessment periods) and only in high flow years. Outside of the short migration periods lamprey are unlikely to enter traps.

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:

• Carter’s freshwater mussels (Westralunio carteri) were observed at the site during the February 2022 assessment (and previously in 2020). This species is the sole endemic freshwater mussel species in Western Australia and currently listed as vulnerable on the International Union for Conservation of Nature’s (IUCN) red list of threatened species (because of declining range, which is largely attributed to the effects of salinity).

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

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