Donnelly River - Scott Road

River condition at the Scott Road site (site code: DR54DONN1, site reference: 6084005) on the Donnelly River catchment has been assessed on several occasions as part of the Healthy Rivers program. The most recent survey was undertaken between 1–2 March 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)

The site was previously assessed during February 2020.

For a subset of the assessments above, water quality loggers were deployed for extended periods (see below). This enabled assessment of water quality responses to changes in climate, streamflow and factors such as the intactness of vegetation within the river corridor. Among other things, this allows detection of sub-optimal water quality conditions which can be missed during the standard 24-hour assessment.

• 2019–2020 (December–April): Healthy Rivers (Department of Water and Environmental Regulation)
• 2022–2023 (December–May): Healthy Rivers (Department of Water and Environmental Regulation)

Other departmental data: The Scott Road site is on the main channel of the Donnelly River. It is located about 15 km downstream of the department's Strickland gauging station (site reference: 608151), which has been in operation since the 1940s. Barlee Brook joins the main channel between the gauging station and Scott Road (about 10 km upstream of the Scott Road site). Flow data is available for several points on Barlee Brook.

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.

Note: gilgies and restricted gilgies were recorded in additional traps placed in a minor tributary running into the sampled reach during the February 2020 sampling (Scott Road Tributary, site ref 6084013). They were not observed at the Scott Road site (DR54DONN1), so their absence from the Scott Road site is not a particular cause for concern.

Only fish and freshwater crustaceans (crayfish and shrimp) that typically inhabit river channels are targeted by the standard SWIRC sampling methods.

Note: collection of fauna from inland aquatic ecosystems across Western Australia requires a license 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 license conditions.