Fly Brook

River condition at the Fly Brook site (site code: DR12FLYB1, site reference: 6084010) on the Donnelly River has been assessed between 1–2 March 2023 as part of the Healthy Rivers program. The site was previously assessed between 17–18 August 2020.

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). Macroinvertebrate community information is included in some cases, and any other aquatic species caught or observed (e.g., tadpoles, turtles, rakali, mussels) are noted
• 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)

Other departmental data: This site is at Department of Water and Environmental Regulation's (the department) Fly Brook - Boat Landing Rd gauging station (site reference: 608171), which has been in operation since the 1960s (with some gaps in the data).

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.

As this was the first time this site had been sampled, the species expected to occur here are based on species found elsewhere in the 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.

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:

• Bush Rat (Rattus fuscipes) was recorded on motion sensor camera facing an undercut section of bank that looked like a little burrow, with runs up to the top of the bank and under logs.
• Pouched lamprey (Geotria australis) have previously been observed trying to migrate upstream at the weir.

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