
Collie River - Coolangatta Gauging Station Downstream
Basin : Collie River
Catchment : Collie River
River condition at the Coolangatta Gauging Station Downstream site on the Collie River East Branch (site code: CR412COLL2, site reference: 6124034) has been assessed on several occasions as part of the Healthy Rivers program. The most recent survey was undertaken in March 2022.
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 included 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)
All the Healthy Rivers assessments are listed below:
- 2022 summer (February 28–March 1): Healthy Rivers
- 2018 summer (February 19–20): Healthy Rivers
Other departmental data: The Coolangatta Gauging Station Downstream Site is 130 m downstream of the Department of Water and Environmental Regulation’s (the department) flow gauging station known as Coolangatta Farm Gauging Station (site reference: 612001). The gauging station has been in operation since 1968.
Search on 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, department’s meteorological data). See also the Bureau of Meteorology website for additional meteorological data for the area.
Condition summary
A summary of aquatic biota detected over the different sampling events is provided in the section below. For other site data, please contact the department’s River Science team (please reference the site code and sampling dates).
The image below indicates conditions at the time of sampling in March 2022, towards the end of the dry season. March is within the Noongar season of Bunuru, which is the driest and hottest part of the year. Further images are provided in the gallery at the bottom of the page to show general site conditions.

Coolangatta Gauging station Downstream site condition, March 2022.
Species found in subcatchment
Native Species
- Blue-spot gobyPseudogobius olorum
- Freshwater cobblerTandanus bostocki
- GilgieCherax quinquecarinatus
- NightfishBostockia porosa
- Rakali - water ratHydromys chrysogaster
- Smooth marronCherax cainii
- South-west glass shrimpPalaemon australis
- South-western snake-necked turtleChelodina oblonga
- Western minnowGalaxias occidentalis
- Western pygmy perchNannoperca vittata
Species found at the site
Fish and crayfish
The species captured during each of the sampling events are provided in Table 1. The table includes a list of all species previously reported in the sub catchment, which provides an indication of species that may occur at the assessment site. This list is only indicative as differences in habitat within a subcatchment naturally influence species distributions, and variability in methods between sampling programs can affect the species caught.
Eight species of fish and crayfish were captured in the March 2022 sampling. This includes three endemic freshwater fish (nightfish, western pygmy perch and freshwater cobbler), two non-native freshwater fish (eastern gambusia and redfin perch) and three endemic freshwater crustaceans (smooth marron, gilgie and south-west glass shrimp).
Blue-spot goby and western minnow were absent from the March 2022 sampling. The absence of these species during the low-flow period in March 2022 is not considered to be of immediate concern as healthy populations of other endemic freshwater species were present (i.e. the site retains good water and habitat quality). Blue-spot goby were recorded in the February 2018 sampling but in low abundance, and western minnow have not been recorded at this site but have been recorded in subcatchments upstream and downstream of this site and are expected to move through this subcatchment. The lack of detection is expected to be related to low sampling effort (i.e. species are present but were not detected, or species had migrated away from the site temporarily).
The photos of fauna provided are linked to more information about the species, including maps of where each species is expected across the South West.
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.
Other aquatic fauna
Only fish and freshwater crustaceans (crayfish and shrimp) that typically inhabit river channels are targeted by the standards SWIRC sampling methods; however, other species are periodically captured in traps and/or observed (e.g. turtles, rakali native water rats, tadpoles). The following non-target species were identified at this site in March 2022:
- native rakali water rat (Hydromys chrysogaster) – listed as Priority 4 under the 2016 Biodiversity Conservation Act, meaning it is a rare or near-threatened species in need of monitoring
- south-western snake-necked turtle (Chelodina oblonga)
- native bush rat (Rattus fuscipes)
- water birds including Australasian swamphen (Porphyrio melanotus), Pacific black duck (Anas superciliosa) and night heron (Nycticorax caledonicus)

Rakali at the Coolangatta Gauging station Downstream site, March 2022.
For more information on other aquatic species please see the River Science fauna page.
Explore other sites in the catchment
- Brunswick pools
- Brunswick River - Beela Road
- Brunswick River - Big Tree Road Bridge
- Brunswick River - Riverbank Walk
- Brunswick River - Upstream Mornington Road Bridge
- Brunswick River - Upstream of Augustus River
- Chicken Creek
- Collie River - Booth Street
- Collie River - Collie River Road
- Collie River - Collie-Preston Road
- Collie River - Coolangatta Farm Gauging Station
- Collie River - Coolangatta Gauging Station Upstream
- Collie River - Downstream Mungalup Tower
- Collie River - Downstream Rose Road Gauging Station
- Collie River - Hetherington Road
- Collie River - Lennard Track
- Collie River - Minninup Pool
- Collie River - River Road Bridge
- Collie River - Rose Road
- Collie River - Shentons Elbow 2
- Collie River - Treendale Road
- Collie River - Upstream Collie-Williams Road
- Collie River - Upstream Minninup Pool
- Collie River - Upstream South Branch
- Collie River - Wellington Dam Wall
- Collie River East Branch - Duderling Pool
- Collie River East Branch - Quinns Road 1
- Collie River East Branch - Quinns Road 2
- Collie River East Branch - US Diversion Site
- Collie River South Branch - Cardiff Town Pool
- Collie River South Branch - Kepwari outlet
- Collie River South Branch - Long Pool
- Collie River South Branch - McAlinden Road
- Harris River - Downstream Harris Dam 1
- Harris River - Downstream Harris Dam 2
- Harris River - Downstream Tallanalla Gauging Station
- Lake Kepwari - Diversion Inlet
- Lake Kepwari - Diversion Outflow
- Lake Kepwari - River Channel
- Wellesley River - Devlin Road