The Peel-Harvey Estuarine System (Nyungar : Djilba) [1] is a natural estuarine system that lies roughly parallel to the coast of Western Australia and south of the town of Mandurah.
The strip of land between the Indian Ocean and the estuarine system carries the Old Coast Road and to the east is the Forrest Highway which is the main thoroughfare between Perth and the coastal towns of the south west corner of the state including Bunbury and Busselton.
The estuarine system, which the Bindjareb Noongar people call Djilba, [1] covers an area of approximately 131 to 136 km2 (51 to 53 sq mi) in total, with an average water depth of about 1 to 2 m (3 ft 3 in to 6 ft 7 in). [2] [3] [4]
The Harvey River discharges into the extreme southern end of the elongated Harvey Estuary, which has an area of about 56 to 61 km2 (22 to 24 sq mi). [2] [3] This in turn feeds into the south-western corner of the more northerly Peel Inlet which is roughly circular and occupies an area of about 75 km2 (29 sq mi). [2] [3] The Serpentine River and Murray Rivers discharge into the eastern edges of Peel Inlet.
A 5 km (3.1 mi) long channel, the Mandurah Estuary (also called Mandurah Entrance Channel or just Mandurah Channel) which passes through the town of Mandurah, then runs into the ocean. [5]
After several decades of severe algal blooms in the estuaries caused by discharge of nutrients from agricultural land and piggeries along the rivers, an artificial channel was constructed and opened in 1994 as the Dawesville Channel. [2] [6] The channel had the effect of allowing saline sea-water to regularly flush the estuary using tidal flows. Whilst the ecology of the estuary has changed markedly due to the flushing process, water quality generally has improved. [7] [6]
The catchment area to the east is largely flat coastal plain with about 75% cleared of native vegetation and used for dryland, dairy and beef grazing. Clearing was done in the early days of settlement to allow agricultural expansion. Drainage systems into the three main rivers have been constructed in much of the catchment to remove excess water quickly.
Lake Preston, Lake Clifton and the Leschenault Estuary are farther south.
The estuary is home to abundant marine wildlife including crustaceans such as the blue swimmer crab (Portunus pelagicus) and the western king prawn (Melicertus latisulcatus) and fish species such as black bream, mulloway, tailor and cobbler. It is regularly visited by dolphins.
The estuary has been identified by BirdLife International as an Important Bird Area because it supports a significant population of fairy terns, is a drought refuge for blue-billed ducks, and sometimes holds over 1% of the world populations of red-necked stints, sharp-tailed sandpipers, banded stilts, red-necked avocets and red-capped plovers. [8]
The estuary is used heavily for recreational boating and fishing with numerous boat ramps and picnic spots along the extensive foreshore with shaded sandy beaches. [5] Houseboats can be hired at Mandurah to explore the estuary and the Murray River.
Urban developments along the shores as well as canal developments in Mandurah and at North and South Yunderup pose significant challenges[ citation needed ] for its successful future management.
Mandurah is a coastal city in the Australian state of Western Australia, situated approximately 72 kilometres (45 mi) south of the state capital, Perth. It is the state's second most populous city, with a population of 90,306.
The Peel region is one of the nine regions of Western Australia. It is located on the west coast of Western Australia, about 75 km (47 mi) south of the state capital, Perth. It consists of the City of Mandurah, and the Shires of Boddington, Murray, Serpentine-Jarrahdale and Waroona.
Bouvard is the second southernmost suburb of Mandurah, Western Australia, and is 97 kilometres (60 mi) south of the state capital, Perth. Its local government area is the City of Mandurah.
Dawesville is a suburb of Mandurah, located adjacent to the Peel-Harvey Estuarine System south of Perth in Western Australia. The Dawesville Cut, a man-made canal built in 1994, is to the north of the suburb.
Falcon is a southern suburb of Mandurah, located southwest of Mandurah's central area and with frontage to the Indian Ocean. The suburb was named after Falcon Bay. Falcon was approved as a suburb name on 13 November 1967 and gazetted on 8 March 1968. Many of the streets in the adjoining estate were named after yachts; "Falcon" itself was the name of a yacht, the crew of which won a silver medal in the 12m² Sharpie yacht races at the 1956 Melbourne Olympics.
Halls Head is a coastal suburb (locality) of Mandurah, immediately west of Mandurah's central area. It is largely residential and contains several canal estates developed since the 1980s.
Wannanup is a residential suburb in Western Australia, located 12 kilometres (7 mi) southwest of Mandurah and 87 kilometres (54 mi) south-southwest of the state capital, Perth. It is surrounded on three sides by water – the Indian Ocean to the west, the Harvey Estuary to the east and the Dawesville Channel to the south – and is home to the Port Bouvard development. It is one of four suburbs which lie on an island created by the building of the Dawesville Channel.
The Serpentine River is a river in the South West region of Western Australia. It is known as Waangaamaap Bilya to the Indigenous Bindjareb people, who met, lived and fished there before British settlement.
The City of Mandurah is a local government area of Western Australia, covering both Mandurah proper and an additional area reaching down as far south as Lake Clifton. The city has a total area of approximately 174 square kilometres (67 sq mi).
Herron is a small suburb located in the Peel region of Western Australia just off the Old Coast Road, between Mandurah and Bunbury just beyond Mandurah's urban area. It is on a narrow strip between Lake Clifton and Yalgorup National Park to the west, and Harvey Estuary to the east.
The Murray River is a river in the southwest of Western Australia. It played a significant part in the expansion of settlement in the area south of Perth after the arrival of British settlers at the Swan River Colony in 1829.
Nornalup Inlet is an estuarine body of water on the south coast of the South West of Australia, approximately 450 km (280 mi) from Perth.
Leschenault Estuary is an estuarine lagoon that lies to the north of Bunbury, Western Australia. It had in the past met the Indian Ocean at the Leschenault Inlet, but that has been altered by harbour works for Bunbury, and the creation of The Cut north of the historical inlet location.
Dawesville Channel is an artificial channel between the Peel-Harvey Estuary and the Indian Ocean at Dawesville, about 80 km (50 mi) south of Perth in Western Australia. It is south of the regional city of Mandurah and north of Yalgorup National Park.
Forrest Highway is a 95-kilometre-long (59 mi) highway in Western Australia's Peel and South West regions, extending Perth's Kwinana Freeway from east of Mandurah down to Bunbury. Old Coast Road was the original Mandurah–Bunbury route, dating back to the 1840s. Part of that road, and the Australind Bypass around Australind and Eaton, were subsumed by Forrest Highway. The highway begins at Kwinana Freeway's southern terminus in Ravenswood, continues around the Peel Inlet to Lake Clifton, and heads south to finish at Bunbury's Eelup Roundabout. There are a number of at-grade intersections with minor roads in the shires of Murray, Waroona, and Harvey including Greenlands Road and Old Bunbury Road, both of which connect to South Western Highway near Pinjarra.
Wilson Inlet is a shallow, seasonally open estuary located on the coast of the Great Southern region of Western Australia.
Broke Inlet, originally named Broke's Inlet, is an inlet in the South West region of Western Australia located 19 kilometres (12 mi) west of Walpole.
The Fortescue River is an ephemeral river in the Pilbara region of Western Australia. It is the third longest river in the state.
Boundary Island is located in the Peel Inlet section of the Peel-Harvey Estuarine System, just south of Mandurah, Western Australia, about 80 km (50 mi) south of Perth.
The Peel Main Drain is a drainage canal in the southern suburbs of Perth, Western Australia. Construction of the canal commenced in 1920 to drain the wetlands in the area as part of the post-World War I Group Settlement Scheme at the Peel Estate. The canal stretches from Banjup, where it starts just north of Banjup Lake, to Karnup, where it discharges into the Serpentine River. The drain has a catchment area of 120 square kilometres.
Peel-Harvey has traditionally been seen as one estuary. However, the Water and Rivers Commission of WA has now classified it as two separate estuaries (Peel Inlet and Harvey Estuary) so that each one is linked to the River Basin from which it drains.
