Question: Willawilla is part of a watercourse that drains in to an area known as what?

Context paragraphs:
Ishëm (river): The Ishëm (or "Ishmi") is a river in western Albania, which brings water to the area north of the Albanian capital, Tirana.  It forms part of a watercourse (Tiranë-Gjole-Ishëm), but only the lower third of the watercourse is known as the Ishëm.  The Ishëm proper is formed at the confluence of the rivers Gjole and Zezë, a few km northwest of Fushë-Krujë.  It flows into the Adriatic Sea near the town Ishëm.  The length of the watercourse is recorded in different sources as between 74 and 79 km.

Patawalonga River: The Patawalonga River is a river located in the western suburbs of the Adelaide metropolitan area, in the Australian state of South Australia.  It drains an area of flat, swampy lands formerly known as the Cowandilla Plains, which in the mid-20th century were drained by engineering works, enabling the establishment of Adelaide Airport and the development of residential housing.

Small's Creek: Small's Creek was one of the three watercourses that flowed into Small's Pond, a small body of water of several acres in area, located near the intersection of Queen Street and Kingston Road.  There is a small plain between the shore of Lake Ontario and the bluffs which marked the shore of the larger Glacial Lake Iroquois, Bedrock was shallow on the plain.  Smalls Creek, Tomlin's Creek, the other watercourse that drains into Smalls Pond, and Ashbridge's Creek to the east were all small, short watercourses, with their headwaters on that small plain, had each become polluted by the turn of the 20th century, when the regions they flowed through were annexed into the growing city of Toronto.

Nura River: The Nura River (Kazakh: Нұра ; Russian: Нура ) is a major watercourse of northeast-central Kazakhstan.  It is about 978 km long and drains an area of 58100 km2 .

Mount Cramer: Mount Cramer, at 10716 ft is the second highest peak in the Sawtooth Range of Idaho.  The summit of Mount Cramer is located on the border of Custer and Boise Counties.  The peak is the highest point in Boise County.  Mount Cramer is also located within the Sawtooth Wilderness portion of the Sawtooth National Recreation Area.  The town of Stanley, Idaho is almost 14 mi from Mount Cramer, while the area known as Sawtooth City is nearly 12 mi from Mount Cramer.  The west side of Mount Cramer drains into the South Fork of the Payette River, while the east side drains to the Salmon River.

Yellow House Draw: Yellow House Draw is an ephemeral watercourse about 236 km long, heading about 20 km southwest of Melrose, New Mexico, and tending generally east-southeastward across the Llano Estacado to the city of Lubbock, where it joins Blackwater Draw to form Yellow House Canyon at the head of the North Fork Double Mountain Fork Brazos River.  It stretches across Roosevelt, Curry, Bailey, Cochran, Hockley, and Lubbock counties of eastern New Mexico and West Texas, and drains an area of 9790 km2 .

Brown Hill Creek: The Brown Hill Creek, also known as Willawilla in the Kaurna language, part of the Patawalonga River catchment, is a watercourse located in the western suburbs of the Adelaide metropolitan area, in the Australian state of South Australia.

Wimmera River: The Wimmera River, an inland intermittent river of the Wimmera catchment, is located in the Grampians and Wimmera regions of the Australian state of Victoria.  Rising in the Pyrenees, on the northern slopes of the Great Dividing Range, the Wimmera River flows generally north by west and drains in Lake Hindmarsh and Lake Albacutya, a series of ephemeral lakes that, whilst they do not directly empty into a defined watercourse, they form part of the Murray River catchment of the Murray-Darling basin.

New Hope Creek: New Hope Creek is a watercourse that rises in rural Orange County, North Carolina, in the United States.  It drains the western portion of Orange County and the southern half of Durham County and flows into the northern end of Jordan Lake reservoir.  The drainage area encompasses urban, suburban and rural lands.  Formerly the New Hope River, it was a tributary of the Cape Fear River until it was dammed to create Jordan Lake.  Construction of the lake began in 1973, after a comprehensive study of regional water management by the U.S. Army Corps of Engineers, motivated by major flooding in a 1945 hurricane.  Several communities draw drinking water from Jordan Lake, increasing interest in protection of the New Hope Creek watershed.

Arroyo Corte Madera del Presidio: Arroyo Corte Madera del Presidio is a 4.1 mi year-round stream in southern Marin County, California, United States.  This watercourse is also known as Corte Madera Creek, although the actual stream of that name flows into San Francisco Bay further north at Point San Quentin.  This watercourse has a catchment basin of about 8 sqmi and drains the south-eastern slopes of Mount Tamalpais and much of the area in and around the town of Mill Valley; this stream discharges to Richardson Bay.

Supporting paragraphs: Brown Hill Creek Patawalonga River
Answer: Cowandilla Plains