Question: Brown Hill Creek is part of what river that drains an area of swampy lands formerly known as the Cowandilla Plains?

Context paragraphs:
History of Plymouth, Pennsylvania: Plymouth, Pennsylvania sits on the west side of Pennsylvania's Wyoming Valley, wedged between the Susquehanna River and the Shawnee Mountain range.  Just below the mountain are seven hills that surround the town like the Hills of Rome, and form a natural amphitheater that separates the town from the rest of the valley.  The hills are named Avondale Hill (or Reynolds Hill), Curry Hill, Turkey Hill (or Cemetery Hill), Levi's Hill, Welsh Hill, Pierce Hill (or Shonk Hill), and Ross Hill.  Eight creeks run between the hills down to the river.  These are Harveys Creek, Jersey Creek, Coal Creek (formerly Mill Creek, Smith's Creek or Ransom Creek), Wadham's Creek (formerly Whittlesey's Creek), Brown's Creek (formerly Nesbitt's Creek, Cooper's Run or Pine Swamp Creek), Shupp's Creek, and Toby's Creek.  Below the hills, the flat lands are formed in the shape of a frying pan, the pan being the Shawnee flats, once the center of the town's agricultural activities, and the handle being a spit of narrow land extending east from the flats, where the center of town is located.

Crafers West, South Australia: Crafers West is a suburb of Adelaide in the Adelaide Hills Council.  It was formally named in 1985 as a separate address from Crafers.  Crafers West contains the headwaters of Brown Hill Creek and is dominated by steep terrain and native scrub.  It is bounded by Mount Barker Road on the northeast and the Bridgewater railway line on the south.  The Eagle Mountain Bike Park is in the north of the suburb.

Electoral district of Waite: Waite is an electoral district of the House of Assembly in the Australian state of South Australia.  Named after Peter Waite, a 19th entrepreneur and philanthropist in the current area of the electorate, it is a 33.1 km² urban electorate in Adelaide's inner south-east, taking in the suburbs of Brown Hill Creek, Clapham, Hawthorn, Kingswood, Lower Mitcham, Lynton, Mitcham, Netherby, Panorama, Pasadena, Springfield, St Marys, Torrens Park, Urrbrae and Westbourne Park as well as parts of Belair, Colonel Light Gardens, Daw Park and Leawood Gardens.

Brown Hill, Mitcham: Brown Hill is a hill in the Australian state of South Australia located on the western edge of the Mount Lofty Ranges, 7 km southeast of the centre of Adelaide, in the suburb of Brown Hill Creek.  Brown Hill rises to 312 m above sea level.

Brownhill Creek Recreation Park: Brownhill Creek Recreation Park is a protected area located about 8 km south of the Adelaide city centre in City of Mitcham along part of the course of the Brown Hill Creek.  The recreation park was proclaimed under the "National Parks and Wildlife Act 1972" in 1972 to "provide recreation opportunities for the Adelaide and eastern metropolitan region and to conserve remnant aged river red gums and the riparian zone habitat".  The land previously subject to protected area status as a "National Pleasure Resort" since 1915.  The recreation park is classified as an IUCN Category III protected area.

Tomichi Creek: Tomichi Creek is a 71.8 mi tributary of the Gunnison River in Gunnison County, Colorado.  Tomichi Creek originates north and west of Monarch Pass and flows to the southwest along the base of Monarch Mountain.  Congress Creek drains into Tomichi west of Old Monarch Pass where it flows south toward Sargents.  Agape Creek flows into Tomichi just north of Sargents where Marshall Creek flows from Marshall Pass.  Just below Sargents, Long Branch Creek, flowing out of Baldy Lake from the south, enters Tomichi Creek which takes a westward course where Needle Creek Reservoir drains into Tomichi east of Doyleville.  Hot Springs Reservoir drains down Wanita Canyon flowing into Tomichi Creek just west of Doyleville.  The Tomichi Valley is a semi-wide valley allowing Tomichi Creek to meander and split into several waterways creating an excellent livestock range and being largely private ranch lands.  At Parlin, Quartz Creek flows from Pitkin and Ohio into Tomichi Creek.  Tomichi continues its westward journey, slightly northwest, where the Cochetopa Creek drains into Tomichi at State Highway 114 from the south at the intersection of U.S. Highway 50 and continues west to Gunnison where it enters the Gunnison River.  A map can be viewed at the BLM Colorado website here.

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.

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.

Brown Hill Creek, South Australia: Brown Hill Creek is a south-eastern suburb of Adelaide in the City of Mitcham in South Australia, named after the eponymous Brown Hill Creek.

Sideling Hill Creek (Potomac River): Sideling Hill Creek is a 25.2 mi tributary stream of the Potomac River in the U.S. states of Maryland and Pennsylvania.  Sideling Hill Creek flows southward along the western flanks of Sideling Hill, from which the stream takes its name.  It forms the boundary between Allegany and Washington counties in Maryland.

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