The "Petticoat Creek watershed is dominated by the South Slope physiographic region, a smooth, faintly drumlinizedtill plain."[4]
Because the creek is not long enough for its headwaters to lie within the groundwater rich Oak Ridges Moraine, waterflow on the upper reaches is intermittent and dependent on precipitation.
Lower reaches, below the ancient shoreline of glacial Lake Iroquois, is more consistent.
Petticoat Creek Conservation Area
The Petticoat Creek Conservation Area is located at the mouth of the creek at Lake Ontario,[5] and is managed by the Toronto and Region Conservation Authority after the Petticoat Creek Conservation Authority was absorbed in the TRCA.
^TRCA Watershed Action Plan, 2012, 2.1 Watershed Perspective, p. 10. "Today, Petticoat Creek watershed represents a continuum between natural, rural and urban land uses and is best described as an urbanizing, warm-water nude system. Natural and rural areas of the watershed, comprising roughly two-thirds of the land base, are protected under selected provincial initiatives, explained below. The long history of agriculture in this area has not resulted in significant degradation of the northern portion of the watershed. The agricultural community has generally been a good steward of this land."
^"Petticoat Creek". Toronto and Region Conservation Authority. 2013. Archived from the original on 2014-06-29. Retrieved 2018-07-03.
^TRCA Watershed Action Plan, 2012, 2.8 Terrestrial System, p. 37. "Historically, the watershed would have been predominantly covered in forest and wetlands. Over time this natural cover, along with its environmental benefits, was diminished by human activity to what is now considered below the desired level. Today, natural cover in the form of forests, wetlands, and meadows is concentrated in public greenspace areas:"
