 
		 
		 
		Plan of Philadelphia, John Hills, 1796
 
		Frankford Creek Watershed: A historical overview of the Philadelphia section
 
		Frankford Creek Watershed Historical Timeline
 
		Drawing Dock Creek
 
		Overbrook, as it was. A brief history of the Overbrook neighborhood of Philadelphia, focusing on changes in the natural landscape.
 
		Cobbs Creek: A Brief Historical Overview by Adam Levine
 
		Centre Square Water Works, Drawings of Intake Basin
 
		Centre Square Water Works, Frederick Graff, Sr. Plans, 1799
