In 2006 artist Ledia Carroll outlined Lago Dolores or Mission Lake in the Mission District of San Francisco which disappeared when the neighborhood was built in 1776.
I have had the idea to trace an outline of the Riviere Saint Pierre which once flowed through Turcot Yards. Of course Otter Lake could also be outlined. If anyone wants to give this a try, please email me at neathatturcot@yahoo.ca
Or we could also ask Nicole Dextras to help re-create a frozen river or lake we could all skate away on.
PostArctica 
Were these bodies of water drained or dammed elsewhere so the yards could be built over them?
I believe the lake was probably drained though the river may have been “culverted ” somehow. Although there is talk of Turcot once having been a swamp- https://neath.wordpress.com/2006/08/14/mystery-at-otter-lake/