Lake Erie North Shore Watershed Plan - Niagara Peninsula ...

LAKE ERIE NORTH SHORE WATERSHED PLAN
Physiography
The physiographic region of the Lake Erie North Shore watershed is the Haldimand Clay
Plain which extends from the Niagara Escarpment to Lake Erie. The Haldimand Clay
Plain was submerged by post-glacial Lake Warren and much of it is covered by
lacustrine clay deposits; although not all till was covered such as the till moraine in
Lowbanks.
Underlying rocks consist of a succession of Palaeozoic beds dipping slightly southward
under Lake Erie (Chapman & Putnam 1984). Soft shales have been worn down in front
of the hard limestone Onondaga Escarpment, forming a large depression. The
overburden of soil materials increases southward from the Niagara Escarpment to a
thickness depth nearing 45 meters over the wide buried bedrock valley called the Erigan
Valley north of the Onondaga Escarpment. The Erigan Valley extends in a
southwestwardly orientation from Fonthill towards Lake Erie cutting through the
Onondaga Escarpment in the Moulton Bay area (Armstrong 2007). Southward of the
Onondaga Escarpment, overburden remains relatively thin, ranging in thickness from 3
meters up to 15 meters near the shoreline.
North of the shoreline, just west of Shisler Point and extending east to Crystal Beach, a
long lacustrine beach of Lake Warren in the form of a gravel elongated mound is visible.
Several other smaller remnants have been identified throughout Welland and Wainfleet.
According to Chapman and Putnam (1984), these gravel bars are seldom over six or
eight feet deep.
The physiography of the Lake Erie North Shore is illustrated on Figures 6a and 6b.
Onondaga Escarpment
The partially-buried Onondaga Escarpment runs in an east-west orientation along the
southern edge of the Niagara Peninsula. In Ontario, the Onondaga Escarpment extends
from Hagersville to Fort Erie, and then continues into New York. The relatively low
feature is capped by the Bois Blanc formation of the Devonian System, a very hard
fossiliferous limestone. There are small outcrops of bedrock along the crest of the
Onondaga Escarpment (Brady 1980). As previously mentioned, except for a few small
watercourses, this ridge prevents drainage south to Lake Erie; north of the Onondaga
Escarpment water is forced to drain north and east with the low lying areas remaining
flooded. South of the Onondaga Escarpment, water drains directly to Lake Erie.
Lake Erie Shoreline
The Lake Erie Shoreline Management Plan (Philpott Assoc.1992) reports that the entire
Lake Erie shoreline from Port Ryerse, just west of Port Dover, to the Niagara River lies
within one littoral cell with a net direction of littoral drift from west to east under prevailed
westerlies. Possible sources of littoral material include bluff erosion, stream discharge,
and nearshore lake bottom erosion. The western portion of the shoreline can be
characterized by high glacial till bluffs while east of Moulton Bay and the remainder of
the shoreline consists of low glacial till bluffs with bedrock outcrops anchoring pockets of
sand and shingle beaches. The backshore consists of either a low drift or a dune
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