Changes in the Emergent Plant Community of Netley-Libau Marsh ...

Grosshans et al.
Vegetation change in Netley-Libau Marsh
Figure 13. This oblique, aerial view (looking southwest) of the Red River, Netley Cut, and Netley Lake was
taken on 8 October 2003. The mouth of Netley Creek at the Red River is visible in the background. Low
water levels in Netley-Libau Marsh and Lake Winnipeg in 2003 revealed sedimentary deposits northwest of
Netley Cut that were presumably deposited by the Red River flowing into the marsh. Vegetation colonization
of these newly exposed areas was rapid but the plants were inundated again in 2004 (Appendix 5).
are eroded or collapse. These extreme flow events
on the Red River are likely to have had an impact on
the levees and uplands of Netley-Libau Marsh.
The nature of river flow through Netley-Libau
Marsh has been modified by humans for at least a
century. For example, water flows from the Red
River into the southeastern corner of Netley Lake
through a breach in a narrow strip of upland
between them (Figure 13). The so-called Netley Cut
was excavated by the federal government in October
1913 (Library and Archives Canada, Winnipeg,
Accession W84-85/493 Box 26 Netley). The
excavation was justified as providing a means for
water entering Netley Lake during wind set-up on
Lake Winnipeg to exit more quickly and drain
valuable hayfields. At that time, it apparently did not
do so under normal conditions. It would also enable
boat access by local residents wanting to collect
cordwood and hay on the shores of Netley Lake.
(The cut through the east bank of the Red River to
the Devil’s Lake portion of Netley-Libau Marsh –
Figure 6 – had apparently been dredged prior to
1907.) Erosion of the Cut began almost immediately
and became a recurring problem for government
engineers. A small bridge, constructed to enable
farmers to reach an estimated 445 hectares of hay
land north of the channel, washed away in 1916. A
sheet pile dam was built across the Cut during the
winter of 1919-20 but it (and an associated bridge)
was damaged by the summer of 1920. By 1924, the
channel was over 24 m wide and averaged about
5 m deep. During replacement of the dam that year,
the hull of a former river dredge that had been
moored lengthwise across the channel to support a
pile driver, sank and was abandoned, ostensibly to
form part of the dam and a makeshift bridge. The
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