Sydney River rises in Blacketts Lake and runs 12.5 km (7.8 mi)[dubious – discuss] to its mouth, between the Westmount shore near Amelia Point and Battery Point on the Sydney shore,[1] at the South Arm of Sydney Harbour, draining a watershed of 140 km2[5]: 6 south of the crest of the Coxheath Hills. The river is an estuary for the last 7 km (4.3 mi) below the "Sysco Dam" in the community of Sydney River. The dam was constructed in 1902, converting the stretch of river immediately above the dam from a tidal estuary to a freshwater reservoir lake.[5]: 6 Its watershed contains more than 2000 homes.[2]
The Sydney River valley is glacial with thick deposits, kames, eskers and outwash gravels creating a series of shallow lakes connected by narrow channels. This low valley was a traditional canoe portage used by the Mi'kmaq for travelling between Sydney Harbour and the East Bay of Bras d'Or Lake.[6] The river is one of only two Canadian watersheds with a known population of the yellow lampmussel.[2] The lampmussel is found above the dam constructed in 1902,[5]: 6 which increased the area of freshwater habitat suitable for lampmussel in the watershed.[5]: 8
^ abcdFisheries and Oceans Canada (2010), "Management Plan for the Yellow Lampmussel (Lampsilis cariosa) in Canada [Final]", Species at Risk Act Management Plan Series(PDF), Ottawa: Fisheries and Oceans Canada