7.0 Port Elmsley Catchment: Challenges/Issues
Headwater and tributary streams in the Port Elmsley catchment have 40 percent of the total length of their shoreline composed of natural vegetation. This is below the 75 percent target that is recommended by experts for the catchment’s watercourses, 30 metres back from both sides of a stream, river or lake (see Section 4.4 of this report).
Thirteen of 19 sampled headwater stream sites have been modified (10 are channelized, 3 are ditched; see Section 3.4.2 of this report).
Land cover has changed across the catchment (2008 to 2014) largely as a result of an increase in the area of settlement (23 ha.) and wetland (12 ha.) and loss of crop and pastureland (20 ha.) and woodland (12 ha.)(see Section 4.1 of this report).
Wetlands have declined by fifty-five percent since European pre-settlement and now cover 20 percent (1033 ha.) of the catchment (in 2014). Forty-seven percent (482 ha.) of these wetlands remain unevaluated/unregulated and although they are not under imminent threat from development activity, they do remain vulnerable to drainage and land clearing activities in the absence of any regulatory and planning controls that would otherwise protect them for the many important hydrological, social, biological and ecological functions/services/values they provide to landowners and the surrounding community (see Section 4.3 of this report).
Woodlands cover 20 percent of the catchment. This is below the 30 percent of forest cover that is identified as the minimum threshold for sustaining forest birds and other woodland dependent species ( see Section 4.2 of this report) .
The Tay River through the Village of Port Elmsley has a history of ice damming that has resulted in overland flow through the Pointview subdivision, between the Tay River and Lower Rideau Lake.
Stream flow (high, low and base) is unrecorded and water level is measured with a manual staff gauge at the Beveridges Dam along this reach of the Tay River in the Port Elmsley catchment. .
Surface chemistry water quality rating along the Tay River in the Port Elmsley catchment is Good at the Tay Marsh and Village of Port Elmsley monitoring sites . No apparent water quality concerns are reported for this reach of the Tay River ( see Section 2.1 of this report).
Instream biological water quality condition in the Tay River is Fair at the Port Elmsley Road crossing . S amples shift from benthic invertebrate species that are sensitive to high organic pollution levels in the fall to species that are more tolerant of those high levels in the spring (see Section 3.3.1 of this report).
The Town of Perth wastewater treatment facility is located on the south side of the Tay River, adjacent to the Tay Marsh. The outflow from the Perth sewage lagoons has impacted water downstream for decades. Outflow quality has, on the average, been within provincial limits, but inevitably has had an impact on the Tay Marsh and is one of (many) sources encouraging excessive vegetation growth in the wetland, which damages its fish and wildlife habitat (per.comm.FoTW).