Location: This sub-watershed is located entirely within Tay Valley Township formerly the wards of Bathurst Burgess and South Sherbrooke (Lanark County). Human development is centred in the village of Bolingbroke and cottage lots surrounding the lakes. This area extends from the Bobs Lake dam near Bolingbroke to the Tay River inflow at Christie Lake. Included in this sub-basin are Davern, Farren, Little Silver, O’Brien Lakes, and the Tay River.
Drainage Area: 3628 ha.
Geology: The entire sub-watershed is underlain by relatively unfertile Precambrian rock of the Frontenac Axis. Known as the Frontenac Terrane, this area consists of paragneiss, quartzofeldspatic gneiss, quartz arenite, calcite and dolomite marbles. These Precambrian rocks are highly folded and faulted with a major northeast/southwest tectonic trend all tilting to the southeast.
Land Use: Agricultural practices represent a small portion of the land use (0.8% crop and 3.0% pasture) within the area. The Shield Forest that is endemic to the area is well maintained (69.6%). Successional lands (5.4%), wetlands (9.4%), and lakes (11.9%) compose the remaining land use area. The Christie Lake wetland (non-provincially significant) exists in the eastern portion of this sub-basin where the Tay River meets Christie Lake.
Community: Davern Lake supports a diverse cool water community consisting of smallmouth bass, largemouth bass, northern pike, yellow perch, pumpkinseed, crappie, cisco (lake herring), and white sucker. No stocking has taken place since rainbow trout and smallmouth bass were stocked in the 1950’s.
Farren Lake contains a cold water community including splake, smallmouth bass, largemouth bass, cisco (lake herring), yellow perch, rock bass, brown bullhead, and various species of panfish. The lake has a lengthy history of stocking bass, lake trout, rainbow trout, and splake form the 1920s to the present. Currently, Farren is stocked on an annual basis with approximately 5000 yearling splake.
A warm water fish community is present in Little Silver Lake including fish species such as largemouth bass, smallmouth bass, yellow perch, pumpkinseed, bluegill, brown bullhead, yellow bullhead, and white sucker. Walleye were stocked into Little Silver Lake in 1971, 1972, and 1992, however a naturally reproducing population was not established.
This reach of the Tay River (from Bobs Lake dam to Christie Lake) supports a diversity of warm water fish species. Smallmouth bass, largemouth bass, northern pike, yellow perch, pumpkinseed, bluegill, and whiter sucker all inhabit the Tay River. This segment of the Tay River supports a resident walleye population, as well as a migratory population of walleye from Christie Lake, which utilize the area as spawning habitat during the spring.
Issues: Many controversial issues are ongoing in this sub-watershed. On Davern Lake, a conflict between cottage owners and landowners over water level has occurred in the past. Davern Lake cottage owners complain that the water levels are too high; flooding property and submerging docks, while the landowners downstream are attempting to protect their properties from early season floods.
A water level control structure was installed to minimize seasonal water level fluctuations on Little Silver Lake. It is believed that this control structure has decreased the lakes flushing rate, causing increased sedimentation and eutrophication. The Little Silver Lake Cottage Association has repeatedly requested the OMNR establish a walleye fishery on Little Silver, which is in contrast to OMNR’s fisheries management planning for the lake. Walleye stocking has previously failed to create a naturally reproducing population on three separate attempts in 1971 and 1972, and recently in 1992. Lack of suitable spawning habitat is sited as the limiting resource, since the lake does not have an inflow or accessible outflow drainage and the lake is too small to support a self sustaining shoal spawning walleye population. For these and many other social and biological reasons, the lake remains managed as a warm water bass fishery.
Farren Lake has historical issues surrounding cottage development. The lake has a history of relatively unsuccessful stocking, possibly due to high rates of interspecific competition within the fish community and high angling pressure.
This reach of the Tay River is an area with conflicting resource user groups. Issues in this location revolve around beaver dam obstructions, and water fluctuations from the dam at Bobs Lake.
Information: This area is under the jurisdiction of the Kemptville District OMNR. Extensive information has been collected on all lakes in the form of lake inventories, creel census, and netting programs. The RVCA and OMNR have recently conducted several hoop netting studies, benthic invertebrate and water quality sampling, walleye spawning bed surveys, and stream habitat classification on this reach of the Tay River.
Maps: Figure 2.4.1- Critical fish habitat and enhancements site on Davern Lake.
Maps: Figure 2.4.2- Critical fish habitat of Farren Lake.
Maps: Figure 2.4.3- Critical fish habitat of Little Silver Lake.
Maps: Figure 2.4.4- Critical fish habitat and enhancement sites on the Tay River (Bobs Lake to Christie Lake).
Fish Habitat Summary: T4 - Davern, Farren, Little Silver Lakes, and the Tay River
General trends indicate stable Secchi disk and nutrient levels
Low flushing rate
DO / temperature profiles of the lake indicate good oxygen levels with DO depletion in deep waters in summer months
Practices that decrease nutrient and sediment loading should be followed (ie. shoreline rehabilitation, restrict livestock assess, monitor cottage septic systems, etc.)
Shoreline rehabilitation projects exist on the east shore (only developed shoreline of the lake) and on the northern shoreline near the railway bed (Figure 2.4.1)
Critical Fish Habitat
Anecdotal evidence suggests that smallmouth bass fishing on Davern Lake has improved possibly due to increased available spawning habitat for Centrarchids and pike with higher water levels
Bass are known to spawn in all shallow, sandy, near shore areas around the lake
Concentrations of bass nesting and pike spawning locations are found in the south portion of the lake near the outlet (Figures 2.4.1, 2.4.5)
Bass spawning (nesting) and rearing areas should be strictly protected from development in or near water, and early summer (preseason) angling pressure
Water levels should be maintained to provide adequate bass and pike spawning habitat but not to flood cottage lots
Lake / Watercourse
Fish Community Objective
Existing Fish Habitat Conditions
Fish Habitat Enhancement Opportunities
Farren Lake – T4
Cold water with top predators such as splake, smallmouth and largemouth bass
Splake population maintained through stocking of 5 000 yearlings/ year
Other populations are natural and self-sustaining
Trophic State- oligotrophic
Average phosphorus level in 1997 was 0.008 mg/l, which is below the PQWO of 0.01mg/L
DO/temperature profiles indicate good oxygen levels, although DO depletion in deep waters resulting from phosphorus regeneration from lake sediments is a problem in the summer months
Secchi disk, chlorophyll, and phosphorus measurement trends indicate improving water quality
Practices that decrease nutrient and sediment loading should be strictly followed (ie. shoreline buffers, restrict livestock access, monitor cottage septic systems, etc.)
Many cottage lots particularly on the south shore and the permanent residences on the northwest shoreline near the access point (Figure 2.4.2) exhibit riparian degradation and shoreline hardening