By Earl Patric

Earl Patric 1928-2011

We have been privileged to have the expertise of Earl Patric (Pat) for many years.  We will miss him both as a friend and as supporter of wildlife and the ecosystem of Lower Beverley Lake.  His knowledge of environmental issues and the science behind them has been a source of information for LBLA.  Over the years he has given us many writings regarding the lake and what he sees as the issues we should be concerned about.  As we get them organized, we will post them.




Written by Earl Patric

Updated 6/2011




When the Wisconsin glacier receded from our area ten to eleven-thousand years ago, it scooped out a depression in the local limestone-laden rock which would become the water body we now know as Lower Beverley Lake (earlier known as Gananoque Lake). With the passage of the centuries, a productive fauna and flora developed, supported by rich soils and adequate rainfall. The lake remained relatively unchanged until the arrival of European explorers and settlers. It was then only about three-fourths its present size, both in area and depth. Its natural watershed area was almost exactly the same size as today’s, namely 26,000 H or 64,200 A.* The early lake had four inlets, of which the Morton Creek inlet was the largest.  It had only three islands: what are now Prisoner’s, Whiskey, and Aird.With the arrival of local settlers, the lake was altered. Dams were erected where hydropower could drive flour mills, iron foundries, and saw mills. A dam at Lyndhurst raised the water level substantially, and in the early 19th century the water level of Lower Beverley Lake was determined largely by milling requirements and weather.When the Rideau Canal system was opened in 1832, another important impact was felt on Lower Beverley Lake. Lt. Colonel John By, the canal designer and builder, provided “for the possibility that the Rideau Waterway might be getting too much water” and arranged for an “overflow or spillway dam at Morton… which serves as a ‘safety valve’ to the system…”, allowing excess water to move “down Morton Creek into Lower Beverley Lake and eventually into the St. Lawrence by way of the Gananoque River.” (Legget, 1955). Thus, while the natural watershed of the Lake remains at 26,000 H* or about 100 square miles, the practical watershed is now reduced. This places a further burden on the dam at Lyndhurst, which must handle stream flow well beyond its natural watershed yields. Morton Creek has become a minor inlet to the Lake, whereas its original position was nearly equal to that from Upper Beverley Lake. In addition, the Morton Creek flow is the most erratic, based primarily on the vagaries of weather and the dam management practiced by Parks Canada at Morton.By the early 1900s water power was being replaced by other power sources, and the dam at Lyndhurst fell into disrepair. At the same time tourism and lakeside cottages were growing in importance, and a more forceful demand for increased and more stable lake levels prevailed. This demand resulted ultimately in the construction of the present dam at Lyndhurst by the Ontario Ministry of Natural Resources, with the first effective operation in June, 1960.* for this document M = meters, A = acres, H = hectares, LBL= Lower Beverley Lake2. PHYSICAL CHARACTERISTICSThe following statistics presume normal summer lake levels with water flowing over the spillways at Lyndhurst with five and one-half logs in place. Figure 1 presents a 1:50,000 map of the Lake. Figure 2 provides the best available but none-too-accurate bottom contours of the Lake.

  • Lake Locator: Lat. 44° 36 N, Long. 076° 08 W.Area- 770 H (1,900 A)
  • Maximum Depth: 28.7 M (94 ft.)
  • Mean Depth: 9.1 M (30 ft.)
  • Surface Elevation: 91.85 M (301.3 ft.) above mean sea level
  • Lake Volume: 70 million M (56,904 acre-feet)
  • Perimeter: 44 km. (27.3 miles)
  • Significant Islands: 14



The following statistics are based on the natural watershed of the lake, without the complication of the Rideau Waterway. Figure 3 depicts the boundaries of the natural watershed.

  • Area of Watershed- 26,000 H (64,220 A or about 100 sq. miles)
  • Estimated Lake and Pond Surface in Watershed- 1,377 H (3,400 A)
  • Theoretical Discharge from 2.5 cm. (one inch) Rain Event- 6.5 million M3 (5,330 acre-feet)
  • Theoretical Discharge from Normal Annual Rainfall (assumes one meter or 39.4 inches per annum)- 260 million M3
  • Theoretical Average Discharge Per Hour- 29,680 M3 (24.1 acre-feet)


Most of these data are extracted from a limnological survey conducted by the Ontario Ministry of Natural Resources in July, 1971.

  • Position of Thermocline (zone of maximum temperature change) – five to nine meters of depth
  • Dissolved Oxygen Above Thermocline – 9 ppm
  • Dissolved Oxygen Below Thermocline – 2 ppm
  • Surface Temperature – 21 C. (72 F.)
  • Bottom Temperature – 10 C. (49 F.)
  • pH – 7.6
  • Dissolved Solids – 185 ppm
  • Normal Month of Overturn – Spring, April; Fall, November
  • Turbidity – secchi disc disappeared at 2.55 M (8.5ft.)

The reader is referred to recent minutes of LBL Association general meetings for a lengthy sequence of turbidity measurements.



The watershed is underlain by the rock of the Canadian Shield, some of the oldest rock on the planet. In many areas, and especially around the lakes, a layer of limestone of more recent origin prevails. With a growing season usually well over 100 days and adequate rain fall, some fairly productive soils have developed. These soils, like the lake, are slightly basic in pH; their primary shortcoming from an agricultural standpoint is that they possess rather a high clay content, and do not permit early crop starts. Nonetheless, they can and do support a productive and diverse biota.

Prior to settlement the region was entirely forested, with trees and shrubs of many species. The zone is often referred to as a Transition Forest because there is some representation of the northern “Taiga” forests of the north (spruce, fir, paper birch, etc.) mixed with tree species (oaks, basswood, walnut, hickory, etc.) usually associated with regions further to the south.

Beginning in the early 19th century the forests were cleared for agriculture, probably resulting in well over 90% of land suitable for tillage cleared of tree cover. A vigorous and diverse agriculture developed, and even a small acreage could provide a decent living for a family. However, by the early 20th century large and highly mechanized farming, usually further west, began to make small-acreage agriculture in the area an unattractive option, and abandoned croplands began to revert to forest

At the present time, about half the Lower Beverley Lake watershed is forested and continued reversion will increase forest representation for the foreseeable future. Fortunately, at this time, this mix of hardwood and softwood forests, wetlands, water bodies, and open land provides excellent habitat for wildlife, and a most agreeable environment for vacationer, retirees, and local residents.



The following comments must be confined to very general and somewhat superficial observations, with the listings further confined to the larger animals. They are based on Toner (1938), Hughes (2001), and interviews with Mr. Thomas Beaubiah of the Cataraqui Region Conservation Authority and Mr. Scott Smithers of the Ontario Ministry of Natural Resources.


  • Marsupials – the opossum is very rare
  • Carnivores – raccoons and skunks are common; fishers, mink, weasels, otters, red fox, and coyotes are occasional; black bears, coyotes, bobcats are rare. Pine marten, gray fox, lynx, and badger are not found in the watershed. Some coyotes may possess wolf DNA.
  • Rodents – woodchucks, red and gray squirrels, beavers, muskrats, and porcupines are common.
  • Lagomorphs – varying hare and cottontail rabbits are occasionally seen.
  • Artiodactyls – white-tailed deer are common. Moose are rarely seen, and when seen are traveling through.


There are 473 bird species recorded in Ontario, of which 288 species are known to breed in the Province. We suspect that well over 200 species occur and breed within the watershed. The reader is referred to an excellent and recent reference by Hughes (2001) for additional ornithological information.


In 1938 Toner published the results of a well-executed “Biological Survey” of Lower Beverley Lake. This author had reason to believe that “about 50 to 60 years ago whitefish, herring, and lake trout were plentiful” but they had subsequently vanished. At the time of his survey 29 fish species were identified, of which small and largemouth bass and northern pike were most notable from a sport fisher’s standpoint In an interesting aside Toner notes that “pollution in lower Beverly [sic] lake is limited to the dumping of sawdust in the creeks at Delta and at Morton.” The Ontario Ministry of Natural Resources conducted a somewhat less detailed and intensive survey in 1971. Its report identified 19 fish species in the Lake, with the same three predominant sport fish. One clear fact that emerges is that sport fishing remains excellent in Lower Beverley Lake. Despite heavy fishing pressure, the success rate is very good to excellent An annual testimony to this fact can be seen on the bulletin board at Wing’s Bait Shop in Lyndhurst.



At the present time there is an excellent mix of plant and animal species occurring on diverse and interspersed open lands, forests, wetlands, and water bodies. Those soils which have developed on limestone support a luxuriant and rapidly-growing vegetative community.  For the upland hunter, deer, raccoon, partridge, squirrels, hare, and rabbits occur in very adequate numbers, and there is a brief and somewhat limited water fowling opportunity. For the photographer, hiker, camper, nature lover, etc. there seem to be abundant attractions.

On the natural watershed lands of Lower Beverley Lake over-development has not yet occurred, and there are too few housing starts on most of the watershed to suggest that over-development is imminent. Some sections of the lake shoreline are rather intensely developed; on the other hand, there are shoreline areas which are totally undeveloped.

Unfortunately, lake levels continue to vary more than most lakeside dwellers and lake users would like. As mentioned under the topic of “Physical Characteristics” the natural watershed is a rather large 100 square miles and the true watershed which involves a part of the Rideau Waterway may make the effective watershed close to 150 square miles. This makes effective water runoff management a difficult task. Another problem is that most soils possess a high clay content and do not permit much of the normal rainfall to percolate down through the soil to the water table. Perhaps 20-30% of total rain is intercepted by vegetation, evaporated from surfaces, or soaked into the soil. All of the remaining rain volume must therefore be handled by the Lyndhurst Dam. This constitutes a challenging array of dam management issues, when one considers that flood control and electric power generation concerns must also be weighed.

Parks Canada is responsible for dam management at Morton and the Ontario Ministry of Natural Resources is responsible for dam management at Delta (regulating Upper Beverley Lake) and Lyndhurst In relation to the Lyndhurst dam management policies there exists a document entitled “Operating Guidelines” prepared by MNR. These guidelines have no known contractual obligations, but provide water resource technicians with some procedural direction. In general the guidelines call for the Lyndhurst dam to set lake levels at 91.85 M above mean sea level after the spring runoff, through summer, to “near mid-October”. After mid-October the dam logs are reset to create a lake level of 91.70 M above mean sea level. After extraordinary rain events it is understood that adjustments must be made to control flooding. At this writing the influence of electric power generation interests on dam management practice is small.

It should be kept in mind that because the watershed is a natural Transition Forest, there are some plant and animal species living at the northern and southern extremities of their range. These species are often scarce or uncommon, and failing to flourish as they might closer to the middle of their ranges. This is a very normal condition, and should not necessarily be interpreted as “endangered” or near “extinction”. Of course, some plants and animals may, in fact, be correctly classified in these categories.

As agricultural land continues to be abandoned, the watershed will be increasingly forested. Whether this is desirable or undesirable is a matter of opinion and preference. Nonetheless, it can be forecast with some certainty that the biota of the future will be less diverse than now prevails, because the presence of open and reverting habitats will be much reduced.



These are not intended to be set forth in priority order:

Current Problems

  • Continued shoreline development will ultimately degrade the quality of the lake environment.
  • Lake water levels continue to be excessively variable, and dam management personnel may be stretched too thin or distracted to other concerns to adhere fully to the Operating Guidelines.
  • Noise pollution is a growing problem. It results from larger numbers of lake users, more numerous and more powerful water-craft, boom boxes ashore and in boats, partying, thoughtless operators, etc.
  • Excessively high beaver and muskrat populations inflict substantial damage to shorelines, docks, retaining walls, trees, shrubs, electric wiring, anchor lines, etc.
  • Biting insects, aquatic weeds, and zebra mussels are ongoing nuisances, and deserve at least a mention in this category.
  • A High Level of PHOSPHATES is occurring in the lake causing multiple issues including an increasing number of aquatic weeds.
Potential Problems
  • High titers of E. coli bacteria could result from septic system breakdowns, poor designs, or unregulated or unauthorized installations.
  • If waterfowl lead poisoning is not already occurring, it could be a future problem.
  • Elevated population levels of double-breasted cormorants, herring gulls, and Canada geese could become a problem.
  • The loss of the Lyndhurst dam is highly unlikely. If this did occur, the results would be disastrous to lakeside owners. It would take years for the complex processes of government to replace the structure.
Suggested or possible actions
  • Support laws and policies which regulate development. Promote land set-asides or public ownerships where it is unlikely to result in lakeshore development. Encourage owners to work with land trusts. Offer information sessions where these options could be explored and considered.
  • Communicate actively with the Ontario Ministry of Natural Resources in relation to water level management of Lower Beverley Lake. Establish a lake-water level monitoring station which will be seen and read by cottage owners. Report unusual rainfall events to appropriate MNR water resource technicians. Try to get lakeside owners interested in expressing their views about optimum lake levels. Make some high level contacts within the Ministry, and bring complaints about lake level management to the highest authorities.
  • Ascertain prevailing laws and enforcement arrangements in relation to excessive noise. Make lake users aware of LBLA member’s concerns in relation to noise.
  • It is unlikely that excess beaver and muskrat populations can be controlled unless fur prices rebound (this is neither imminent nor probable). Individual lakeside owners must cope on an individual basis.
  • Try to increase LBLA dues-paying memberships. Circulate lists of current members so that new ones can be recruited. What about the numerous offspring of present members who will ultimately inherit lakeside property?
Actions recently taken
We now have annual deployment of Hazard Markers.
We are undertaking increased water testing to see if the source of the PHOSPHATES can be determined and then hopefully resolved.
9. References
  • Hesse, Allee and Schmidt. 1937. “Ecological Animal Geography”. John Wiley & Sons. NY.
  • Hughes, Janice M. 2001. The ROM Field Guide to Birds of Ontario. Royal Ontario Museum of Toronto
  • Legget, Robert 1955. “Rideau Waterway”. University of Toronto Press.
  • Toner, G.C. 1938. Biological Survey of Lower Beverley Lake, Leeds County, Ontario. Bull, Eastern Ontario Fish and Game Protective Association, Gananoque.
10. Acknowledgements
Valuable comments and input were provided by:
  • Dale McLenaghan, Water Resource Technician and Scott Smithers, Wildlife Biologist, both from the Ontario Ministry of Natural Resources.
  • Sean Watt, Water Management Specialist; Tom Beaubiah, Conservation Issues Specialist; and Bill Warwick, responsible for administration and management: all associated with the Cataraqui Region Conservation Authority.

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