LAKE OF BAYS SUBWATERSHED

Index Map

The subwatershed is 38,513 hectares in area and is in the eastern portion of The District Municipality of Muskoka. Lake of Bays itself has a surface area of approximately 75 km2.

Less than 5% of the subwatershed is developed with 24% of the land being Crown land. Portions of the villages of Baysville, Dwight and Dorset lie within the subwatershed and shoreline residential development comprises most of the land use. 1% of the subwatershed is protected through provincial parks, crown nature reserves, or local land trusts. There are 25 other lakes over 8 hectares in size in the subwatershed.

There is one dam in the Lake of Bays subwatershed located at Baysville but there is no power generation. There are two automatic water level gauges and one flow gauge on the system.

Grades Land: B Water: B Wetland: —

This report card describes the health of the land, water and wetlands of the Lake of Bays subwatershed and is part of the larger report The 2010 Muskoka Watershed Report Card that is posted on the MWC website www.muskokaheritage.org/watershed.

Partnering with Nature Land GradeB

Natural Cover Large Natural Areas The Lake of Bays subwatershed is dominated by the lake itself with several smaller lakes feeding into it. Mixed forest dominates the subwatershed with development focused in the waterfront areas. The development pattern has resulted in a fragmented landscape with reduced interior forest habitat which is an important landscape feature that supports local biodiversity. Natural areas are also important to help purify the air, maintain good water quality and provide a carbon sink.

75% of the subwatershed is privately owned and it is important to encourage a strong private land stewardship program to ensure that the long-term health of the subwatershed is maintained as development occurs. Private land stewardship activities such as participation in MFTIP, CLTIP, and donations to land trusts is encouraged to maintain the values enjoyed in this subwatershed.

Both healthy riparian areas and interior Managed & forests are important to support local Protected Areas Interior Forest wildlife and maintain good water quality.

Muskoka Lake of Bays Indicator Watershed Indicator Description % Grade % Grade Natural cover is defined as lakes, wetlands, forests, rock barrens Natural Cover 97 A 94 A and other natural systems. Large Natural Areas 79 B 79 B 200 - 499 ha 7 7 Areas of natural cover that are 200 ha or greater. 500 - 9,999 ha 70 52 >10,000 ha 2 20 Interior forest is defined as a forested area with a 100-metre Interior Forest 48 B 58 C forested buffer surrounding it. Managed & Protected Areas 36 B 48 A Protected areas are defined as lands within national or provincial parks, Crown conservation reserves, Crown land, and land held Parks & Protected Areas 1 17 by land trusts. Managed areas are defined as lands under the Managed Forest Tax Incentive Program or Conservation Land Crown Land 24 26 Tax Incentive Program, or have a conservation easement held by Private Stewardship 11 5 a reputable conservation organization. Riparian area is defined as the shoreline of a lake or river plus an Riparian Area 59 B 68 B area 20 metres inland from the shore. GradeB Water The Lake of Bays subwatershed receives water from the headwater lakes in Algonquin Park and the undeveloped Crown portion of . The lake itself supports a healthy cold water fishery.

Total phosphorus is an indication of the nutrient level of waterbody. A background or un- developed level of total phosphorus has been determined for each lake. Scientists indi- cate that a lake may become unhealthy with an increase in phosphorus greater than 50% In Muskoka there are no notable from that background level. This is considered the threshold for that lake. Two lakes are point sources of industrial Over Threshold in the Lake of Bays subwatershed for a total of 0.9% of the total water contamination in lakes and rivers. surface area in the subwatershed. Most industrial contamination is generally a result of air pollutants Shoreline vegetation protects waterbodies from nutrients and toxic chemicals that can traveling long distances and being contribute to water quality issues. It also protects the lake edge from erosion caused by deposited in local lakes. In inland waves and ice. The shoreline zone provides critical habitat for fish and other animals, lakes on the Canadian Shield, helping to maintain a natural balance in sensitive aquatic ecosystems. 12% of the shore- mercury in fish is the most significant lines in the Lake of Bays subwatershed have been altered. contaminant. Muskoka Lake of Bays Mercury levels in lakes does not Indicator Watershed Indicator Description pose a significant human health % Grade % Grade threat, however, wildlife like loons are more sensitive. Loons eat fish % Surface This is a measure of recreational water that are 4 to 10 centimeters in size. If Area Over 0.9 B 4.9 B quality as phosphorus is generally the fish in a particular lake do not reach Threshold limiting nutrient in algae production. the 0.033 ppm standard until the fish This is a measure of fish habitat. Many is over 10 centimeters, then loons % Natural fish species require overhanging 88 B 91 B will not be impacted. Otherwise, Shoreline vegetation, rock shoals, and aquatic there could be a possible vegetation found in undisturbed sites. neurological impact. All of the fish Mercury levels in lakes do not pose a species tested for mercury in the Mercury significant human health threat, Lake of Bays subwatershed meet the Levels in Fish N/A A N/A B however, wildlife like loons are less standard for mercury. Less Than 10 tolerant to mercury and may be cm in Size impacted in some cases.

Wetlands —No Grade

Wetland Values

 Control and storage of surface water and recharge groundwater; The Lake of Bays subwatershed  Maintain and improve water quality, aid has 3,350 hectares of wetlands, in flood control, and protect shorelines which covers 8.7% of the from erosion; subwatershed.  Trap sediments which would otherwise fill watercourses; A value of no net loss of wetlands  Support and initiate complex food from the 2010 level will be used chains; as the benchmark. In future report  Provide important habitat cards, wetland area will be measured as a deviation from  Support species at risk; current wetland area.  Provides fish populations;  Provide active and passive recreational opportunities, including canoeing, bird watching, hunting and fishing. A changing climate

The biggest unknown in watershed health is the impact of climate change. What will climate change mean in Muskoka?

Warmer summers will see increased evaporation of water from lake surfaces and increased transpiration of water by wetlands and forests, meaning less Get involved and be a watershed steward runoff, less water, lower lake levels, and longer periods of drought. Warmer When all is said and done, the fate of sustainable management of a watershed winters will see more winter thaws and lies in the hands of grass-roots residents as they go about their day-to-day winter rains potentially leading to more business. It is the citizens of the watershed who must generate the interest and flooding. If the snowpack is reduced enthusiasm to create, continue and expand local projects which lead to positive due to mid-winter thaws then less snow actions and results. pack remains for the spring run-off, which could result in an earlier onset of 1. Maintain large natural areas drought and lower water levels.  Practice sustainable forestry  Use existing roads and rights of way for access Warmer lakes will likely lead and utility corridors to:  Reduce cleared areas in the rural area

 less habitat for lake trout 2. Retain shorelines in a natural state  more algae blooms and possibly blue  Maintain a wide natural buffer of plants and -green algae blooms trees around shorelines of lakes, rivers and streams Warmer temperatures will  Obey speed signs in erosion sensitive low wake likely: areas  allow a greater range of insects and  Reduce grassed lawns in the waterfront area disease in our forests, such as the and minimize the use of fertilizer Mountain Pine Beetle  Pick up after pets  allow more invasive species, such as  Plant native species ticks that carry lyme disease  result in more smog days and result 3. Protect wetlands in human health impacts  Leave wetlands alone  eliminate winter recreation although  Keep recreational vehicles out of wetlands summer recreation may be enhanced  Learn about wetland values  extend the growing season 4. Reduce your carbon footprint More severe weather events  Plant native trees will likely:  Reduce your use of electricity

 damage large tracts of commercially  Improve energy efficiency of your home and important forests vehicle Reduce waste  overload municipal infrastructure   result in more damage to agricultural crops

Drier conditions will likely lead to more drought.

Rapid change in habitat conditions will likely reduce biodiversity.

The Muskoka Watershed Report Card is produced by the Muskoka Watershed Council. The mission of the Muskoka Watershed Council is to champion watershed health.

For the full background report, visit www.muskokaheritage.org/watershed.