Cataraqui Region Conservation Authority March 29, 2019 Brent Parsons, M.Sc., Senior Aquatic Scientist Hutchinson Environmental Sciences Ltd.
Assessment of Municipal Site Evaluation Guidelines for Waterfront Development in Eastern Ontario’s Lake Country Review and Analysis of Existing Approaches for Managing Shoreline Development on Inland Lakes District of Muskoka Lake System Health Program Lac La Biche Sensitive Habitat Index Mapping and Shoreline Management Guidelines 2
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Evaluation of lake characteristics ◦ Focused on phosphorus ◦ Help to determine effectiveness of old site evaluation guidelines (Michalski and Usher, 1992) ◦ Trends in Total Phosphorus of heavily developed lakes between 2002 and 2012 ◦ Lakes: MVCA – Kashawakamak, Mazinaw, Sharbot RVCA – Otty, Upper Rideau CRCA – Buck, Charleston, Indian, Loughborough ◦ Trends either sporadic (MVCA) or declining (RVCA, CRCA) 4
25.0 20.0 L) TP (ug/L) 15.0 10.0 Sharbot - Site 4 5.0 0.0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year 25.0 20.0 Charleston - Site 1 L) TP (ug/L) 15.0 Charleston - Site 2 Charleston - Site 3 10.0 Charleston - Site 4 5.0 Charleston - Site 5 0.0 Charleston - Site 6 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Charleston - Site 7 Year 40 30 L) TP (ug/L) 20 Upper Rideau - Site 1 10 0 Upper Rideau - Site 2 1996 1997 1988 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year 5
Assessment criteria ◦ Soils Soil Character Soil Depth Chemical Analyses Site Sensitivity Deep Soils Shallow Soils Loam Sandy Loam Silty Clay Coarse sand and gravel ◦ Slope 0 - 5% 5 - 13% 13 - 20% >25% Site Sensitivity ◦ Vegetation Dense Understory Dense Canopy Sparse Canopy Sparse Understory Site Sensitivity 6
Mitigation Measures ◦ Erosion and Sediment Control Minimal Buffer (30m) Larger Buffer ◦ Shoreline buffer Site Sensitivity Site Sensitivity Moderately Coarse Soils Coarse or Fine Soils Deep Soils Shallow Soils Flat Terrain Steep Terrain Dense Vegetation Sparse Vegetation or Transformation to Ornamental Lawn Conventional Septic System and Leaching Bed Tertiary Treatment ◦ Sewage systems Site Sensitivity Site Sensitivity Moderately coarse soils Coarse or fine soils Deep Soils Shallow Soils/Bedrock Flat Terrain Steep Terrain Dense Vegetation Sparse Vegetation 7
Other Considerations: ◦ Natural heritage features ◦ Lakeshore Capacity Assessment ◦ Recreational Carrying Capacity ◦ Lake Trout habitat 8
Evaluation Criteria Checklist Site Description a. ✓ - Topographic features ✓ - Natural hazards such as areas prone to flood or erosion ✓ - Watercourses, ponds, wetlands ✓ - Lot size, frontage, depth, area, shape ✓ - Permanent and intermittent streams ✓ -expected path of surface runoff ✓ - Aquatic vegetation & ecological description - Terrestrial vegetation community See Table 5 for scoring b. Soil Characteristics ✓ - Document and map soil conditions ✓ - Characterize soils used for leaching beds ✓ - Characterize native soils in mantle ✓ - Location of leaching bed ✓ - Pathway of subsurface flow relative to lake - Manual auguring to determine soil depth See Table 5 for scoring ✓ - Sources of suitable soil for raised fields - Soil Character - type, texture, colour See Table 5 for scoring c. Slopes ✓ - Site contours - Slope areas (0-10, 10-15, 15-20, 20-25, >25%) See Table 5 for scoring ✓ - Depressions and gullies that channel water 9
d. Vegetation cover - Map location and character of shoreline & See Table 5 for scoring upland vegetation ✓ - Photographic documentation ✓ -property shoreline (from lake) ✓ -tile field along direction of flow ✓ -building envelope shortest dist to lake e. Description of how development will occur ✓ - Building location ✓ - Septic system location ✓ - Parking and other hard surfaces ✓ - Proximity to significant features ✓ - geological ✓ - man-made ✓ - wetlands, streams, other water f. Standard mitigation measures to eliminate impacts of nutrient and sediment loading ✓ - Detailed construction mitigation plan ✓ - Stormwater management plan including control of runoff and other BMPs Incorporation of “b” horizon soils ✓ - ✓ - Minimum 30 m shoreline setbacks and buffer areas ✓ - Delineate building envelopes ✓ - showing setbacks from shore ✓ - showing yard setbacks ✓ - showing septics location ✓ - Show protection for natural vegetation ✓ - slopes and soil mantle for areas outside of building envelope 10
Biophysical Site Scoring Site Criteria Score Characteristic Soil Depth Depth (cm) >150 0 100-150 2 75-100 4 50-75 6 25-50 8 <25 10 Soil Texture Type Percolation Rate Phosphorus Retention Capability Coarse sand and Excessively rapid Low 10 gravel Total Score Recommended Depth of Shoreline Buffer (m) Silty clay and clay Low to impermeable High 7 36-40 90 Well-graded sands Permeable to Low to medium 5 moderate 31-35 80 Silty sand, clayey Moderate to low Medium to high 3 26-30 70 sand, silt and fine sand 21-25 60 Sandy loam Moderate to low Medium to high 3 16-20 50 Loam Permeable to Medium to high 0 moderate 11-15 40 Soil Analysis If native soil between tile field and lake is > 1m deep, <1% CaCO 3 and -10 ≤ 10 30 >1% Iron/Aluminum Slope Slope Class 0%-13% 0 13%-20% 8 20%-25% 10 >25% 12 Vegetation Vegetation Cover Type Undisturbed woodlands, old fields, and meadows 0 Disturbed woodlands, old fields, and meadows 3 Close-seeded legumes (clover, alfalfa) and rotation meadows 5 Row crops 7 Fallow fields and base bedrock outcrops 10 11
Conclusions ◦ Phosphorus concentrations in lakes in the area do not appear to be increasing ◦ Literature reviews can be blurry but it’s clear that site specific features should be taken into account ◦ Old approach has stood the test of time ◦ Evaluation criteria and biophysical site scoring are effective tools for planners, lake managers, proponents, etc. 12
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Review of 14 jurisdictions across North America Shoreline management by: 1. Capacity development limits based on thresholds and densities 2. Best Management Practices BMPs and minimum development standards to mitigate impacts ◦ Classification – used to inform capacity and determine BMPs/development standards 14
Capacity Tools ◦ Lakeshore Capacity Assessment ◦ Lake Trout Policy ◦ Recreational Carrying Capacity Mitigation Tools ◦ Stormwater Management ◦ Shoreline Buffer ◦ Septic System Design and Maintenance ◦ Minimum Development Standards ◦ Soils Assessment Classification Tools ◦ Water Quality ◦ Lake Features (e.g. depth, surface area) ◦ Responsiveness to Phosphorus ◦ Current Development 15
Building Setback Septic Setback Jurisdiction Lot Size (ha) Lot Frontage (m) (m) (m) Elliot Lake 20 - 0.4 45 Kenora - Black 20 - 0.8 61 (122 for Sturgeon Lake restricted development area) Muskoka 20 30 - 60 (increased frontages to a maximum of 120 m may be required adjacent to narrow waterways) Muskoka Lakes 20 30 - 60 (may be increased due to natural constraints) Seguin 20 1 - 1 (1.2 for island 90 (120 for island lots) lots) Lake Simcoe 15 - - - Protection Plan (Town of Innisfil) 30 – 90 2 CRCA, MVCA, RVCA - - 60 (Rideau Lakes) Cariboo 7.6 35 - 46 23 - 76 3 Maine 30 0.19 61 23 – 38 4 New Hampshire - - 46 23 – 46 5 0.19 – 0.74 5 30 – 61 5 Minnesota - Wisconsin 23 - 0.19 30 1 may be increased to address water quality, wetland, fish habitat or other similar issues 2 with greater setback dependant on biophysical site criteria 3 depending on shoreland zone classification 4 depending on percolation rate of soil 5 depending on lake classification - indicates that standard was not provided in the documentation reviewed, but for Ontario jurisdictions the OBC requirement is 15 m. 16
Conclusions ◦ Lots of tools ◦ Challenging to monitor success of tools ◦ BMPs and high minimum development standards can be protective of a variety of features and functions but enforcement is key ◦ Lake classification/screening recommended to tailor capacity and mitigation tools to address specific features of lakes and watersheds 17
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Program initiated in 1980s with regular review and revisions. Has included 3 main components: Lakeshore Capacity Modelling of over 500 lakes 1. Water quality monitoring of 190 lakes to track 2. water quality, inform modelling and residents Official Plan policies that use the model and 3. monitoring results to guide the amount and nature of development on individual lakes 19
Notable revisions of most recent approach: ◦ Eliminating classification of lakes based on modelled estimates of phosphorus ◦ Increased focused on water quality monitoring results ◦ Recognition of BMPs and development standards that can mitigate impacts 20
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