ENVIRONMENTAL IMPACT STATEMENT & TREE CONSERVATION REPORT
LOTS 18 & 19, CONCESSION I
FORMER CITY of KANATA, CITY of OTTAWA
A report prepared for:
1384341 Ontario Ltd.
by MUNCASTER ENVIRONMENTAL PLANNING INC.
Revised March, 2013 MUNCASTER ENVIRONMETAL PLANNING INC.
TABLE OF CONTENTS
1.0 INTRODUCTION...... 1 1.1 Scoping the Environmental Impact Statement ...... 3
2.0 METHODOLOGY ...... 3
3.0 EXISTING CONDITIONS ...... 4 3.1 Geologic and Hydrologic Conditions...... 4 3.2 Terrestrial Features ...... 6 3.3 Significant Features...... 11
4.0 DEVELOPMENT PROPOSAL ...... 14 4.1 Proposed Land Use ...... 14 4.2 Stormwater Management ...... 16
5.0 POTENTIAL IMPACTS and MITIGATION MEASURES ...... 16 5.1 Terrestrial Habitat ...... 16 5.2 Aquatic Habitat ...... 19 5.3 Stormwater Mitigation ...... 21 5.4 Erosion and Sediment Controls ...... 22
6.0 CUMULATIVE EFFECTS and SUMMARY ...... 23
7.0 REFERENCES ...... 24
FIGURE
Map 1: Current Vegetation ...... 2 Map 2: Proposed Retained Vegetation ...... 15
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page i MUNCASTER ENVIRONMETAL PLANNING INC.
1.0 INTRODUCTION
The 60 hectare site is within the north portion of Lot 18 and the south portion of Lot 19, Concession I, in the former City of Kanata, now in the City of Ottawa (Map 1). The site is located approximately 1.5 kilometres north of March Road, with Marchurst Road along the east boundary. The municipal address is 1913 Marchurst Road.
The concept plan developed for the site is shown on Map 2. The proposal is for 53 rural residential lots with a minimum lot size of 0.8 hectares, up to 1.8 hectares. All but seven of the proposed lots are between 0.8 and 0.95 hectares. The site will be serviced with individual wells and septic systems, with stormwater management described in the Preliminary Stormwater Management Report by Stantec (2012). The study area is currently mostly agricultural fields, with deciduous forests in the northwest and southwest parcels of the property. The surrounding land use includes agriculture to the north and east, recent rural residential to the south and the 4,752 hectare Carp Hills Natural Area to the west. The forest in the northwest corner of the site is included in the Carp Hills Natural Area, which was considered to have a high overall significance in the evaluation summary performed as part of the Natural Environment System Strategy by the former Region of Ottawa-Carleton (Brunton, 1997). More information on the Natural Area is provided in Section 3.3.
The closest portion of the Provincially significant Carp Hills Wetland Complex is approximately 250 metres to the west of the west site boundary. As the surface flow on the site is to the east, away from the significant wetland habitat, and the distance between the site and the closest wetland parcel is considerable, it is not anticipated that the significant wetland habitat will be directly or indirectly impacted by the proposed development.
The south boundary of the Carp Hills regionally-significant candidate Area of Natural and Scientific Interest (ANSI), as depicted in Brunton (1995) and Robinson (2004) is located to the west of the site, within Lot 19 of Concession I of the former Township of West Carleton (Huntley Geographic Township). The Provincially-significant Carp Barrens ANSI is located further to the north, approximately 900 metres from the northwest corner of the site, within the larger Carp Hills ANSI boundary.
The designation for the site is General Rural Area in the City of Ottawa’s 2003 Official Plan (City of Ottawa, 2003). The site and lands to the south are zoned Rural Residential (RR3), with lands to the north and east zoned General Rural and lands to the west zoned Environmental Protection, and along an unopened road allowance immediately to the west of the site, Parks and Open Space. No constraints are shown in the vicinity of the site on Schedule K of the Official Plan. The on-site and adjacent forests to the west are shown as Significant Woodlands on Annex 14: Natural Heritage Systems of Official Plan Amendment 76.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 1
MUNCASTER ENVIRONMENTAL PLANNING INC.
As land to the west of the site is designated Natural Environment Area in the 2003 Official Plan and Significant Woodlands are identified, Section 4.7.8 of the Official Plan requires an Environmental Impact Statement (EIS) as part of the development application.
1.1 Scoping the Environmental Impact Statement
This EIS was prepared in accordance with Section 4.7.8 of the City of Ottawa Official Plan (2003) following the EIS Guidelines and the Guidelines for City of Ottawa Tree Conservation Report, found at http://ottawa.ca/en/city_hall/planningprojectsreports/planning/dev_review_process/guide/environ mental_impact/ and http://ottawa.ca/en/env_water/tlg/trees/preservation/guidelines/index.html,with guidance from the Natural Heritage Reference Manual (OMNR, 2010). Note that the current version of the EIS Guidelines, 2nd Edition April 2012, was utilized for this report with the City web link soon to be updated with this new version. This report includes the components of an Environmental Impact Statement as identified in Section 4.7.8.2 a) through h) of the City of Ottawa Official Plan (City of Ottawa, 2003).
The Natural Heritage Reference Manual (OMNR, 2010) was reviewed to identify potential items that the EIS should address. The following items were identified for particular attention, recognizing that many of these issues are interrelated:
what are the anticipated direct and indirect potential impacts on the features and functions of the natural area that are anticipated from a change in land use on the site? how are the features and functions of the natural area influenced or supported by the site, including linkages and unique habitats?; will increases in impermeable surfaces and operation of residential units result in impacts on infiltration and groundwater?; what are the potential impacts associated with the construction and operation of stormwater management?; what are the on-site natural environment features and functions?; and, can a concept plan incorporate retention of the more important natural features and functions of the site?
2.0 METHODOLOGY
Environmental information was collected and summarized through:
information on the Carp Hills Natural Area from the Natural Environment System Strategy files at the City of Ottawa; information on the regionally-significant candidate Area of Natural and Scientific Interest from Ministry of Natural Resources files in the Kemptville District office;
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 3 MUNCASTER ENVIRONMENTAL PLANNING INC.
a review of the Ministry of Natural Resources, City of Ottawa, Natural Heritage Information Centre and Ontario Breeding Bird Atlas databases to identify potential species of interest in the vicinity of the site; field surveys of the site and adjacent lands completed on November 18, 2004, July 18th, 2005 and September 9th, 2011. Observations were made on vegetation communities and associated wildlife habitat within and adjacent to the site; and, a review of the other studies associated with the application such as the stormwater servicing brief.
Colour aerial photography (2002 - 2012) was used to assess the natural environment features in the general vicinity of the site. Ecological units were defined based on species present, the wetness index of the species, dominant species, locations of standing water and other drainage observations, health, age, topography and soil conditions. As part of the surveys, the potential wildlife habitat attributes of the site were examined.
Other aspects of the surveys included photographs of site representative features and observations on the level of disturbance from human activities and non-native flora and fauna.
The field survey and this report were completed by Bernie Muncaster, who has a Master’s of Science in Biology and over twenty-four years of experience in completing natural environment assessments. The purpose of the Tree Conservation Report component is to establish which vegetation should be retained and protected on the site. The owner of the site is 1384341 Ontario Ltd. c\o Thomas Cavanagh Construction Limited (613-257-2918). It is proposed to remove the woody vegetation not to be retained in 2013 before the breeding bird season.
3.0 EXISTING CONDITIONS
3.1 Geologic and Hydrologic Conditions
The soils in the southwest and northwest portions of the site are limited, with exposed Precambrian bedrock common in many areas. The balance of the site is dominated by poorly drained silty clay loams closer to Marchurst Road and well drained sandy loams in the central- west portion of the site (Schut and Wilson, 1987). The topography of the central and east portions of site is generally flat with pockets of bedrock outcroppings, with the extent of outcroppings much greater in the southwest and northwest portions of the site.
The site is within the Constance Creek subwatershed, which drains to the Ottawa River. Drainage is to the east in an east-west orientation through the site, and is collected by a roadside ditch along Marchurst Road. The on-site channel likely provides intermittent direct fish habitat. In the autumn the water depth was up to 15cm with a wetted width of between 0.75 and 1.25 metres. The dominant substrate was muck. The channel was dry in the summer with vegetation throughout including reed canary grass, sedges, soft-stemmed bulrush, wool grass, timothy, joe- pye-weed, boneset, red clover and blue vervain (Photos 1 and 2).. Woody vegetation along the drainage feature outside of the southwest forest was limited to speckled alder and pussy willow
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 4 MUNCASTER ENVIRONMENTAL PLANNING INC. shrubs and a couple of deciduous (red ash and bur oak) trees. No pool habitat that could potentially be used as a refuge by fish during the drier periods was present. The on-site channel flows into a roadside ditch on the west side of Marchurst Road. There was no flow observed in the roadside ditch in the summer although small areas of disconnected standing water were noted. The depth of the standing water was less than 5cm. The roadside ditch is also grown through with reed canary grass and broad-leaved cattail.
The more minor drainage features in the central and north portions of the site do not represent potential fish habitat due to the dominance of non-aquatic vegetation through the swales in many areas and lack of a defined stream channel. Many of the smaller on-site drainage features appeared to convey flow from tile drainage outlets.
Photo 1 – Summer vegetation through channel in east portion of the site. View looking east to Marchurst Road
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 5 MUNCASTER ENVIRONMENTAL PLANNING INC.
Photo 2 – Summer vegetation through channel in south-central portion of the site. View looking northeast
3.2 Terrestrial Features
The northwest corner of the site is forested and is part of the southeast corner of the Carp Hills Natural Area, designated Area 538 in the former Region of Ottawa-Carleton’s Natural Environment System Strategy (Brunton, 1997). The only other forested portion of the site is in the southwest corner. The balance of the site is agricultural fields, with scattered pockets of cultural woodland and thicket vegetation.
Dry-Fresh Poplar Deciduous Forests
The forests are dry-fresh poplar deciduous forests dominated by trembling aspen, large-tooth aspen, balsam poplar and white birch, with poplar particularly dominant in the east portions of the forests. White elm, white ash, bur oak, red ash, black cherry, sugar maple, ironwood, red maple, Manitoba maple, red oak and basswood are also common. Regeneration of white elm, trembling aspen and red oak was noted in several areas although the overall extent of regenerating stems is low. The only conifer representation on the site is a couple of small white pines (up to 15cm diameter at breast height (dbh)) in the southwest forest and a couple of small white spruce in the northwest forest. The non-native and invasive common buckthorn is dominant in many areas of the understory of the southwest forest with chokecherry and glossy buckthorn also present. The extent of buckthorn is much less in the west portion of the
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 6 MUNCASTER ENVIRONMENTAL PLANNING INC. northwest forest, but buckthorn is abundant in the east portion (Photos 3 and 4). Poison ivy, eastern bracken, yellow avens, Canada goldenrods, tall goldenrod, large-leaved aster, heart- leaved aster, timothy, thicket creeper, butter-and-eggs and rough-fruited cinquefoil are representative of the ground flora.
Logging has disturbed both forests. Due to the logging, the majority of trees are less than 20cm dbh (Photo 3). White ash and bur oaks up to 55cm dbh along the south edge of the northwest forest and a 60cm dbh white elm at the northeast edge of the southwest forest were the largest trees in the forests. The canopy within the forests is open in many areas, especially in the areas of exposed bedrock. In these open areas common juniper is dominant, with red-osier dogwood, common buckthorn, red raspberry, blackberry and speckled alder well represented in some of the open areas.
The southwest forest has a wide (between seven and fifteen metres) access road through it. The road curves to the north at the southwest corner of the property and there is a cleared area of approximately 15 metres in width between the southwest forest and the Carp Hills Natural Area to the west (Photo 6). The forests representing the Natural Area to the west of the site are also generally young, with the vast majority of trees less than 25cm dbh. The species composition is generally similar, all upland deciduous habitat with poplar, white elm and maple the dominant tree species. The canopy cover is generally greater in the forests to the west of the site than the on-site northwest and southwest forests.
The on-site forests are approximately 240 metres in width at their widest point and thus have a minimal amount of forest interior habitat. Bedrock outcrops are more common in the northwest forest than the southwest forest (Photo 5). A small shallow pond in the southwest corner of the northwest forest is a man-made feature with extensive cattle access and erosion. It has no natural heritage value.
The vegetation communities for Natural Area 538 identify the northwest forest as upland deciduous poplar forest with maple representation. This vegetation community/landform representation was not considered an example of the ten largest examples of common representations within the former Region, or an example of rare representation (Brunton, 1997).
Cultural Woodlots and Thickets
Small treed areas are in the vicinity of outcrops scattered among the agricultural fields. Sugar maple, bur oak and basswood are common, with white ash, red ash, white elm, Manitoba maple, white birch and trembling aspen also present. The largest trees appearing to be in good condition are bur oaks up to 60cm dbh. A large sugar maple (80cm dbh) is in senescence, with many broken limbs.
Where the tree cover is less than 25 percent this habitat is identified as cultural thicket on Map 1. Shrubs species include common buckthorn, staghorn sumac, nannyberry, red raspberry, hawthorn, Bebb’s willow, pussy willow, and apple with Canada goldenrod, heart-leaved aster,
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 7 MUNCASTER ENVIRONMENTAL PLANNING INC. calico aster, yellow avens, poison ivy and butter-and-eggs common ground flora.
Deciduous Hedgerows
Intermittent deciduous hedgerows along the north and south site peripheries include red ash, bur oak and sugar maple with the largest trees bur oaks and sugar maples up to 80cm and 65cm dbh, respectively.
Cultural Meadows/Agricultural Fields
The agricultural fields were tilled in 2011 (Photos 7 and 8).
Photo 3 – West portion of the northwest forest has less disturbance in the understorey
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 8 MUNCASTER ENVIRONMENTAL PLANNING INC.
Photo 4 – The east portion of the northwest forest has much more disturbance in the understorey
Photo 5 – One of the larger bedrock outcropping in the central-west portion of the northwest forest
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 9 MUNCASTER ENVIRONMENTAL PLANNING INC.
Photo 6 – Break in the canopy cover between the southwest forest on the right and the deciduous forests to the west of the site. View looking north
Photo 7 – Agricultural field in the east portion of the site. View looking east from the northwest corner of the field
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 10 MUNCASTER ENVIRONMENTAL PLANNING INC.
Photo 8 – Agricultural field in the north-central portion of the site. View looking north from the south portion of the field
Wildlife
Wildlife observations included American crow, turkey vulture, American kestrel, blue jay, black- capped chickadee, American robin, song sparrow, chipping sparrow, American woodchuck, American goldfinch, cedar waxwing, immature rose-breasted grosbeak, ruffed grouse, hairy woodpecker, downy woodpecker, pileated woodpecker, northern leopard frog, red squirrel, eastern chipmunk, raccoon, white-tailed deer and eastern cottontail. A few snags in the northwest forest had extensive woodpecker activity. Old beaver cutting were noted in the west portion of the northwest forest.
3.3 Significant Features
The potential sensitivities of the natural heritage features and functions, including wildlife utilization and vegetation communities, are assessed through consideration of the condition and other components of the features including age, habitat maturity, rarity, diversity, regeneration and other unique and significant features. The condition of the features is influenced by factors such as past land use, representation of non-native components, existing disturbances and adjacent land uses.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 11 MUNCASTER ENVIRONMENTAL PLANNING INC.
Carp Hills NESS 538
The large (4,752 hectare) Carp Hills Natural Area was considered to have a high overall significance in the evaluation summary performed as part of the Natural Environment System Strategy (Brunton, 1997). The overall high significant rating was due to an evaluation of several criteria. The Natural Area was considered to have high significance for seasonal wildlife concentrations, the condition of the natural area, hydrological features, rare vegetation community/landform types, endangered, threatened and rare species, and vegetation community/landform species diversity, and low significance for common vegetation community/landform type representation. The Carp Ridge represents an inter-regional linkage.
The Natural Area is described by Brunton (1997) as a relatively homogeneous landscape of dry, upland deciduous and mixed forests on thinly-mantled Precambrian outcrops along the Carp Ridge. Numerous small, irregularly shaped shallow wetland areas are scattered across the Natural Area, supporting open water, marsh, thicket swamp and swamp forest habitat (Brunton, 1997). As indicated above the closest mapped wetland parcel is approximately 250 metres to the west of the west edge of the site.
The degree of human disturbance for the Natural Area was considered low by Brunton (1997) with low site fragmentation and low impact of alien species.
The on-site vegetation communities are not representative of the rare vegetation community and landform type combinations reported by Brunton (1997) in the Natural Area summary. Rare species reported for the Natural Area are discussed below, as are potential significant wildlife habitat features.
Species at Risk and other Species of Special Interest
No butternuts or other Species at Risk were observed on or adjacent to the site. The Ontario Ministry of Natural Resources’ biodiversity explorer website was reviewed (http://www.biodiversityexplorer.mnr.gov.on.ca/nhicWEB/main.jsp). This site allows for a search of Threatened and Endangered species covered by the 2008 Endangered Species Act, as well as other species of interest. Searches were conducted on the 10 km square including the site and the general area (18VR22). Blanding’s turtle and least bittern are threatened Species at Risk, along with the endangered American ginseng identified for the overall 10 km square, with two provincially rare species, ram's-head lady's-slipper and prairie dropseed, and one species of special concern, milksnake, reported. The breeding birds listed in the Ontario Breeding Bird Atlas for the 10 km square 18VR22 identified whip-poor-will, barn swallow, eastern meadowlark and bobolink as threatened Species at Risk, as well as golden-winged warbler, a species of special concern, in the overall 10 km square including the site.
In addition the potential Species at Risk in the overall City of Ottawa were reviewed, with an emphasis on the endangered and threatened species historically reported in the overall City, including butternut, American ginseng, eastern prairie fringed-orchid, flooded jellyskin, wood
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 12 MUNCASTER ENVIRONMENTAL PLANNING INC. turtle, spiny softshell, Blanding’s turtle, musk turtle, Henslow’s sparrow, loggerhead shrike, bobolink, barn swallow, eastern meadowlark, cerulean warbler, whip-poor-will, bald eagle, golden eagle, least bittern, peregrine falcon, eastern cougar, common gray fox, lake sturgeon, and American eel.
The habitat requirements of the species identified above were reviewed. Bobolink, barn swallow and eastern meadowlark utilize grasslands however the agricultural fields have been tilled and tilled fields do not represent potential bobolink or eastern meadowlark habitat. There are no structures on the site that may be utilized by barn swallow. Milksnake is relatively common in portions of eastern Ontario but is not often seen. It is found in open woodlands, clearings and around farmhouses where it hunts its major prey item, mice. The ram's-head lady's-slipper orchid is found in mature coniferous forests or coniferous fens and swamps. No suitable habitat is on or within 120 metres of the site. Due to the lack of open water and/or large marsh areas no suitable wetland habitat is present for Blanding’s turtle or least bittern on the site. Golden-winged warbler breeds in scrubby habitats and is known from the South March Highlands area to the southwest of the area, as is American ginseng which requires rich, moist, undisturbed and relatively mature sugar maple-dominated deciduous woods in areas of circumneutral soil such as over limestone or marble bedrock. Whip-poor-will requires large wooded areas with open patches, and/or open woodlands or alvar. The wooded areas on the site are considered too small and narrow to provide potential habitat.
The regionally rare fauna reported for the Carp Hills Natural Area by Brunton (1997) were lynx, American black bear, barred owl and Blandings turtle. With the possible exception of the American black bear, it is unlikely that any of these species breed or spend extended periods of time in the immediate vicinity of the site. Lynx are found only in dense climax boreal forests (Banfield, 1974). The barred owl prefers dense conifer and mixed conifer/deciduous forest, wooded swamps and river valleys (Ehrlich et al., 1988) and is unlikely to nest on the site in a relatively low-density forest at the periphery of the natural area. No stick raptor nests were observed during the field surveys. The flora reported by Brunton (1997) that is still considered regionally rare is generally associated with wetland and aquatic habitat or forests less disturbed than the on-site forests.
In summary no significant habitat of Species at Risk is considered present on the site.
Fish Habitat
The on-site channel provides intermittent fish habitat. This habitat is to be retained and protected by retaining the channel in its existing condition or realigning the channel, with appropriate setbacks to structures provided, as discussed in Section 5.2.
Significant Wildlife Habitat
No flora or fauna or ecological conditions were identified in the background review or field observations that would trigger a Significant Wildlife Habitat designation on the site. The study
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 13 MUNCASTER ENVIRONMENTAL PLANNING INC. area is located at the east edge of the Carp Hills Natural Area. Corridor functions to the west are likely extensive towards the core of the Natural Area. Some corridor function also likely occurs among the agricultural lands to north, east and south, although the function is limited by the recent rural residential development adjacent to the south edge of the site.
The specific features such as amphibian breeding areas, colonial bird nesting sites including a great blue heron colony, and winter feeding and roost areas for raptors identified by Brunton (1997) for the Carp Hills Natural Area were not observed on or adjacent to the site.
Significant Woodlands
The on-site forests have been logged and the remaining assemblage is not old enough to meet the City of Ottawa’s criteria of 80 years old for Significant Woodlands in the rural portion of the City. The on-site forests do support a limited amount of forest interior habitat as there are portions of the northwest forest up to 240 metres in width and the southwest forest contains a watercourse. Thus if older stands of trees are present in portions of the forest off-site, which is likely within the Carp Hills to the west of the site, the entire contiguous forest could be considered a Significant Woodlands. However, as assessed below the construction and operation of the rural family residences will not have a significant impact on the adjacent forests to the west. Any features and functions for which the forest may be considered significant woodlands will not be impacted. If the overall Carp Hills contiguous forest is a Significant Woodlands, it will remain a Significant Woodlands following construction and operation of the rural residences.
4.0 DEVELOPMENT PROPOSAL
4.1 Proposed Land Use
The proposed development is for 53 rural residential lots with a minimum lot size of 0.8 hectares. The site will be serviced with individual wells and septic systems.
Prior to development of the concept plan, mitigation measures for natural environment protection were provided. These measures are outlined in the next section and include deeper lots along the west edge of the to provide a buffer for the Natural Area to the west and identification of belts of trees proposed for retention, not only along the site peripheries but on the rear and sides of inner lots. The road network and lot layout has been designed to avoid crossings of the on-site channel supporting intermittent fish habitat other than one road crossing west of Marchurst Road. As shown on Map 2 below another east-west drainage feature to be enlarged/created will run at the rear of lots and will have two road crossings.
Construction is anticipated to begin in the spring of 2013.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 14
MUNCASTER ENVIRONMENTAL PLANNING INC.
4.2 Stormwater Management
Surface runoff from the site currently drains to existing channels which outlet to the roadside ditch on the west side of Marchurst Road. As shown on Map 2, the on-site channel in the south portion of the site will be relocated to the south to run near the rear of the lots and outside of the building envelopes for each lot. New channels will be created or enhanced to provide the onsite drainage leading to either the realigned east-west channel or roadside ditching. The site will continue to drain to the roadside ditch along the west side of Marchurst Road and the existing channel will remain in its current location for the first 250 metres west of Marchurst Road.
The preliminary stormwater management report identifies the best management practices to be implemented for on-site water quality and quantity control of stormwater runoff, as detailed in Section 5.3. These stormwater mitigation measures will ensure that pre and post development flow rates and quality remain comparable and that stormwater runoff will be addressed during the construction and operation phases of the development.
5.0 POTENTIAL IMPACTS and MITIGATION MEASURES
The potential impacts of the proposed development considered critical to the local natural system were scoped from features identified in the background information for the Carp Hills Natural Area and the regionally significant candidate Area of Natural and Scientific Interest to the west of the site and the field visits to the site and adjacent lands.
Natural heritage features and functions on the site are generally found in the southwest and northwest forests, with limited features associated with the intermittent drainage and the scattered woody vegetation in other portions of the site.
5.1 Terrestrial Habitat
Indirect impacts could occur on the Carp Hills Natural Area and regionally significant candidate Area of Natural and Scientific Interest to the west of the site as a result of the construction and operation of the residential development. These indirect impacts could include:
greater human, pet and other urban wildlife intrusions into the adjacent natural areas. Indirect impacts may also occur due to increases in noise and light pollution; increased sediment loadings and other contamination of surface water runoff during construction from machinery maintenance and operation, leading to erosion and other impacts on the natural area; and, a degradation in water quality through increased levels of fertilizers and pesticides in surface water runoff.
As the lots backing onto the west edge of the site are a minimum of 115 metres in depth the potential for these indirect impacts on the adjacent lands to the west can easily be greatly reduced by providing a minimum ‘no-touch’ buffer setback along the west edge of the site. This setback
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 16 MUNCASTER ENVIRONMENTAL PLANNING INC. is recommended to be thirty metres, with the development footprint of Lots 19-25 to be outside of this setback area. This setback is to be allowed to be naturalized where there is an existing access lane or agricultural lands.
Any grading or other site alterations done in the west portion of the site will be undertaken to ensure sedimentation can be controlled and easily directed away from the lands to the west. Both the new and relocated east-west channels will direct surface water to the east, as the current conditions are. This will ensure that there will be no potential for contamination of surface water entering the lands to the west.
The new landowners adjacent to the west portion of the site and in the northwest forest should be supplied with a conservation handbook highlighting the adjacent natural environment features and the importance of an environmental-friendly lifestyle. Issues that can be addressed in the handbook include use of pesticides, herbicides and fertilizers, rock gardens and other features to maximize design with nature concepts including surface water treatment and infiltration, control of pets, importance of limiting disturbances along the shoreline, and the impacts of non-native vegetation and improper disposal of yard waste.
The deciduous forests and scattered trees on the balance of the site do provide localized wildlife habitat and a natural amenity. As indicated in Section 3.2, the corridor function of the site is limited by the location of the forest at the very edge of the natural area. However to maximize the corridor functions, it is recommended that fencing and other potential impediments to wildlife movement be minimized as much as possible. As the canopy of the deciduous forests is open in many areas and there is very minimal on-site forest interior condition, there are no significant potential impacts associated with loss of forest interior habitat and creation of new forest edges that could result in sunscald or wind throw impacts will be minimal.
As the lot size is a minimum of 0.8 hectares extensive portions of the existing forests can be retained in their current condition as shown on Map 2. The deciduous forest habitat in the southwest and northwest forests and the scattered trees on the balance of the site represent opportunities for tree retention. This will assist in retaining the existing tree cover and wildlife habitat, including food, cover, and wildlife and plant corridor functions. More extensive natural areas are available for utilization by wildlife to the west of the site in the core of the Carp Hills Natural Area. It is intended that development will proceed in phases proceeding from Marchurst Road westerly to the rear of the site. This will ensure that a continuous means of egress will be maintained to allow the passage of wildlife from this site into the Carp Hills Natural Area and construction phasing will be provided that will not cut off wildlife from the adjacent Carp Hills Natural Area.
The 0.8 hectare lots will permit significant retention of trees, both in the forests and the scattered trees in the central portion of the site and at the edges. Although blasting is not likely to be required, fill will be needed for some of the septic beds. However there is ample opportunity on each lot in the forests for tree retention, as shown on Map 2. Individual trees and belts of trees that may be considered for retention on each lot will be identified prior to any construction on the
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 17 MUNCASTER ENVIRONMENTAL PLANNING INC. site and protected with fencing as described below. Some examples of individual trees within the areas proposed for retention include bur oak, trembling aspen and white ash in the southwest and north forests up to 50cm dbh, along with sugar maples in the forest up to 36cm dbh and smaller basswood and ironwood trees. Mature bur oaks up to 60cm dbh, along with sugar maple and red ash trees in the range of 35cm dbh are proposed for retention in the scattered areas of cultural woodland in the central portion of the site. The largest tree observed on the site, an 80cm dbh bur oak will be retained along the existing channel west of Marchurst Road. Smaller red ash are also along the portion of the existing channel to be retained. A mature, 65cm dbh, sugar maple, will also be retained in the intermittent hedgerow along the north portion of the site, west of Marchurst Road.
To maximum tree and shrub retention, the portions of each lot with less woody vegetation should be maximized within the building footprint. This includes the south portions of Lots 41, 43 and 49 and the north portion of Lot 40.
Trees and shrubs to be retained are to be protected with sturdy orange construction fencing at least 1.3 metres in height installed from the tree trunk a minimum distance of ten times the retained tree diameter. Signs, notices or posters are not to be attached to any tree. No grading, heavy machinery traffic, stockpiling of material, machinery maintenance and refueling or other activities that may cause soil compaction to occur within five metres of the critical root zone of the trees to be retained and protected. The root system, trunk or branches of the trees to be retained are to be protected and not damaged. If any roots of trees to be retained are exposed during site alterations, the roots shall be immediately reburied with soil or covered with filter cloth, burlap or woodchips and kept moist until the roots can be buried permanently. A covering of plastic should be used to retain moisture during an extended period when watering may not be possible. Any roots that must be cut are to be cut cleanly to facilitate healing and as far from the tree as possible. Exhaust fumes from all equipment during construction will not be directed towards the canopy of the retained trees to the south.
All of the supports and bracing for the protective fencing should be placed outside of the protected area and should be installed in such a way as to minimize root damage. Also, since the desired effect of the barrier is to prevent construction traffic from entering the trees critical root zone, the barrier should be kept in place until all site servicing and house construction has been completed.
To protect breeding birds, any tree or shrub removal should occur between April 15th and July 31st, unless a breeding bird survey conducted within five days of the woody vegetation removal identifies no active nests in the trees or shrubs.
The above tree retention can be enhanced through:
minimizing the extent of vegetation removal as much as possible; pruning of branches on trees to be retained to improve their condition and anticipated longevity;
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 18 MUNCASTER ENVIRONMENTAL PLANNING INC.
to encourage re-vegetation close cutting of existing vegetation during clearing as oppose to grubbing in areas where woody vegetation removal is required for access or work areas only; where feasible, transplanting of regenerating stems where they will be in conflict with building envelopes; and, additional planting of native trees on a lot by lot basis. To provide a natural appearance, trees should be planted in a random, cluster fashion rather than in a grid system. Native species present on the site such as sugar maple, basswood, bur oak, white spruce and white pine should be utilized. Due to the clay soils in the east portion of the site tree and shrub species that have a high water demand are generally not recommended. These species include willows, poplars and elm.
Schedule of Proposed Works
It is proposed to remove the woody vegetation not proposed for retention in 2013, before the breeding bird season. City of Ottawa staff (Forester – Planning) is to be contacted at least two business days prior to any tree removal so that staff have the opportunity to verify that the protective fencing has been properly constructed.
5.2 Aquatic Habitat
The majority of the intermittent on-site channel will be realigned as shown on Map 2. The realignment will require the approval of Mississippi Valley Conservation. In addition new channels will be created, some in areas of existing swales, in the north and central portions of the site.
The realignments and new channels will be installed prior to construction of the balance of the subdivision. The realigned channels will be protected with silt fencing erected prior to site alterations on the adjacent lots. This will avoid the potential for migration in surface flow of sedimentation and other contaminants into the new channels and ultimately downstream habitat. It is important that the construction and silt fencing are installed prior to other site disturbances. The fencing should be regularly inspected and maintained to ensure proper function.
No building footprint or other site disturbance will be within 15 metres of the on-site channels. This setback will be allowed to naturalize over time. In the majority of the site the naturalized setback will provide much more protection and buffer function than the current agricultural land use on the majority of the site. In the southwest forest care will be taken during excavation of the new channel to retain trees on the south side of the corridor. This will maximize the shading function of the retained trees.
Other recommended measures for the channel realignments are:
The new channels are to be dug well in advance so the banks can be stabilized with vegetation prior to connections and flow conveyance;
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 19 MUNCASTER ENVIRONMENTAL PLANNING INC.
As with the new channels, the new culverts are to be installed in advance. All new culverts are to be embedded a minimum of ten percent and stabilized with rock protection at each end. Smaller and rounded material will be placed over the larger rock protection to provide more habitat utilization potential. It is very important that the rock protection be placed at an elevation that will not create a potential barrier to fish movement during low flow periods;
Wherever possible the channel relocations should be done when the channel is dry and must be done outside of the sensitive March 15th to June 30th period for the protection of on-site and downstream habitat. If a connection is required while exposed soil is present, geotextile liner or a similar effective method is required to ensure no downstream sediment inputs occur;
If rock removal is required, it is important that the rock be excavated in a manner that does not result in a smooth bed surface. Dips in the bed elevation are required;
The new channel profile should contain no sections where the gradient is steeper than 1.5 percent. This is not anticipated to be a concern on the relatively flat site;
The new channel is to be designed with a low-flow channel. The low flow channel should have a slight meandering within the channel corridor. Small boulders, pools and small pieces of woody debris including logs with roots wads should be added to increase the in-stream structure of the new channel;
The original channel is to be walked several times and all fish netted and released into the new channel prior to disturbances along the portions of the existing channel not to be retained. Boulders and woody material are generally not present in the existing on-site channel but any in-stream structure such as this should be relocated to the new channel;
All material to be placed in the new channels, including salvaged material, is to be clean and free of fines;
All spoil should either be removed from the site or spread away from the top-of-banks and seeded. All disturbed areas should be vegetated by seeding with grasses to prevent soil erosion. Silt fencing should be placed between the spread spoil and the new channels if exposed soil is still present when the new channels are on-line;
Additional mitigation measures to minimize the potential for inputs of sediments and other contaminants into the watercourse and the environment in general include proper maintenance on construction equipment with respect to refuelling, washing and fluid changes, and proper disposal of fluids, filters and other waste material; and,
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 20 MUNCASTER ENVIRONMENTAL PLANNING INC.
Monitoring is to be completed frequently, especially during any periods of flow when in- water construction is on-going. Any water quality issues such as elevated turbidity levels are to be address immediately with cessation of work until proper sediment and erosion controls are in place.
5.3 Stormwater Mitigation
The proposed drainage plan for the site has been designed so existing base flows and quantities are maintained.
During the detailed design process for the proposed development, the methodology outlined in the Ministry of Environment Stormwater Management Practices Planning and Design Manual will be implemented. This methodology promotes water management from an environmentally sustainable perspective.
Low gradient, grassed swales will provide an opportunity for settling, absorption, filtration and infiltration of the stormwater before entering a stormwater management pond in the northeast corner of the site for quantity control. The management pond will outlet to the roadside ditch along Marchurst Road. This will reduce the peak flows and volume of stormwater runoff from the developed site. The preservation of existing drainage patterns and maintaining stormwater runoff volume to near pre-development levels will result in minimal impact to the moisture regime.
No notable increase in runoff volumes is anticipated given the sandy nature of much of the overburden on site that will allow for infiltration.
The following Best Management Practices (BMP's) will be implemented on the site:
Lot Level Controls
Roof leaders will be directed onto grassed areas, as opposed to a hard surfaced driveway. Discharge to rear yards will be implemented wherever possible, increasing the likelihood of particle filtration and runoff re-absorption. The use of soak away pits will be investigated.
At the lot level, the effects of runoff reduction measures are enhanced by minimizing lot grades to allow greater ponding of stormwater and promote natural infiltration. Due to the natural topography or relief of the site, very little grading of each lot will be required, thus allowing natural filtration and absorption to continue while maintaining base flows and reducing total suspended sediment levels. Plus, the lot sizes of the development will also help ensure that most of the site will remain in its natural state.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 21 MUNCASTER ENVIRONMENTAL PLANNING INC.
Conveyance Control
Perhaps one of the best conveyance controls available is the use of low gradient grassed waterways having flattened side slopes. The conveyance system proposed for this development is typically a grassed channel having a minimum 3:1 side slope ratio, set at a minimum gradient of 0.5% to 1%. The flat grades help to reduce flow velocities, reducing erosion potential. The grassed bottoms and side slopes act as a filter for any suspended particulate matter as well as promote re-absorption. The net effect is that flows are attenuated, particulate matter is filtered and overall flow volumes are reduced.
Some of the site where the channels will be placed is underlain by sand, which again will assist in filtration, absorption and reduction of flow volumes that will minimize erosion. All erosion prone areas will be protected using rip rap. Areas disturbed by construction will be topsoiled and seeded in a timely manner.
The use of silt fence barriers and straw bale check dams during construction will help filtering out suspended solids and promote absorption.
Oils resulting from driveways and the roads will be very small in amount and are not anticipated to be a problem given that this is a rural residential development and any material will be filtered in the grass channels.
5.4 Erosion and Sediment Controls
The objective with respect to erosion and sediment controls will be to ensure that the surface water runoff leaving the site is not degraded with respect to water quantity or quality. An erosion and sediment control plan will be prepared as part of the detailed design package. During construction, existing stream and conveyance systems can be exposed to significant sediment loadings. Seepage barriers such as silt fencing, straw bale check dams and other sediment and erosion control measures will be installed to reduce as much as possible sediment loadings during construction in any temporary drainage ditches and around disturbed areas during construction and stockpiles of fine material. Although little groundwater is expected during construction, any groundwater will be pumped into a proper filter mechanism such as a sediment trap or filter bag prior to release to the environment. Stockpiles of cleared materials as well as equipment fuelling and maintenance areas will be located a minimum of 30 metres from swales and other conveyance routes. Construction vehicles will leave the site at designated locations. Exits will consist of a bed of granular material, to minimize the tracking of mud off-site. Properly constructed and maintained spill pans and tarps will be required for all machinery and storage tanks utilized on the site.
A qualified inspector will conduct frequent visits during construction to ensure that the contractor is constructing the project in accordance with the design drawings and mitigation measures are being implemented and maintained as specified. These control measures must be properly maintained to maximize their function during construction. Silt fencing may require
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 22 MUNCASTER ENVIRONMENTAL PLANNING INC. removal of sediment and repairs. The inspector must ensure that construction vehicles and chemicals, fuels and other potentially hazardous materials remain in designated areas.
All sediment and construction fencing should be removed following construction, providing there is no exposed soil or other potential sources of sedimentation.
The extent of exposed soils shall be kept to a minimum at all times. All sodding and seeding is to be conducted correctly and as soon as weather and construction activity permits.
During operation of the residences erosion and sediment control will focus on best management practices such as grassed swales with a reduced slope and direction of roof and rear yard runoff to the rear of the lots.
6.0 CUMULATIVE EFFECTS and SUMMARY
The Canadian Environmental Assessment Agency (CEAA) defines cumulative effects as…”the effects on the environment caused by an action in combination with other past, present, and future human actions…” They occur when two or more project-related environmental effects, or two or more independent projects, combine to produce an augmented effect. These cumulative effects may be positive or negative.
With proper implementation of the mitigation measures described in this report it is anticipated that the construction and operation of the rural residential subdivision will not have a detectable impact on the natural environment or increase the potential for cumulative effects. To achieve this objective it is important that as much of the northwest and southwest deciduous forests as possible remain in their existing condition.
The natural environment features of the site are the deciduous forests, associated wildlife habitat and scattered trees on the balance of this predominately agricultural site. A very small portion of the Carp Hills Natural Area is located in the northwest portion of the site. In addition, the core of the Natural Area and the Carp Hills regionally-significant candidate Area of Natural and Scientific Interest are located to the west of the site. Given the proposed ‘no-touch’ setbacks from the west boundary of the site, the low density of the development and adjacent rural residential developments, it is anticipated that there will be no notable impacts on the significant natural heritage features and functions of the Carp Hills Natural Area or regionally significant candidate Area of Natural and Scientific Interest.
The 0.8 ha lot sizes will assist in retention of trees and bedrock outcroppings within the southwest and northwest deciduous forests. Other groves of trees will be retained on the non- forested portion of the site. Regenerating stems could be transplanted where they cannot be retained in their present location due to conflicts with development envelopes. As plantings of native woody vegetation mature, the natural cover of the non-forested portion of the site will increase over the existing abundance of agricultural fields.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 23 MUNCASTER ENVIRONMENTAL PLANNING INC.
The channel in the south portion of the site will be realigned. No building footprints or other disturbances will be within fifteen metres of the channel or other channels created on-site. This setback will be allowed to naturalize over time, providing greater stream cover and natural conditions than the current conditions. Silt fencing, established prior to any earth moving, will protect the water quality of the channel during construction.
Best management practices for stormwater will be instituted to protect the on-site and downstream environmental features during construction and operation of the rural residential development.
7.0 REFERENCES
Banfield, A. W. F. 1974. The Mammals of Canada. University of Toronto Press. ISBN 0-8020- 2137-9. 438 pp.
Brunton, D.F. 1995. Life Science Areas of Natural and Scientific Interest in Site District 6-12. Ontario Ministry of Natural Resources, Eastern Region, Kemptville. 191 pp. + map
Brunton, D.F. 1997. Summary: Natural Area Reports for Natural Areas West of Rideau River (500 series). Prepared for the Regional Municipality of Ottawa-Carleton, Planning and Development Approvals Department. 164 pp.
City of Ottawa. 2003. City of Ottawa Official Plan. As adopted by City Council, May, 2003. Publication: 1-28. 227 pp & Sched.
Ehrlich, P. R., D. S. Dobkin and D. Wheye. 1988. The Birder's Handbook. Simon & Schuster Inc., New York, New York. 785 pp.
Oldham, M.J., W.D. Bakowsky and D.A. Sutherland. 1995. Floristic Quality Assessment System for Southern Ontario. Natural Heritage Information Centre, Ontario Ministry of Natural Resources. 68 pp.
Ontario Ministry of Natural Resources. 2010. Natural Heritage Reference Manual for Natural Heritage Policies of the Provincial Policy Statement, 2005. Second Edition. March 2010. 233 pp.
Robinson Consultants Inc. 2004. Carp River Watershed/Subwatershed Study. December, 2004. Prepared for the City of Ottawa. Project No. 00056. 233 pp & append.
Schut, L.W. and E.A. Wilson. 1987. The soils of the Regional Municipality of Ottawa-Carleton (excluding the Ottawa Urban Fringe). Report No. 58 of the Ontario Institute of Pedology.
Stantec Consulting Limited. 2012. Marchurst Estates Kanata, City of Ottawa. Preliminary Stormwater Management Report. July 23rd, 2012. Report No. 160400965/83.
06/03/13 EIS/TREE CONSERVATION REPORT– CONCESSION I, LOTS 18 & 19 (KANATA) Page 24