13.          JOCK RIVER REACH 1 SUBWATERSHED STUDY AND BARRHAVEN SOUTH MASTER SERVICING STUDY

 

ÉTUDE SUR LE SOUS-BASSIN HYDROGRAPHIQUE DU TRONÇON 1 DE LA RIVIÈRE JOCK ET ÉTUDE SUR LE PLAN DIRECTEUR DE VIABILISATION DE BARRHAVEN SUD

 

 

 

Committee recommendationS

 

That Council:

 

1.         Approve the Jock River Reach 1 Subwatershed Study (Stantec, January 2007).

 

2.         Approve the Barrhaven South Conceptual Fish Habitat Compensation Plan (Niblett, January 2007) and the use of City land known municipally as 3300 Cedarview Road for the creation of new fisheries habitat area.

 

3.         Approve the recommended projects identified in the Barrhaven South Master Servicing Study prepared by Stantec, illustrated in Document 4, in accordance with the requirements of the Ontario Environmental Assessment Act.

 

4.         Direct Planning, Transit and Environment staff to finalize the Barrhaven South Master Servicing Study and proceed with the 30-day public review period, in accordance with the Ontario Environmental Assessment Act and as a prelude to the initiation of the detailed design.

 

 

RecommandationS du Comité

 

Que le Conseil municipal approuve :

 

1.         L’étude sur le sous-bassin hydrographique du tronçon 1 de la rivière Jock (Stantec, janvier 2007);

 

2.         Le Plan de compensation conceptuel sur l’habitat du poisson de Barrhaven Sud (Niblett, janvier 2007) et l’utilisation des propriétés de la Ville situées au 3 300, chemin Cedarview, pour la création d’une nouvelle zone d’habitat du poisson;

 

3.         Les projets recommandés indiqués dans l’étude sur le Plan directeur de viabilisation de Barrhaven Sud préparée par Stantec et illustrée dans le Document 4, conformément aux exigences de la Loi sur l’évaluation environnementale de l’Ontario;

 

4.                  Demande au personnel d’Urbanisme, Transport en commun et Environnement de finaliser l’étude sur le Plan directeur de viabilisation de Barrhaven Sud et d’aller de l’avant avec la période d’examen public de 30 jours, conformément à la Loi sur l’évaluation environnementale de l’Ontario et à titre de prélude au lancement de la conception détaillée.

 

 

 

Documentation

 

1.      Deputy City Manager's report Planning, Transit and the Environment dated
24 January 2007 (ACS2007-PTE-POL-0004).

Report to/Rapport au :

 

Planning and Environment Committee

Comité de l'urbanisme et de l'environnement

 

and Council / et au Conseil

 

24 January 2007 / le 24 janvier 2007

 

Submitted by/Soumis par : Nancy Schepers, Deputy City Manager/

Directrice municipale adjointe,

Planning, Transit and Environment/Service de l'urbanisme, du transport en commun et de l'environnement 

 

Contact Person/Personne ressource : Dennis Jacobs, Director

Planning, Environment and Infrastructure Policy/Politiques d’urbanisme, d’environnement et d’infrastructure

(613) 580-2424 x 25521, Dennis.Jacobs@ottawa.ca

 

Barrhaven (3), Gloucester-South Nepean (22)

Ref N°: ACS2007-PTE-POL-0004

 

 

SUBJECT:

JOCK RIVER REACH 1 SUBWATERSHED STUDY AND BARRHAVEN SOUTH MASTER SERVICING STUDY

 

 

OBJET :

ÉTUDE SUR LE SOUS-BASSIN HYDROGRAPHIQUE DU TRONÇON 1 DE LA RIVIÈRE JOCK ET ÉTUDE SUR LE PLAN DIRECTEUR DE VIABILISATION DE BARRHAVEN SUD

 

 

REPORT RECOMMENDATION

 

That Planning and Environment Committee recommend City Council:

 

1.         Approve the Jock River Reach 1 Subwatershed Study (Stantec, January 2007).

 

2.         Approve the Barrhaven South Conceptual Fish Habitat Compensation Plan (Niblett, January 2007) and the use of City land known municipally as 3300 Cedarview Road for the creation of new fisheries habitat area.

 

3.         Approve the recommended projects identified in the Barrhaven South Master Servicing Study prepared by Stantec, illustrated in Document 4, in accordance with the requirements of the Ontario Environmental Assessment Act.

 

4.         Direct Planning, Transit and Environment staff to finalize the Barrhaven South Master Servicing Study and proceed with the 30-day public review period, in accordance with the Ontario Environmental Assessment Act and as a prelude to the initiation of the detailed design.

 

RECOMMANDATION DU RAPPORT

 

Que le Comité de l’urbanisme et de l’environnement recommande au Conseil municipal :

 

1.         d’approuver l’étude sur le sous-bassin hydrographique du tronçon 1 de la rivière Jock (Stantec, janvier 2007);

 

2.         d’approuver le Plan de compensation conceptuel sur l’habitat du poisson de Barrhaven Sud (Niblett, janvier 2007) et l’utilisation des propriétés de la Ville situées au 3 300, chemin Cedarview, pour la création d’une nouvelle zone d’habitat du poisson;

 

3.         d’approuver les projets recommandés indiqués dans l’étude sur le Plan directeur de viabilisation de Barrhaven Sud préparée par Stantec et illustrée dans le Document 4, conformément aux exigences de la Loi sur l’évaluation environnementale de l’Ontario;

 

4.         de demander au personnel d’Urbanisme, Transport en commun et Environnement de finaliser l’étude sur le Plan directeur de viabilisation de Barrhaven Sud et d’aller de l’avant avec la période d’examen public de 30 jours, conformément à la Loi sur l’évaluation environnementale de l’Ontario et à titre de prélude au lancement de la conception détaillée.

 

 

EXECUTIVE SUMMARY

 

Assumptions and Analysis:

 

The Barrhaven South Community Design Plan (CDP) was approved by City Council on June 28, 2006.  One of the approved recommendations directed staff to bring forward for approval the required Subwatershed Study for the Jock River Reach 1, the Conceptual Fish Habitat Compensation Plan, and the Master Servicing Study. These supporting studies have now been completed and are the subject of this report for approval.

 

The City of Ottawa and the principal landowners within Barrhaven South undertook the following technical studies, as co-proponents, following the Class Environmental Assessment (EA) process in support of the Barrhaven South Community Design Plan:

 

·           Jock River Reach 1 Subwatershed Study (January 2007)– Stantec Consulting Ltd., Niblett Environmental Associates Inc., Parish Geomorphic

·           Barrhaven South Conceptual Fish Habitat Compensation Plan (January 2007) – Niblett Environmental Associates Inc.

·           Barrhaven South Master Servicing Study - Stantec Consulting Ltd.


 

The subwatershed study has developed a stormwater management and natural environment plan for north of the Jock River, south of the Jock River and the Jock River Corridor to assist with future studies and development requirements.  The Barrhaven South Conceptual Fish Habitat Compensation Plan (CFCP) identifies fish habitat restoration and enhancement measures to address the fish habitat losses associated with the development of Barrhaven South.  The Barrhaven South Master Servicing Study has identified an internal servicing scheme for water, sanitary, storm drainage and stormwater management servicing that supports the land uses and development densities approved through the Barrhaven South Community Design Plan.  The following infrastructure projects have been recommended for the Barrhaven South development area following the Class EA process for Schedule B undertakings:

 

·           Wastewater collection system 

·           Water distribution system

·           Enclosure/partial enclosure of four watercourses (Todd, East Clarke, West Clarke and Corrigan municipal drains/tributaries)

·           Construction of three stormwater detention facilities and associated storm drainage collection systems, including:

o          Corrigan SWM Pond and associated storm sewers (Schedule B)

o          Todd SWM Pond and associated storm sewers (Schedule B)

o          Clarke SWM Pond and associated storm sewers (Schedule B)

 

The Master Servicing Study has also identified constraints that will influence the storm drainage servicing of the site.  Subsurface investigations have identified soil conditions (compressible silty clays) which limit the extent to which the site may be raised.  Preliminary design completed for the Master Servicing Study has assumed a maximum grade raise of 1.5 meters, however, further detailed geotechnical investigations will be required during detailed design to confirm the permissible grade raise. and to determine the extent to which practices such as pre-loading or surcharging will be required to safely accommodate the proposed grade raise. Such measures will require additional time to prepare the site for servicing.

 

Given the low lying areas in the northern portion of the study area and the grade raise restrictions noted above, much of the storm sewer system will have minimal cover and a portion of the system will be subject to permanent standing water.  These conditions will preclude the use of standard depth basements over a significant portion of the study area.

 

The approval of these technical studies will facilitate the processing and approval of development applications in the area. 

 

Financial Implications:

 

The majority of projects identified in the technical studies will be financed through Development Charges, developers or existing programs through Council’s budgetary approval process.


 

Site constraints arising from soil conditions that limit grade raises in combination with low lying areas over a large portion of the site will result in permanent standing water in a significant portion of the storm sewer system.  This will result in signficantly increased costs to the City to own, operate and maintain the affected sewers due to the need for regular pumping to draw down the sewers and/or other measures to manage the increased potential for sedimentation in the pipes.

 

Public Consultation/Input:

 

The consultation program fulfilled the consultation requirements specified in the Municipal Engineers Association Class Environmental Assessment document for Schedule B projects.  A total of four open houses/ workshops were conducted at key project milestones.  Individual and collective meetings with other City staff, Rideau Valley Conservation Authority, and provincial and federal agencies to discuss technical requirements and comments were held on numerous occasions throughout the development of both studies. 

 

The Barrhaven South Master Servicing Study will be finalized after City Council approves the recommended projects (Recommendation 3).  Notices of Completion will be published for both the Subwatershed Study and Master Servicing Study notifying the public of the availability of the reports and the 30-day public review period.

 

 

RÉSUMÉ

 

Hypothèses et analyse :

 

Le 28 juin 2006, le Conseil municipal a approuvé le Plan de conception communautaire (PCC) de Barrhaven Sud. Dans une des recommandations approuvées, on demandait au personnel de présenter pour fins d’approbation l’étude sur le sous-bassin hydrographique requise pour le tronçon 1 de la rivière Jock, le Plan de compensation conceptuel sur l’habitat du poisson et l’étude sur le Plan directeur de viabilisation. Ces études complémentaires sont maintenant terminées et font l’objet du présent rapport qui doit être approuvé.

 

La Ville d’Ottawa et les principaux propriétaires de Barrhaven Sud ont entrepris les études techniques suivantes, à titre de coproposants, à la suite du processus d’évaluation environnementale (ÉE) de portée générale à l’appui du Plan de conception communautaire de Barrhaven Sud :

 

.           Étude sur le sous-bassin hydrographique du tronçon 1 de la rivière Jock (janvier 2007) – Stantec Consulting Ltd., Niblett Environmental Associates Inc., Parish Geomorphic;

.           Plan de compensation conceptuel sur l’habitat du poisson de Barrhaven Sud (janvier 2007) – Niblett Environmental Associates Inc.;

.           Étude sur le Plan directeur de viabilisation de Barrhaven Sud – Stantec Consulting Ltd.

 

Dans le cadre de l’étude sur le sous-bassin hdrographique, on a établi un plan d’environnement naturel et de gestion des eaux pluviales pour le nord de la rivière Jock, le sud de la rivière Jock et le corridor de la rivière Jock pour aider aux études futures et aux besoins d’aménagement. Le Plan de compensation conceptuel sur l’habitat du poisson de Barrhaven Sud soulève les mesures d’amélioration et de restauration de l’habitat du poisson à prendre pour remédier aux pertes de l’habitat du poisson associées à l’aménagement de Barrhaven Sud. Dans le cadre de l’étude sur le Plan directeur de viabilisation de Barrhaven Sud, on a déterminé un plan de service interne pour les services publics d’eau, d’égouts sanitaires et pluviaux et de gestion des eaux pluviales, lequel appuie l’utilisation des terrains et les espaces d’aménagement approuvés par le Plan de conception communautaire de Barrhaven Sud. Les projets d’infrastructure suivants ont été recommandés pour la zone de développement de Barrhaven Sud à la suite du processus d’ÉE de portée générale pour les initiatives de l’annexe B :

 

.           réseau de collecte des eaux usées;

.           réseau de distribution d’eau;

.           isolement/isolement partiel de quatre cours d’eau (drains municipaux/affluents de Corrigan, Todd, East Clarke, West Clarke);

.           construction de trois installations de retenue des eaux pluviales et de réseaux connexes de collecte et de drainage des eaux pluviales, y compris :

○     le bassin de GEP Corrigan et les égouts pluviaux connexes (annexe B),

○     le bassin de GEP Todd et les égouts pluviaux connexes (annexe B),

○     le bassin de GEP Clarke et les égouts pluviaux connexes (annexe B).

 

Dans l’étude sur le Plan directeur de viabilisation, on a également déterminé les contraintes qui influenceront les services publics de drainage pluvial du site. Les études souterraines ont permis de déceler les conditions du sol (argile limoneuse compressible) qui limitent la mesure dans laquelle l’emplacement peut être soulevé. Une fois la conception préliminaire terminée pour l’étude sur le Plan directeur de viabilisation, on a présumé une élévation maximale du niveau de 1,5 mètre. Toutefois, d’autres études géotechniques détaillées seront nécessaires pendant la conception détaillée afin de confirmer l’élévation admise du niveau et de déterminer la mesure dans laquelle les pratiques comme le préchargement ou le surchargement seront nécessaires pour réaliser en toute sécurité l’élévation proposée du niveau. De telles mesures nécessiteront plus de temps pour préparer l’emplacement pour les services.

 

Étant donné les régions basses dans la partie nord de la zone d’étude et les restrictions quant à l’élévation du niveau susmentionnées, le réseau d’égouts pluviaux sera en grande partie peu couvert et une partie du réseau sera assujettie à des eaux dormantes permanentes. Ces conditions empêcheront l’utilisation des sous-sols de profondeur standard dans une importante partie de la zone d’étude.

 

L’approbation de ces études techniques facilitera le traitement et l’approbation des demandes d’aménagement dans le secteur.

 

Répercussions financières :

 

La majorité des projets soulevés dans les études techniques seront financés par les redevances d’aménagement, les promoteurs ou les programmes actuels, conformément au processus d’approbation des budgets du Conseil.

 

Les contraintes du site découlant des conditions du sol qui limitent les élévations du niveau en combinaison avec les régions basses sur une grande partie du site auront pour conséquence la présence d’eaux dormantes permanentes dans une importante partie du réseau d’égouts pluviaux. Cela entraînera une augmentation considérable des coûts à la Ville pour acquérir, faire fonctionner et entretenir les égouts touchés en raison du besoin d’un pompage régulier pour abaisser le niveau des égouts et/ou d’autres mesures pour gérer la possibilité accrue d’une sédimentation dans les tuyaux.

 

Consultation publique / commentaires :

 

Le programme de consultation a répondu aux besoins de consultation précisés dans le document de l’évaluation environnementale de portée générale de la Municipal Engineers Association pour les projets de l’annexe B. Au total, quatre consultations publiques/ateliers ont été tenus à des étapes marquantes du projet. On a organisé à plusieurs occasions tout au long du développement des études des réunions individuelles et collectives avec d’autres membres du personnel de la Ville, l’Office de protection de la nature de la vallée Rideau et des organismes provinciaux et fédéraux afin de discuter des exigences techniques et des commentaires reçus.

 

L’étude sur le Plan directeur de viabilisation de Barrhaven Sud sera finalisée une fois que le Conseil municipal aura approuvé les projets recommandés (Recommandation 3). Des avis d’achèvement seront publiés pour l’étude sur le sous-bassin hydrographique et l’étude sur le Plan directeur de viabilisation informant le public de la disponibilité des rapports et de la période d’examen public de 30 jours.

 

 

BACKGROUND

 

Barrhaven South is an area of approximately 500 hectares in size located in the southern end of the urban area of Ottawa, as illustrated in Document 1.  The Barrhaven South study area is defined by the Jock River to the north, Highway 416 to the west, Jockvale Road and Greenbank Road to the east, and the urban area boundary to the south.  Barrhaven South is west of, and adjacent to, the developing community of Stonebridge, and is south of the South Nepean Town Centre.  In January 2005, a consultant team, working on behalf of the principal landowners within the Barrhaven South boundary, in concert with the Planning, Transit and Environment Department, initiated the Barrhaven South Community Design Plan (CDP).  As part of the development of the CDP, the Jock River Reach 1 subwatershed, transportation master plan and master servicing studies were undertaken to identify the environmental, roadway, transit and infrastructure servicing requirements to guide and support the preferred land use plan.  All of these technical studies followed the Municipal Engineers Association (MEA) Class Environmental Assessment process.

 

The Barrhaven South Community Design Plan (CDP) and Transportation Master Plan were completed and approved by Council in June 2006 (http://ottawa.ca/calendar/ottawa/citycouncil/pec/2006/06-13/ACS2006-PGM-POL-0042.htm).  The subwatershed and master servicing studies were not finished at that time.  Council approved staff's recommendation to bring forward the master servicing study, the subwatershed study for Reach 1 of the Jock River and conceptual fish compensation plan for Council approval.  Council approved Recommendation 4 of the Barrhaven South Community Design Plan Report that directed Legal Services to bring forward the Barrhaven South draft Official Plan Amendment implementing by-law to City Council for approval once the three studies had received City Council approval.

 

The Jock River Reach 1 Subwatershed Study and Barrhaven South Conceptual Fish Habitat Compensation Plan have now been completed (Document 2, distributed under separate cover) and as per Recommendations 1 and 2 of this report, approval of these documents are recommended.  As per Recommendation 3 of this report, staff recommends approval of the wastewater, water, storm drainage and stormwater management projects identified through the Barrhaven South Master Servicing Study (Document 4). The approval of these technical studies will allow for the Official Plan Amendment to proceed to Council, facilitating the processing and approval of development applications in the Barrhaven South area.  The purpose of this report is to provide a summary of the study process that lead to the environmental and infrastructure servicing recommendations. 

 

 

DISCUSSION

 

The Jock River Reach 1 Subwatershed Study and Barrhaven South Master Servicing Study followed an integrated planning approach such that the environmental and preliminary servicing requirements were identified and integrated into the development of the preferred land use plan for Barrhaven South.  Detailed analysis was then undertaken based on the preferred concept plan to sufficiently define the environmental and infrastructure servicing requirements consistent with applicable policies, regulations and engineering standards.  Although separate documents have been produced, the technical studies were planned and coordinated as an integrated master planning exercise. 

 

The City of Ottawa and the principal landowners within Barrhaven South are co-proponents for the required Class Environmental Assessments.  The subwatershed and master servicing studies have completed Phases 1 and 2 of the MEA Class Environmental Assessment process following the Master Plan approach.  The subwatershed study followed “Approach #1” of the Master Planning approach whereby a broad level of assessment has been undertaken such that projects identified would require further assessment under the Class EA.  The Master Servicing Study followed “Approach #2” whereby the level of assessment, consultation and documentation are sufficient to fulfill the requirements for Schedule B projects.  Following the posting of the Notice of Completion and the conclusion of the 30-day public review period, all Class EA requirements will have been met and the identified projects may proceed to detailed design and construction. 


For the area north of the Jock River, the conceptual stormwater management option identified in the subwatershed study would be subject to completing the EA requirements and approvals in the future.

 

A summary of the study methodology, analysis and recommendations associated with the three technical studies is provided below.

 

Jock River Reach 1 Subwatershed Study

 

The Barrhaven South community falls within Reach 1 of the Jock River subwatershed area.  The subwatershed boundary is larger than the CDP area as it follows a natural drainage area boundary.  Document 1, Study Area Figure, illustrates the subwatershed boundary that includes lands north of the Jock River within the existing Barrhaven community and adjacent vacant urban lands, east of Highway 416.  The subwatershed has a total area of approximately 2,300 hectares, one half of which is already developed.  The majority of the subwatershed is in the urban area with approximately 711 ha of vacant land located north of the Jock River and approximately 360 ha vacant land situated south of the Jock River. 

 

The Jock River Reach 1 subwatershed study provides the environmental and conceptual stormwater management requirements for the Barrhaven South community and the undeveloped urban lands north of the Jock River, straddling Strandherd Drive.  The management strategy aims to protect, restore or enhance the significant natural features and functions identified in the subwatershed while accommodating development, over the long-term.  As part of the subwatershed study, a Conceptual Fish Habitat Compensation Plan (CFCP) has been prepared to identify fish habitat restoration and enhancement measures to address the fish habitat losses associated with the development of Barrhaven South. 

 

The Jock River Reach 1 subwatershed planning process was comprised of four main phases: 1) Characterization of Existing Environmental Conditions; 2) Establishment of Subwatershed Goals and Objectives; 3) Development of the Preferred Management Strategy; and, 4) Implementation Strategy.  Reach One of the Jock River falls within the Rideau River watershed.  The Council approved Lower Rideau River Watershed Strategy (http://ottawa.ca/calendar/ottawa/citycouncil/pec/2006/10-24/ACS2006-PGM-POL-0080.htm) was a guiding document in the development of the subwatershed plan.  The main phases and outcome of the subwatershed process are summarized below.

 

Existing Environment Conditions

 

The existing natural resources within the subwatershed were identified and assessed to determine significant features and functions within the study area.  Investigations were conducted in the areas of hydrology, terrestrial, aquatic, water quality, fluvial geomorphology, and hydrogeologic resources.  The level of detail differed for lands north and south of the Jock River, in that more detailed field investigations and analysis were undertaken for the lands south of the Jock River in association with the Barrhaven South Community Design Plan. 

 

Document 3, Environmental Constraints and Opportunities map and key findings, illustrates the important natural features within the subwatershed, such as woodlands and watercourses.  Key environmental findings are highlighted below and summarized in Document 3:

 

Tributaries:

·           North of the Jock River, the main tributaries are O’Keefe Drain, Foster Ditch and Fraser Clarke Drain.

·           South of the Jock River, the main tributaries are the West Clarke Drain, East Clarke Drain, Todd Drain and Corrigan tributary.

·           All tributaries to the Jock River support fisheries and are considered fish habitat.

·           The tributaries provide only a highly seasonal and marginal fish habitat for a handful of warm water tolerant fish species.

 

Terrestrial Resources:

·           A total of 28 woodlands exist in the subwatershed.  A total of nine woodlands were identified as significant consistent with the findings of the Urban Natural Areas Environmental Evaluation Study.  These include Urban Natural Areas #49 (W7), #50 (W44), #57 (W1 W2), #58 (W10), #60 (W43), #183 (W50).

·           Significant species reported or observed include one federal (butternut), one provincial (greater redhorse fish species) and fourteen regionally rare species.

 

Jock River:

·           Jock River is highly productive fisheries resource that contains healthy populations of naturally reproducing game fish such as muskellunge. 

·           A number of important and/or critical fish habitat areas within the main stem of the Jock River have been identified within Reach 1.

·           Jock River water quality is highly impaired and does not meet provincial water quality criteria.

·           The Jock River is classified as a Policy 2 watercourse for phosphorus, which requires a net reduction in phosphorus loadings to the river.

·           Through the fluvial geomorphology investigation, the meander belt width was determined for the Jock River corridor representing the maximum lateral extent of the channel over time.  Meander belt is considered a hazard constraint that needs to be considered in establishing development setbacks from the river.

 

The environmental constraints and opportunities map was used to develop land use concept alternatives for Barrhaven South.  The Jock River corridor, its floodplain, two tributaries and the two significant woodlands were identified for protection.  The environmental features were used to plan and integrate the parks, open space and stormwater management facilities forming the greenspace network for the community.  Built form and layout design were then developed in concert with the greenspace network ensuring compatibility with natural attributes of the area.

 

Jock River Reach 1 Management Strategy

 

Evaluation and assessment of the various natural resource components of the subwatershed were conducted to understand and identify the important features and functions occurring in the subwatershed. 


This holistic understanding of the health and state of the subwatershed’s ecosystem has led to the preparation of the preferred management strategy for the areas north and south of the Jock River.  The Jock River Reach 1 management strategy consists of three main components: Conceptual Stormwater Management Plan; Natural Environment Plan and Conceptual Fish Habitat Compensation Plan.

 

Stormwater Management Design Criteria

 

Following the analysis of the existing condition of the subwatershed and a series of detailed hydrologic assessments, the criteria for the management of urban runoff were established.  All future stormwater management facilities within Reach 1 must comply with the stormwater management design criteria summarized below.

 

Jock River:

·           No quantity control storage required for flood control purposes as the hydrograph from the subwatershed will peak before the upstream peak in the Jock River.

·           No erosion control storage required to maintain the predevelopment in-stream erosion condition.

·           Quality control storage as per the Ministry of Environment Enhanced Treatment (80% TSS removal), following the integrated SWM approach recommended in the Lower Rideau Watershed Strategy.

 

North of the Jock River - criteria for stormwater management facilities:

·           Quantity control storage as required to meet constraints within existing channels and/or at existing crossings (quantity control/level of control to be determined through further detailed study).

·           Erosion control storage as required to maintain stability and geomorphic function of the existing tributaries, as determined through further detailed study.

·           Quality control storage as per the Ministry of Environment Enhanced Treatment (80% TSS removal).

·           All stormwater management facility outlets will be designed to augment low flows to the extent possible.

 

South of the Jock River - criteria for stormwater management facilities:

·           Quantity control storage as required by the capacity of rehabilitated tributaries.

·           No erosion control storage required; rehabilitated tributaries to be designed to withstand the erosive impulse of stormwater runoff.

·           Quality control storage as per the Ministry of Environment enhanced level treatment (80% TSS removal).

·           All stormwater management facility outlets will be designed to augment low flows to the extent possible.

 

Subwatershed Water Balance:

·           Implement structural infiltration practices (e.g. infiltration trenches) in areas of suitable soil; implement non-structural best management practices (e.g. reduced grading, disconnected impervious areas, promotion of open space and park lands, maximizing vegetative cover) elsewhere in the system to reduce magnitude of runoff volume.

 

Additional analysis was conducted to the satisfaction of the Ministry of Environment that demonstrated the combination of urbanization and stormwater treatment will reduce net loading of phosphorus to the Jock River.

 

Evaluation of Stormwater Management Options

 

A number of stormwater management options were established for north and south of the Jock River.  For north of the Jock River, three stormwater management options were developed for the future urban areas west of Cedarview Road, associated with the O’Keefe Drain and Foster Ditch drainage areas.  For south of the Jock River, five alternative stormwater management options were developed to service the Barrhaven South community.  All of the alternatives were evaluated based on criteria established for the study and presented to the public:  financial (40%); fish and aquatic life (25%); terrestrial vegetation and communities (15%); social/community (20%).  Based on the evaluation of alternatives, a preferred conceptual stormwater management solution was selected for both north and south of the Jock River.  A three-pond configuration, Option 2, as illustrated in Document 5, is proposed to provide stormwater management for the lands north of the Jock River.  Further detailed studies are required to confirm this conceptual stormwater management solution.  

 

For south of the Jock River, a three-pond configuration (Document 4, Figure 6.3, Option 3) was selected as the preferred stormwater management solution for Barrhaven South.  The proposed stormwater management system will enclose the East Clarke drain and Corrigan tributary, and partially enclose the West Clarke and Todd drains.  The remaining open drains will be realigned and rehabilitated, improving habitat for fisheries to meet federal Fisheries Act requirements. Further details on the stormwater management system and realigned tributary corridors are contained within the Barrhaven South Master Servicing Study.  Fisheries enhancement works to address fish habitat losses associated with the enclosure of the tributaries are provided in the Barrhaven South Conceptual Fish Habitat Compensation Plan (CFCP).

 

The area-specific Development Charges By-law 2004-304 for stormwater management facilities and associated drainage systems north and south of the Jock River will need to be revised to account for the new infrastructure projects eligible for Development Charges as identified in the subwatershed and master servicing studies. 

 

North of the Jock River Management Plan

 

Based on the preferred stormwater management option for north of the Jock River, a conceptual stormwater management plan and natural environment plan have been developed individually for the O’Keefe Drain and Foster Ditch drainage areas which are summarized below.  Recommendations have also been made for the Kennedy-Burnett and Fraser Clarke Drain catchment area to be included in a future design study.

 

O’Keefe Drain Catchment Area Stormwater Management Plan

Location

Recommendation

North of Fallowfield Road

Country Lot Development – Use of lot level and conveyance measures to be maximized to achieve SWM design criteria prior to consideration of end-of-pipe facilities.

South of Fallowfield Road

To service lands between Strandherd Drive and McKenna Casey Drive – provide centralized, off-line SWM facility located south of McKenna Casey.

 

O’Keefe Drain Catchment Area Natural Environment Plan

Feature

Recommendation

Woodlot #44

City to protect Woodlot #44 identified as significant woodland currently in private ownership.

Other Terrestrial Features

Conserve and integrate, where feasible, woodlands stands and vegetation associated with woodlots north of Fallowfield Road.

O’Keefe Drain/ Aquatic Habitat

Preserve and enhance aquatic habitat and riparian zone of the tributary through future rehabilitation opportunities.

O’Keefe Drain Corridor

Investigate feasibility of establishing and enhancing the terrestrial linkage along O’Keefe Drain from Jock River corridor to Stony Swamp.

Watercourse Setback Requirement

Setback requirements will be the greater of the100-yr floodline elevation/meander belt width/aquatic habitat buffer

Recreational Trail

Incorporate trail system along O’Keefe Drain as identified in Official Plan and Greenspace Master Plan.

 

Foster Ditch Catchment Area Stormwater Management Plan

Location

Recommendation

North of Maravista

To service the undeveloped lands north of Maravista and existing developments east of Cedarview Road – provide a centralized SWM facility consisting of a wet pond and create an additional area of fish habitat to compensate for loss of habitat due to proposed partial enclosure/alignment of the Foster Ditch

North of McKenna Casey South of Maravista

To service the area north of McKenna Casey Drive between Cedarview and Strandherd not serviced by the Maravista SWM Pond and the area not serviced by the O’Keefe Pond – provide a centralized off-line stormwater facility located south of McKenna Casey Drive.  Existing Foster Pond located at mouth of Foster Ditch to be decommissioned and temporary SWM pond (north of railway on parkland) to be removed.

 

Foster Ditch Catchment Area Natural Environment Plan

Feature

Recommendation

Ditch/Tributary Corridor

Preserve and enhance the aquatic habitat and riparian zone of the tributary through future restoration opportunities.

Watercourse Setback Requirement

Setback requirement will be the greater of the 100-yr floodline elevation/meander belt width/aquatic habitat buffer

 

Kennedy-Burnett/Fraser Clarke Catchment Area Stormwater Management Plan

Location

Recommendation

Kennedy-Burnett SWM Facility/ Fraser Clarke Drain

Future retrofit and expansion of Kennedy-Burnett stormwater management facility to accommodate and treat stormwater runoff from existing and future developments within Kennedy-Burnett and Fraser-Clarke drain catchment area. 

 

Kennedy-Burnett/Fraser Clarke Catchment Area Natural Environment Plan

Feature

Recommendation

Ditch/Tributary Corridor

Preserve and enhance the aquatic habitat and riparian zone of the tributary through future restoration opportunities.

Watercourse Setback Requirement

Setback requirement will be the greater of the 100-yr floodline elevation/meander belt width/aquatic habitat buffer

 

South of the Jock River Management Plan

 

The Barrhaven South development will have three main catchment areas:  the West Clarke, the Todd Drain and the Corrigan Ditch.  Stormwater management and natural environment plans have been developed for each catchment area.  The East Clarke, West Clarke and Todd municipal drains will require abandonment as per the Drainage Act before or in conjunction with development proceeding.  These drains are entirely contained within the urban area and all lands draining into these drains will be urban development consistent with the Council approved Community Design Plan.

 

West Clarke Drain Catchment Area Stormwater Management Plan

Location

Recommendation

West Clarke Drain – north of Cambrian Rd

Provide one centralized stormwater management facility (wet pond) located north of Cambrian Road; partial enclosure of West Clarke drain and full enclosure of East Clarke Drain; rehabilitate/relocate remaining drain, which will be used to convey stormwater runoff to the Jock River.

West Clarke Drain Catchment Area Natural Environment Plan

Feature

Recommendation

Woodlot W1 and W2 (UNA #57)

Protect core area of Woodlot W1 and W2 (UNA #57) as identified as significant woodland and prepare a management plan for the woodland to maintain and enhance environmental quality.

Other terrestrial features

Conserve and integrate, where feasible, vegetation associated with woodlot W3 and other vegetation/hedgerows

Tributary/ Aquatic Habitat

Tributary realignment and restoration including meandering stream/linear wetland.

Tributary Corridor/ Setback

New tributary corridor to be 30 metres wide with 5-metre buffer from top of bank on both sides of the corridor (40 metres).  Establish riparian vegetation along both sides of new channel

Sand and Gravel Resource Area

Any redevelopment plans to maintain existing groundwater recharge function

 

Todd Drain Catchment Area Stormwater Management Plan

Location

Recommendation

Todd Drain at Cambrian Road

Provide one centralized stormwater management facility (wet pond) that straddles Cambrian Road; partial enclosure of Todd Drain; rehabilitate/relocate Todd Drain, which will be used to convey stormwater runoff to the Jock River.

Todd Drain Catchment Area Natural Environment Plan

Feature

Recommendation

Other Terrestrial Features

Conserve and integrate, where feasible, vegetation associated with woodlots W3, W22 and other vegetation/hedgerows.

Tributary / Aquatic Habitat

Tributary realignment and restoration applying natural channel design; fish habitat improvements at mouth and creation of pool-riffle habitat within stream.

Tributary Corridor/ Setback

New tributary corridor to be 30 metres wide with 5-metre buffer from top of bank on both sides of the corridor (40 metres).  Establish riparian vegetation along both sides of new channel.

Organic Soils

City to amend Schedule K – Environmental Constraints of the Official Plan to remove organic soils area situated west of Greenbank Road, southeast of Cambrian Road based on hydrogeologic investigation.

 

Corrigan Drain Catchment Area Stormwater Management Plan

Location

Recommendation

Corrigan Drain at Jock River (city land)

Provide one centralized stormwater management facility (wet pond) located north of Cambrian Road; enclose Corrigan Drain.

Corrigan Drain Catchment Area Natural Environment Plan

Location

Recommendation

Woodlots W7, W10, W50 along shoreline

Protect and conserve significant woodlots W7, W10, W50 (all in city ownership) and City to prepare a management plans for the woodlands to maintain and enhance environmental quality.

Woodlot W4

Environmental investigation of W4 in the rural area.

Other terrestrial features

Conserve and integrate, where feasible, woodlot stands within W4, W9, W11, W12 and other vegetation/hedgerows.

Tributary/ Aquatic Habitat

Tributary realignment and restoration applying natural channel design principles and establish riparian vegetation along new channel corridor.

Watercourse Setback Requirement

No development setback required (situated on parkland/ floodplain).

The Jock River Corridor Management Plan

 

The subwatershed study identified a number of recommendations associated with the Jock River Corridor that are aimed at preserving and improving the terrestrial, aquatic, water quality and recreational aspects of this important river system.

 

Jock River Corridor Management Plan

Feature

Recommendation

Water Quality

Improve Jock River water quality through the implementation of enhanced level treatment of runoff in the urban area.  Promote agricultural Best Management Practices through the Lower Rideau Watershed Strategy implementation committee.

Floodplain

Maintain the regulatory floodplain by not permitting active development within its limits.  Some reduced risk uses such as sports fields and trails may be considered subject to RVCA approval.  Any minor changes to the existing floodplain to proceed on the basis of cut and fill only subject to RVCA approval.

Riparian Corridor

City in partnership with RVC to prepare a Jock River Corridor Riparian Planting Plan to improve and enhance riparian vegetation coverage along the banks and shoreline of the river.

Aquatic Habitat

Continue to protect critical fish habitat and spawning areas along the Jock River and tributary mouths.

Creation of Aquatic Habitat (city lands)

Create pike spawning habitat area adjacent to Foster Dry Pond as compensation for loss of fish habitat in tributaries within Barrhaven South.

Setback Requirement

Development setback for the Jock River will be the greater of:  floodplain, meander belt width, geotechnical, 15 metre top of defined bank or 30 metres from normal high water mark, whichever is greater.  Further erosion and migration rate analysis required along Reach 1 and 2 of the Jock River to confirm meander belt width.

Recreational Pathway

Provide recreational trail along the Jock River as per Official Plan and Greenspace Master Plan.  Recreational pathway to be implemented through the development approval process.  For lands not subject to development, City to investigate opportunities for pathway, where feasible.

 

Implementation Strategy

 

For the lands within the O’Keefe Drain and Foster Ditch catchment areas, an integrated planning approach to confirm the final stormwater and natural environment management plans will be taken.  For the O’Keefe Drain, the first development application received within the catchment area will be required to prepare an Environmental Management Plan (EMP) in collaboration with the City and other agencies including RVCA, MOE, MNR, and DFO as required. 


The EMP will need to conduct further analyses and investigations to confirm and approve the stormwater and natural environment management recommendations for the catchment area.  For the Foster Ditch catchment area, a drainage area study to confirm and plan the stormwater management pond and any associated tributary works/enhancement will be undertaken by the developers in collaboration with the City and other approval agencies.

 

For the retrofit and expansion of the Kennedy-Burnett facility, detailed studies conforming to the Municipal Class EA will be required.  The City of Ottawa will facilitate the study for the expansion and design of the facility in accordance with the criteria and recommendations presented in the subwatershed study. 

 

The Barrhaven South Master Servicing Study, as discussed later in this staff report, has completed more detailed analysis of the recommended three-pond stormwater management concept for Barrhaven South. 

 

The Master Servicing Study will fulfill the Class EA requirements for the stormwater management facilities and watercourse enclosures in Barrhaven South.  The developers will conduct detailed design of the stormwater management facilities and restored tributaries as part of the development approval process.  Tributary enhancement and rehabilitation works must be completed in accordance with the Conceptual Fish Habitat Compensation Plan and receive DFO authorization.  Any proposed tributary enclosure will trigger the detailed design and construction of the fish habitat compensation area on City lands adjacent to the existing Foster detention pond.  This will be the responsibility of the developers.

 

Recommendations for the management and enhancement of the Jock River corridor will be implemented through development approvals, City and RVCA programs and stewardship activities.  It is anticipated that the Lower Rideau Watershed Strategy (LRWS) implementation committee will facilitate a number of the works in collaboration with the community groups and volunteer organizations such as Friends of the Jock River.  Further detailed erosion and migration rate analyses are required along Reach 1 and Reach 2 of the Jock River, particularly in the vicinity of Half Moon Bay, to confirm the preliminary meander belt width provided in the subwatershed study.  This will be the responsibility of the developer(s) as part of the development review process.

 

Overall monitoring of the health and condition of the subwatershed will be incorporated into the Lower Rideau Watershed Strategy integrated monitoring program. 

 

Barrhaven South Conceptual Fish Habitat Compensation Plan

 

The Conceptual Fish Habitat Compensation Plan (CFCP, Niblett 2007) was developed to address proposed fish habitat losses associated with the development of the Barrhaven South CDP area (Document 2, distributed under separate cover).  Applying an integrated environmental and land use planning approach, the subwatershed study recommends enclosure of the East Clarke drain and Corrigan tributary with partial enclosure of the West Clarke and Todd drains.  These full and partial watercourse enclosures are considered harmful alteration, disruption and destruction of fish habitat under the federal Fisheries Act. 


Working with the Department of Fisheries and Oceans, Rideau Valley Conservation Authority and the Ministry of Natural Resources, restoration opportunities were investigated to meet the requirements of the federal Fisheries Act and the study’s environmental objectives.  Restoration opportunities along the remaining tributaries are being proposed, applying natural channel design principles.  A new meandering, low flow channel with be established incorporating fish habitat works such as riffle-pool complexes.  In order to meet a net gain in fisheries and productive capacity within the Jock River system, the creation of a new fish habitat area is being proposed on City lands adjacent to the existing Foster detention pond, north of the Jock River, west of Cedarview Road (refer to Document 3, Environmental Constraints and Opportunities Map).  The surface area of the new fisheries habitat area is approximately 21,500 m2.  The new habitat area will be connected to the Jock River and be designed as spawning habitat for pike and other species.  This land is situated in the floodplain and, as such, has very limited development or program use potential.

 

Real Estate Services was consulted on the proposed use of City lands to accommodate a fish habitat creation area.  An internal and utility circulation was undertaken for the vacant portion of City lands known municipally as 3330 Cederview Road.  There were no requirements or comments for the lands that preclude the creation of fish habitat on the subject property. 

The following comments will be considered during the detailed design stage and associated respondents consulted. 

 

Planning, Environment and Infrastructure Policy Branch:

·           No activity should preclude the long-term use of the lands as public open space.

·           The new habitat area should not impede any future roadway plans for Cedarview Road.  Ottawa Forest and Greenspace Advisory Committee

·           It is imperative that the riparian vegetation be retained and enhanced if it does not interfere with the fish habitat plan.

Hydro Ottawa:

·           Transformer situated on the property owned by Hydro Ottawa.

 

The Department of Fisheries and Oceans has agreed in principle to the Conceptual Fish Habitat Compensation Plan for Barrhaven South.  It will be the responsibility of the developers to undertake the detailed design of the fish spawning area and obtain authorization from DFO in collaboration with the City.  Any use of City land for this purpose will have to be conducted under the authority of a lease or license agreement, with compensation being based on market value.  The City will retain ownership of the land throughout all stages of the project and ultimately own the new fish habitat area.

 

Barrhaven South Master Servicing Study

 

The Barrhaven South Master Servicing Study has been completed to identify an internal servicing scheme for water, sanitary, storm drainage and stormwater management servicing that supports the land uses and development densities approved through the Barrhaven South Community Design Plan.  The study will serve as a guide for the detailed design of infrastructure to support future development applications.  The principal recommendations of the master servicing study are summarized below.

 

Wastewater Servicing

 

The Master Servicing Study completed analyses to consider both internal and external wastewater servicing issues, including an assessment of existing trunk sewer capacity and an evaluation of wasterwater servicing alternatives.

 

Existing Trunk Sewer Capacity:  The existing South Nepean Collector (SNC) and West Rideau Collector (WRC) sanitary trunk sewers service the South Urban Community (SUC) which includes Riverside South, Manotick and Barrhaven South.

 

As current development densities within both the Barrhaven South and Riverside South communities suggest higher densities than those considered in previous servicing studies, a capacity analysis of the SNC and WRC downstream of the SNC’s Jock River crossing was completed to determine whether there was sufficient capacity to accommodate the proposed densities within the Barrhaven South CDP.

 

The existing trunk sewer capacity analysis was completed making use of the City’s H2O Map sewer model considering the build-out condition as per the current Official Plan for all areas tributary to the collectors including Riverside South, Barrhaven South and Manotick. Two modelling scenarios were considered:

 

Scenario 1: - Existing development peak flows were calculated using parameters derived from actual flow monitoring of the trunks while future development peak flows were calculated using standard design parameters (parameters from monitored flows tend to result in lower peak flows than standard design parameters).

Scenario 2: - Existing and future development peak flows were calculated using standard design parameters.

 

Assuming buildout conditions, the modeling results for the two scenarios predict a range of hydraulic grade line (HGL) elevations depending on the flow parameters used to generate existing and future flows.  Results are summarized as follows:

 

Scenario 1: Monitored Parameters for Existing Development and Design Parameters for Future Development

·           Primarily free-flow conditions, with localized areas of minor surcharge in the WRC and SNC.

·           No backwater impacts on the Riverside South and Barrhaven South communities.

 

Scenario 2: Design Parameters for Existing and Future Development

·           Severe surcharge along the WRC and SNC.

·           Backwater impacts on the Riverside South community with potential impacts on the Barrhaven South community.

·           Potential for surface spills along the WRC unless maintenance holes are sealed.

 

Consistent with the findings of other recent evaluations (e.g., Riverside South Master Servicing Study), the above analyses demonstrate that the current proposed level of development within the SUC could potentially lead to surcharge levels along the WRC if flow contributions predicted by design parameters are realized.  However, flows derived from observed (monitored) flow conditions for existing development indicate that currently proposed levels of development could be serviced without causing critical levels of surcharge. 

 

The capacity of the WRC is approximately 3000L/s.  The existing peak flow in the WRC, calculated using design flow parameters, is 1540L/s.  Therefore, the residual peak flow is estimated at 1460L/s.  Assuming a linear growth trend between 2006 and 2021, the residual capacity (1460 L/s) would be used up by the year 2017. This flow condition would be equivalent to an additional 100,594 persons, 62,695 employees and 2040ha of development in the WRC catchment area. This represents an approximate ten year growth horizon before the risk of critical surcharge will occur. This horizon may be extended if existing flow conditions (i.e., based upon on flow monitoring results) are representative of future flow conditions.

 

The identification of potential solutions to address the risk of surcharge as development in the SUC proceeds to build-out was beyond the scope of this Master Servicing Study. However, as noted above, the anticipated rate of build-out will afford sufficient time for the City to complete the required EA studies and identify any capital improvement projects required to accommodate build-out in the whole of the WRC catchment area.

 

Development within Barrhaven South can therefore proceed at the proposed development densities, as the City will undertake the required capacity allocation planning for the WRC trunk sewer.

 

Evaluation of Wastewater Servicing Alternatives:

 

An evaluation of wastewater servicing alternatives was conducted to determine a suitable internal servicing concept. The two servicing alternatives reviewed were:

 

Alternative I:  Implementation of a new waste water system including a treatment plant and collection system.

Alternative II: An extension of the existing wastewater system, including all works necessary to connect to the existing system.

 

The evaluation of alternatives was based, in part, on criteria previously used by the former Region of Ottawa Carleton in the preparation of Master Plans for Water, Wastewater and Transportation. The criteria are comprised of four main categories including Constructability/Functionality, Economy, Caring and Healthy Community, and Natural Environment.  Based upon this evaluation, Alternative II was selected as the preferred solution. The preferred wasterwater servicing plan is shown on Figure SAN-1 in Document 4.

Water Servicing:

 

The major water distribution infrastructure components required to service the Barrhaven Pressure Zone were identified in a previous consultant study (Barrhaven, 2W and 3W Pressure Zones Infrastructure Assessment, Stantec Consulting Ltd., 2002). With respect to major water distribution infrastructure outside of the Barrhaven Pressure Zone, reference is made to the 2002 Stantec study that identified piping requirements to both Barrhaven and the SUC based on anticipated demands. This Master Servicing Study evaluated two water servicing alternatives and  completed hydraulic analyses to confirm the adequacy and reliability of the proposed system to service Barrhaven South.

 

Evaluation of Water Servicing Alternatives

 

To accommodate development within Barrhaven South and surrounding areas, an evaluation of two water supply and distribution alternatives was completed, using the same prescribed criteria as were applied for the wastewater servicing alternatives. In terms of location, all watermains have been located within transportation corridors identified through the Barrhaven South CDP.

 

Alternative I: Implementation of a new water system including a water source, treatment plant and/or distribution system.

Alternative II: An expansion of the existing water distribution system, including new equipment and facilities to increase the system capacity.

Based upon the evaluation, Alternative II was selected as  preferred water supply alternative. The preferred water supply plan is shown on Figure WM-1 in Document 4. 

 

Hydraulic Analyses of Proposed Water Distribution System:

 

Barrhaven South is located adjacent to the existing Barrhaven Pressure Zone (Zone BAR). Based upon current growth projections, hydraulic analyses were completed that confirmed the adequacy and reliability of the proposed water distribution system.

 

Storm Drainage/Stormwater Management

 

Stormwater management criteria and the approach to accommodating the four existing municipal drains/tributaries within the study area were determined through the preparation of the Jock River Reach 1 Subwatershed Study (Stantec, 2007) and the Conceptual Fisheries Compensation Plan (Niblett Environmental Associates, 2007) as summarized previously in this staff report.  The Master Servicing Study made use of these recommendations and SWM design criteria to develop conceptual storm drainage and stormwater management servicing plans for the study area.

 

Evaluation of Stormwater Management Servicing Alternatives

 

Five different stormwater management servicing alternatives were considered and evaluated.  The criteria used to assess the stormwater management alternatives differed from those used to assess the wastewater and water servicing alternatives as a result of different constraints. 


An initial screening of alternatives was based on the following evaluation criteria:Financial; Fish and Aquatic Life; Terrestrial and Vegetation Communities; Social/Community. The five SWM servicing alternatives that were evaluated are summarized as follows:

 

Option #1

·           Single facility with an outlet to the Jock River east of Jockvale Road

·           No allowance for the preservation of any existing municipal drains

·           All storm sewers are tributary to the proposed pond

·           One main trunk inlet to pond

 

Option #2

·           Two facilities located adjacent to the Jock River floodplain: one facility adjacent to Jockvale Road, the second located east of Cedarview Road

·           No allowance for the preservation of any existing municipal drains

·           Multiple trunk storm sewer inlets to ponds

 

Option #3

·           Three facilities

·           Proposed to preserve and outlet facilities to a portion of the existing West Clarke, Todd and Corrigan municipal drains

·           Proposed to rehabilitate for improved fish habitat portions of drains to remain open

·           Multiple trunk storm sewer inlets to ponds

 

Option #4

·           Five ponds

·           Two facilities adjacent to floodplain as per Option #2

·           Two facilities along Todd drain 

·           One facility draining to West Clarke drain south of Cambrian Road

·           Proposed to maintain West Clarke and Todd drains in existing configuration commencing just south of Cambrian Road to the Jock River

 

Option #5

·           Eight ponds

·           Existing four municipal drains to remain as is

·           Multiple storm sewer inlets and multiple ponds, reducing size of trunk sewers

 

The five stormwater management alternatives were evaluated using the criteria noted above using a standard “pair-wise comparison” methodology. Based upon the evaluation of the five alternatives, Option 3 (see Document 4, Figure 6.3) was selected as the preferred alternative as it provided the best overall performance with respect to the chosen criteria. Futher details regarding the evaluation are provided in Document 6.

 

Storm Drainage

 

Following from the selection of the preferred stormwater management alternative, preliminary design was completed for the three SWM facilities, the storm sewer systems tributary to each of the three SWM facilities, and the two rehabilitated municipal drains.

Storm Sewer System Design:

 

The design of the storm trunk sewers was generally established by following the proposed roadway layout and in accordance with City design criteria. The storm servicing network in shown on Figure ST –1 in Document 4.

 

Subsurface investigations of the study area have identified soil conditions (compressible silty clays) which limit the extent to which the site may be raised: a maximum fill depth of 1.5 meters above existing grade has been assumed for preliminary design. Given the low lying areas in the northern portion of the study area and the grade raise restrictions noted above, much of the storm sewer system has minimal cover and a portion of the system will be subject to permanent standing water. These conditions will preclude the use of standard depth basements over a significant portion of the study area. 

 

In consideration of this, alternatives to basement connections to the sewer system were considered, including a foundation drain collector (FDC) system and sump pumps. Use of an FDC system (a ‘third pipe’system that drains only basement connections) was eliminated as this represented approximately one third additional infrastructure to maintain and did not eliminate the problem of standing water in the storm sewer system that would still be required for surface drainage.

 

The use of sump pumps was also proposed but this option was not considered an acceptable design practice for greenfield development areas. Accordingly, through the Community Design Plan process, an effort was made to maximize land uses in the affected area that will not require basements, thus being unaffected by the unavoidably shallow storm sewers. In response, Greenbank Road was relocated further west, and school sites and commercial lands were introduced to reduce the affected area. Notwithstanding this effort, there remains a significant portion of the site slated for residential development that may require slab-on-grade construction and/or non-standard basement depths. The area affected by grade raise constraints and/or shallow storm sewers is shown on Figure GP-1 in Document 4.

 

Preliminary design completed for the Master Servicing Study has assumed a maximum grade raise of 1.5 meters, however, further detailed geotechnical investigations will be required during detailed design to confirm the permissible grade raise. and to determine the extent to which practices such as pre-loading or surcharging will be required to safely accommodate the proposed grade raise. Such measures will require additional time to prepare the site for servicing.

 

Operation and Maintenance Considerations for Standing Water in Storm Sewers

 

As discussed previously, site constraints present storm servicing challenges. The north half of the site is very flat; the Jock River corridor has no defined valley offering no opportunity to deepen storm outlets; and there are fill restrictions (1.5m max. ) over more than half of the site. Based upon preliminary design, this combination of challenges has resulted in a storm system with over three kilometers of pipe with permanent standing water and large areas with minimal (frost) cover on the pipes and/or elevated hydraulic grade lines that will not allow the use of standard basement depths.

 

The permanent standing water will result in signficantly increased costs to the City to own, operate and maintain the affected sewers due to increased sedimentation. As such, during detailed design, an appropriate solution to address increased sedimentation resulting from the submerged condtion must be developed. Consideration will be given to a range of options that provide for drawing down the affected sewers and sediment forebays to create free flow conditions and self-cleansing velocities at the start of the next rainfall event.  Staff of the Wastewater and Drainage Services Division of the Public Works and Services Department were consulted throughout the preliminary design of the storm drainage system and have concurred with the above approach to determine the most appropriate solution at the detailed design stage.

 

Rehabilitated Tributaries (Municipal Drains)

 

As recommended through the Jock Reach 1 Subwatershed Study and further detailed in the Conceptual Fish Habitat Compensation Plan, the East Clarke Drain and the majority of the Corrigan tributary will be enclosed.  The West Clarke and Todd Drains will be partially enclosed, relocated and rehabilitated to improve fish habitat.  The rehabilitated drains/tributaries will also serve as the conveyance channel for flows discharging from the proposed stormwater management facilities. 

 

Preliminary design of the rehabilitated drains has been completed including the determination of plan forms, meander belt widths, cross-sectional dimensions, and longitudinal profiles.  The cross-sections have been designed to convey 100-year peak flows from the SWM facilities.  The low flow channels have been designed applying natural channel design principles with a sequence of riffles and pools to enhance fish habitat. 

 

Next Steps

 

The Barrhaven South Master Servicing Study will be finalized after City Council approves the recommended projects to service the development area.  Notices of Completion will be published for the Jock River Reach 1 Subwatershed Study and Barrhaven South Master Servicing Study notifying the public of the availability of the reports and the 30-day public review period.  The Notice of Completion for the Master Servicing Study will identify the following preferred projects:

 

·           Wastewater collection system  (Schedule B)

·           Water distribution system (Schedule B)

·           Enclosure/partial enclosure of four watercourses – East Clarke Drain, West Clarke Drain, Todd Drain and Corrigan Drain (Schedule B)

·           Construction of three stormwater detention facilities and associated storm drainage collection systems, including:

o          Corrigan SWM Pond and associated storm sewers (Schedule B)

o          Todd SWM Pond and associated storm sewers (Schedule B)

o          Clarke SWM Pond and associated storm sewers (Schedule B)

 

 

ENVIRONMENTAL IMPLICATIONS

 

Subwatershed planning is an integrated, ecosystem approach to land use planning based on the natural boundaries of a drainage area.  The Jock River Reach 1 Subwatershed Plan provides an environmental road map for City staff, developers, agencies, landowners and stakeholders to properly plan development in the subwatershed that aims at protecting and improving the long-term health and viability of its natural resources.  The environmental analysis conducted through the subwatershed study has informed and guided the envelope of built form, design layout and development guidelines for Barrhaven South Community Design Plan that is aimed at meeting the City’s goal of sustainable development.

 

The Barrhaven South Conceptual Fish Habitat Compensation Plan was developed by applying an integrated planning approach as recommended in the Lower Rideau Watershed Strategy.  Examining and understanding the fisheries resources within the tributaries and Jock River has enabled a proactive, holistic approach to be undertaken that recognizes development and servicing requirements while ensuring a net gain in fisheries habitat and productive capacity.  Although loss of fish habitat through tributary enclosures will occur through the development of Barrhaven South, the opportunity to improve the remaining tributaries and creation of new spawning habitat will result in twice as much improved/created fish habitat area as is anticipated to be lost. 

 

The subwatershed study has informed the identification and planning of infrastructure in Barrhaven South to ensure there is no conflict with the infrastructure servicing and environmental recommendations.  The recommended infrastructure projects have been identified through a Class Environmental Assessment process.  As such, the environmental conditions, impact assessment, mitigation and monitoring measures have been accounted for in determining the preferred alternatives. 

 

 

RURAL IMPLICATIONS

 

The subwatershed study focuses on the environmental and conceptual stormwater management requirements associated with future development lands.  There is a small portion of the study area in the rural area as well as floodplain lands under agricultural operation in the urban area.  There are six recommendations pertaining to rural/ agricultural lands:

 

·           Promote agricultural Best Management Practices (BMPs) through the Lower Rideau Watershed Strategy implementation committee.

·           Removal of municipal drains in Barrhaven South to be abandoned prior to development.  Consent of all signatories on original agreement required.

·           Provide a recreational trail along both sides of the Jock River - pathway to be implemented as part of the development approval process; in non-development area, investigate opportunities for pathway, where feasible, contingent on landowner consent.

·           Country lot estate development north of Fallowfield Road - use of lot and conveyance measures to be maximized to achieve SWM design criteria prior to consideration of end-of-pipe facilities.

·           For the development north of the river, two stormwater management facilities are conceptually identified on lands partially within the floodplain.  The lands to accommodate the facility would have to be acquired from the landowner.

·           Further environmental investigation of woodlot W4 subject to permission by the landowner.

 

All of these recommendations will require further action and consultation with the affected landowners.  Implementation of the recommendations is subject to the landowner agreement.

 

 

CONSULTATION

 

A comprehensive public consultation program was developed to integrate and facilitate the CDP and technical studies process meeting the requirements of both the Planning Act and Environmental Assessment Act.  A total of four (4) formal public open houses for this project were held at the Walter Baker Centre in the Barrhaven community on:

 

·           April 14, 2005 – Introduction to the Study / Phase 1 of EA

·           July 20, 2005 – Presentation of Alternative Solutions / Phase 2 of EA

·           January 26, 2006 – Evaluation of Alternative Solutions / Phase 2 of EA

·           March 29, 2006 – Selection of Preferred Solution / Phase 2 of EA

 

These public events involved opportunities for the public to review the analysis and work to date, and to ask questions to City staff and the full consulting team.  Notices for all public meetings addressed both the planning process, as well as all requirements of the environmental assessment (EA) process.  In addition to the Open Houses that specifically focused on the Barrhaven South CDP and the technical studies, the project team also participated in general open houses hosted by the Ward Councillor in October 2005 and April 2006.

 

The Subwatershed and Master Servicing Studies solicited input from various City divisions within Planning, Transit and Environment and Public Works and Services Departments.  In addition to the involvement of City staff, many government agencies and approval authorities were involved in the planning and technical study process.  A formal Technical Advisory Committee (TAC) was established for the CDP process.  In addition, a technical sub-committee was formed for both the subwatershed and master servicing study to discuss in detail the issues relevant to these technical studies.  For the subwatershed study, the sub-committee was represented by staff from the City, Rideau Valley Conservation Authority (RVCA), Department of Fisheries and Oceans (DFO), Ministry of Environment (MOE) and the Ministry of Natural Resources (MNR).  These provincial and federal agencies were also contacted individually for specific advice and input regarding relevant issues and approvals as they arose.  Sub-committee members were provided the interim and draft reports for review and input.

 

A total of 8 TAC and sub-committee meetings were held over the course of the project.  Verbal and/or written comments were received from MOE, MNR, RVCA, DFO, and City staff at major milestones of the study, including review of draft and final reports.  All comments received from City staff and government agencies have been addressed and incorporated into the final documents. 

For the subwatershed study, individual meetings and/or circulation of the interim and final draft reports were provided to the City’s Ottawa Forest and Greenspace Advisory Committee, the Friends of the Jock River and major developers north of the Jock River.  Comments were received from Friends of the Jock River and OFGAC on the interim report and draft final report respectively.  A response to the comments received was provided to these two public groups and relevant comments incorporated into the final report.

 

Two meetings occurred with the major developers north of the Jock River on March 3, 2006 and January 19, 2007.  The purpose of the first meeting was to present the conceptual stormwater management options for north of the Jock River to service the O’Keefe and Foster Ditch drainage areas.  The developers in attendance concurred on Option 2 illustrating a three-pond scenario to service the Foster and O’Keefe drainage areas.  The purpose of the January 19, 2007 meeting was to present the preferred management plan and implementation strategy for north of the Jock River.  Issues raised in the meeting were related to development setbacks, Development Charges by-law amendment, and catchment area boundary for studies on the Foster Ditch.  These issues were resolved through text modifications and commitment to have further discussions during the DC by-law amendment process.

 

Overall the studies benefited from a broad range of technical advice and direction.

 

 

FINANCIAL IMPLICATIONS

 

The infrastructure servicing projects as defined as local servicing in the Development Charge By-law 2004-298, as recommended in the Barrhaven South Master Servicing Study will be designed and constructed by developers.  The Area-Specific Stormwater Development Charge By-law 2004-304 entitled Nepean South Urban Centre Stormwater Facilities will have to be amended to reflect the stormwater management solution identified north of the Jock River in the subwatershed study and the required stormwater management facilities and associated storm sewers identified in the Master Servicing Study for Barrhaven South.  The main development charge by-law 2004-298 will be amended in the next five year review, as scheduled in 2009, for all remaining development charge eligible works.

 

As discussed previously, site constraints will result in permanent standing water in a significant portion of the storm sewer system. This result has the potential to significantly increase long-term maintenance and operation costs through the need for regular pumping to draw down the sewers and/or other measures to manage the increased potential for sedimentation in the pipes.

 

The fish habitat compensation project on City lands identified in the Barrhaven South CFCP will be the financial responsibility of the developers including land costs.  Any financial requirements associated with environmental recommendations carried out by the City will be reflected in future program budgets, subject to Council approval.  Securement of the two significant woodlands in private ownership is reflected in the Long-Range Financial Plan 3.

 

 

SUPPORTING DOCUMENTATION

 

Document 1      Study Area Location Map

Document 2      Jock River Reach 1 Subwatershed Study and Conceptual Fish Habitat Compensation Plan (distributed under separate cover)

Document 3      Environmental Constraints and Opportunities Map and Key Findings

Document 4      Master Servicing Projects: Figures SAN-1, WM-1, 6.3, ST-1, and GP-1

Document 5      Conceptual Stormwater Management Option 2, North of the Jock River - Figure 6.4.2

Document 6      Master Servicing Study: Evaluation of Stormwater Management Alternatives

 

 

DISPOSITION

 

1.   Planning, Transit and Environment will finalize the Barrhaven South Master Servicing Study Class Environmental Assessment Report and file the Notices of Completion to initiate the 30-day public review period of the Master Servicing Study and Subwatershed Study. Once the Class EAs are approved under the Environmental Assessment Act, projects identified in the Master Servicing Study may proceed to detailed design and final City approval through delegated authority.

 

2.   Planning, Transit and Environment will make the Jock River Reach 1 Subwatershed Study and the Barrhaven South Master Servicing Study available through the main branch of the Ottawa library, Barrhaven library branch and the Ben Franklin Client Service Centre.

 

3.   Legal Services to bring forward to City Council the Barrhaven South draft Official Plan Amendment implementing by-law.

 

4.   Public Works and Services to bring forward the abandonment report for municipal drains situated in the Barrhaven South development area to City Council for approval.

 

5.      Planning, Transit and Environment will coordinate the detailed design, approval and construction of the new fish habitat area on City lands.

 

6.      Planning, Transit and Environment will revise the Area-Specific Stormwater Development Charge By-law 2004-304, for north and south of the Jock River and bring forward for Council approval.

 

 

STUDY AREA LOCATION MAP                                                                          DOCUMENT 1

 

ENVIRONMENTAL CONSTRAINTS AND OPPORTUNITIES

MAP AND KEY FINDINGS                                                                                   DOCUMENT 3

 

Tributaries:

·           North of the Jock River, the main tributaries are O’Keefe Drain, Foster Ditch and Fraser Clarke Drain.

·           South of the Jock River, the main tributaries are the West Clarke Drain, East Clarke Drain, Todd Drain and Corrigan tributary.

·           O’Keefe, Fraser-Clarke, West Clarke, East Clarke and Todd tributaries are municipal drains.

·           All tributaries to the Jock River support fisheries and are considered fish habitat.

·           The tributaries provide only a highly seasonal and marginal fish habitat for a handful of warm water tolerant fish species.

·           The tributaries can run dry or low after high spring water levels.

·           Tributaries have been largely modified by channel straightening with little or no riparian vegetation.

·           As per the Lower Rideau Watershed Strategy, if an integrated stormwater management approach is undertaken consideration of partial or full enclosure of the drains south of the Jock River can be considered if DFO requirements are fulfilled.

·           Opportunity exists to enhance low flows in the tributaries and Jock River through stormwater management.

 

Terrestrial Resources:

·           A total of 28 woodlands exist in the subwatershed.

·           North of the Jock River, Woodlot W44 (UNA #50), Woodlot W43 (UNA#60) and Woodlot W50 (UNA #183) are considered significant woodlands.

·           South of the Jock River, Woodlots W1 and W2 (UNA #57), Woodlot W4 (rural), Woodlot W7 (UNA #49) and W10 (UNA #58) are considered significant woodlands.

·           Management plans should be prepared to maintain environmental integrity of the woodlands over the long-term.

·           There is very low representation of wetlands within Reach 1.

·           A total of 88 species of birds has been recorded as breeding in the area including forest, edge and wetland species. 

·           Forest interior habitat is contained within Woodlands W1 and W2 (UNA #57).

·           A total of 10 species of amphibians, 3 species of reptiles and 18 species of mammals have been recorded.

·           Significant species reported or observed include one federal (butternut), one provincial (greater redhorse fish species) and fourteen regionally rare species.

·           Terrestrial corridor function was identified along the Jock River.

·           Terrestrial corridor potential was identified along the O’Keefe Drain connecting Stony Swamp and the Jock River.

 

Jock River:

·           Jock River is highly productive fisheries resource that contains healthy populations of naturally reproducing game fish such as muskellunge. 

·           A number of important and/or critical fish habitat areas within the main stem of the Jock River have been identified within Reach 1.

·           There is limited riparian vegetation along the river corridor.

·           Groundwater flow is generally towards the river that is identified as a discharge area.

·           Recharge area function associated with sand and gravel resource areas, south of Cambrian Road, was identified.

·           Low summer flows in the Jock River.

·           Jock River water quality is highly impaired and does not meet provincial water quality criteria.

·           The Jock River is classified as a Policy 2 watercourse for phosphorus, which requires a net reduction in phosphorus loadings to the river.

·           The extent of the regulatory floodplain through Reach 1 is defined by the 100-year flood as per mapping recently updated by the Rideau Valley Conservation Authority in November of 2005

·           Through the fluvial geomorphoric investigation, the meander belt width was determined for the Jock River corridor representing the maximum lateral extent of the channel voer time.  Meander belt is considered a hazard constraint that needs to be considered in establishing development setbacks from the river.

·           Further erosion and migration analysis is recommended for Reaches 1 and 2 of the Jock River to confirm meander belt width.

 

MASTER SERVICING PROJECTS:  FIGURES SAN-1, WM-1,

6.3, ST-1 AND GP-1                                                                                                 DOCUMENT 4

 





CONCEPTUAL STORMWATER MAGEMENT OPTION 2,

NORTH OF THE JOCK RIVER – FIGURE 6.4.2                                                DOCUMENT 5

 

MASTER SERVICING STUDY:  EVALUATION OF

STORMWATER MANAGEMENT ALTERNATIVES                                       DOCUMENT 6

 

Financial:

Capital costs were estimated based on the following criteria:

·           Ponds have been sized and costed assuming quality control only

·           Storm sewers have been sized using the 5-year rational method.

 

Based on the above criteria, the total estimated capital cost for each alternative was determined to be:

·           Option 1 - $54 million

·           Option 2 - $41 million

·           Option 3 - $39 million

·           Option 4 - $43 million

·           Option 5 - $42 million

 

Option 1 was most expensive due to large deep storm trunks sewers. Option 5 was the next most expensive due to the number of ponds and associated land costs. Option 3 was least expensive, using centrally located ponds. Option 4 was similar to Option 3.

 

Maintenance costs:

Maintenance costs were assessed using the suggested practices in the Stormwater Management Planning and Design manual, Ministry of the Environment (March 2003).

 

·           Due to the site having a large, low-lying area and grade raise restrictions over this same area, all options considered would result in a similar amount of submerged pipe. Maintenance costs for the submerged systems were similar for all alternatives.

·           Option 1 was more economical with respect to maintenance costs; Option 5 less economical.

 

Fish and Aquatic Life

i) Low Flow Augmentation to Tributaries via SWM:

·           Use of storm ponds to augment flow in rehabilitated tributaries to support future fish habitat

·           Options 1 and 2 provide no opportunity (no drains remain open).

·           Options 2 and 3 provide the greatest opportunities as they concentrate more surface water to two tributaries/drains.

 

ii) Enhancement of Existing Aquatic Habitat:

·           Options 1 and 2 provide no opportunity.

·           Option 3 provides the best opportunity to increase diversity of fish community in two tributaries providing improved slopes and augmented flow from storm ponds. 

·           Option 4: longer flat tributaries with 5 proposed ponds provides less water at the tributary head than Option 3.

·           Option 5: maintains existing conditions with ditches and associated (degraded) habitat as it exists today

 

iii) Preservation and Enhancement of Sensitive Habitat:

Options 3 and 4 augment flow to the muskie spawning habitat identified adjacent to the Jock River, also providing the opportunity to enhance these areas. Option 1 provides no augmented flow to these areas, while Option 2 provides limited opportunity.

 

iv) Maintain Existing Baseflow Contribution from Woodlot (UNA #57):

·           Options 1 and 2 do little to maintain base flow

·           Option 5 most closely represents existing conditions

·           Option 4 with more ponds and greater ditch lengths scores slightly higher than Option 3

 

Terrestrial Vegetation and Communities:

i) Preservation of Urban Natural areas

All options provide the same opportunity

 

ii) Preservation of Riparian Vegetation

Option 1 provides the least opportunity, while Option 5 provides the most. Options 2, 3, and 4 provide increasingly better opportunities, respectively.

 

iii)Preservation of landscape features

Option 1 provides the least opportunity, while Option 5 provides the best. Options 2, 3, and 4 provide increasingly better opportunities respectively.

 

Social/Community:

 

i) Maintain existing recreation activities:

Existing recreation activities are limited to the river corridor. Based on this, Option 3 with the fewest ponds proposed adjacent to the river provides the least impact. Options 1 and 5 have the greatest impact. Options 2 and 4 have similar impacts.

 

ii) Integrate with Green Open Space/Park System:

·           With no ponds within the community Option 1 and 2 provide limited opportunity

·           Option 5 has too many ponds; roadway crossings and pedestrian crossing will be a constraint

·           Option 3 and 4 provide the best opportunities

 

iii) Integrated/Links with pedestrian network:

·           With no ponds integrated in the community, Options 1 and 2 provide limited opportunity

·           Option 5 has numerous many ponds; roadway and pedestrian crossings would be a constraint

·           Options 3 and 4 provide the best opportunities.