1.            PinEcrest CreeK/Westboro Stormwater Management Retrofit Study

 

                ÉTUDE DE MODERNISATION DE LA GESTION DES EAUX PLUVIALES DU RUISSEAU PINECREST/WESTBORO

 

 

 

COMMITTEE RECOMMENDATIONS

 

That Council:

 

1.                  Approve the preferred Pinecrest Creek/Westboro Stormwater Management Retrofit Plan as described herein and listed as Document 14; and

 

2.                  Approve the filing of the Pinecrest Creek/Westboro Stormwater Management Retrofit Study for the 30-day public review period in accordance with the Ontario Environmental Assessment Act.

 

RECOMMANDATIONS DU COMITÉ

 

Que le Conseil :

 

1.                  approuve le Plan privilégié de modernisation de la gestion des eaux pluviales du ruisseau Pinecrest/Westboro comme il est décrit dans la présente et soumis sous pli séparé;

 

2.         approuve le dépôt de l’Étude de modernisation de la gestion des eaux pluviales du ruisseau Pinecrest/Westboro pour la période d’examen public de 30 jours conformément à la Loi sur les évaluations environnementales de l’Ontario

 

 

 

 

 

 

DOCUMENTATION :

 

 

1.                  Deputy City Manager, Infrastructure Services and Community Sustainability report dated 20 September 2011 (ACS2011-ICS-PGM-0114);

 

 

 

Report to/Rapport au :

 

Environment Committee

Comité de l'environnement

 

and Council / et au Conseil

 

20 September 2011 / le 20 septembre 2011

 

Submitted by/Soumis par : Nancy Schepers, Deputy City Manager, Directrice municipale adjointe, Infrastructure Services and Community Sustainability, Services d'infrastructure et Viabilité des collectivités

 

Contact Person/Personne-ressource : Richard Kilstrom, Manager/Gestionnaire, Policy Development and Urban Design/Élaboration de la politique et conception urbaine, Planning and Growth Management/Urbanisme et Gestion de la croissance Élaboration de la politique et conception urbaine

(613) 580-2424 x22653, Richard.Kilstrom@ottawa.ca

 

Bay/Baie (7), College/Collège (8), Knoxdale‑Merivale (9), Kitchissippi (15)

Ref N°: ACS2011-ICS-PGM-0114

 

 

SUBJECT:

PinEcrest CreeK/Westboro Stormwater Management Retrofit Study

 

 

OBJET :

ÉTUDE DE MODERNISATION DE LA GESTION DES EAUX PLUVIALES DU RUISSEAU PINECREST/WESTBORO

 

 

 

REPORT RECOMMENDATIONS

 

That Environment Committee recommend Council:

 

1.                  Approve the preferred Pinecrest Creek/Westboro Stormwater Management Retrofit Plan as described herein and listed as Document 14; and

 

2.                  Approve the filing of the Pinecrest Creek/Westboro Stormwater Management Retrofit Study for the 30-day public review period in accordance with the Ontario Environmental Assessment Act.

 

RECOMMANDATIONS DU RAPPORT

 

Que le Comité de l’environnement recommande au Conseil :

 

1.                  d’approuver le Plan privilégié de modernisation de la gestion des eaux pluviales du ruisseau Pinecrest/Westboro comme il est décrit dans la présente et soumis sous pli séparé;

 

2.                  d’approuver le dépôt de l’Étude de modernisation de la gestion des eaux pluviales du ruisseau Pinecrest/Westboro pour la période d’examen public de 30 jours conformément à la Loi sur les évaluations environnementales de l’Ontario.

 

 

Executive Summary

 

Assumptions and Analysis:

 

Stormwater management (SWM) retrofit refers to the insertion of various measures into established, older communities that were originally built without the infrastructure needed to mitigate the impacts of uncontrolled runoff. Unlike greenfield development, where SWM measures are incorporated as a matter of course, the challenge of SWM retrofit is to identify effective measures that can be implemented after the fact – when there is limited land available to implement conventional SWM facilities.

 

This Study was undertaken to develop a SWM retrofit plan for the Pinecrest Creek subwatershed and adjacent Westboro area, both of which drain to the Ottawa River upstream of Westboro beach. The study area, shown in Document 1, has little or no SWM controls in place as the great majority of the area was built out well before current SWM requirements were in place. The consequences of this historical lack of stormwater management include:

 

 

All of these concerns are directly traceable to the highly urbanized nature of the study area and its lack of stormwater management.

 

Beyond the existing impacts of uncontrolled stormwater runoff, infill and redevelopment is also occurring in the study area, the cumulative impacts of which will further contribute to the problems noted above.

 

This Study is one of 17 Ottawa River Action Plan (ORAP) projects, as adopted by City Council on February 24, 2010: http://ottawa.ca/calendar/ottawa/citycouncil/pec/2010/02-09/13%20-%20ACS2010-ICS-ESD-0007%20-%20FINAL%20-%20ORAP.htm. Two key objectives of ORAP are to: optimize recreational use and economic development of the river, with a focus on reducing beach closures; and to maintain a healthy aquatic ecosystem, with a focus on addressing challenges presented by existing infrastructure. To achieve these objectives, ORAP identified that the impacts of uncontrolled stormwater runoff must be addressed.

 

The Retrofit Study is a first step toward addressing the impacts of uncontrolled stormwater on the Ottawa River and its many tributaries. It identifies a long-term plan composed of a range of programs, capital projects and outreach efforts aimed at reversing or partially reversing the historical impacts of development on the Creek and local reach of the Ottawa River. The Study has also served as a pilot for the future preparation of similar retrofit plans for older areas of the City that developed with little or no stormwater management.  These additional retrofit studies are also identified in ORAP.

 

With respect to Westboro Beach, it is important to note that “wet weather,” while a key contributor to the high number of beach closures, is not the only factor. Other “dry weather” factors, unrelated to wet weather, may also warrant further consideration. This Study addresses only the wet weather aspects of beach closures.

 

The overall purpose of completing the Retrofit Study was to recommend what combination of retrofit measures to apply in the study area that would provide the best solution considering a number of economic, environmental and social factors.

 

To develop the Retrofit Plan, the following key steps were undertaken:

 

i)        Setting the Stage: Existing Conditions and SWM Retrofit Potential;

ii)      SWM Retrofit: Selection of the Preferred Scenario;

iii)    Public Consultation and Communications; and

iv)    Preparation of an Implementation and Monitoring Plan.

 

These steps were also completed to ensure consistency with the requirements of the Municipal Class Environmental Assessment (MCEA) given the anticipated identification of various capital projects. The study was conducted as a Master Plan per the MCEA process. Existing conditions were described, problems, opportunities and a range of solutions were identified, and the various solutions evaluated to arrive at a preferred approach, the recommended Retrofit Plan. Public consultation requirements of the MCEA were also fulfilled.

 

As a Master Plan, the Retrofit Study was completed at a broad level of assessment. More detailed investigations will be required in order to fulfil the MCEA requirements for Schedule B and C projects identified within the recommended Retrofit Plan. As required by the MCEA process, the Retrofit Plan will be reviewed every five years.

 

Subject to City Council adoption of the recommended Retrofit Plan, it will be posted for a 30‑day public review period as required by the MCEA.

 

The preferred Retrofit Plan is composed of:

 

 

A 50 year time frame has been suggested to complete implementation of the preferred Retrofit Plan. This will allow for retrofits within the rights-of-way and on City-owned properties to be completed “opportunistically,” i.e., when roadways, City buildings and parking lots come to the end of their life cycle. This time frame also recognizes the considerable challenge of engaging sufficient participation from residential and other private property owners. The 50 year life cycle cost of the preferred Retrofit Plan is $43M.

 

Financial Implications:

 

The recommended Retrofit Plan, if adopted, will provide the basis for annual budget requests to support the long-term implementation of the various components of the Plan (initial pilot projects, capital projects, education/public outreach, monitoring of overall effectiveness, on-going maintenance of implemented projects, etc.).

 

For the 2012 budget process, funding to begin implementation of the Retrofit Plan has been included for consideration in the draft rate budget in the amounts of $2M for 2012, $2M for 2013 and $9M for 2014. Earlier estimates of projected annual costs for stormwater retrofit were also accounted for in the Cost, Rate and Revenue Study (ACS2010-ICS-ESD-0002).

 

Public Consultation/Input:

 

Public consultation and communication efforts undertaken for the study included the following:

 

Technical Advisory Committee: The Technical Advisory Committee (TAC) was comprised of City staff from a variety of departments, and representatives from the National Capital Commission (NCC), Ministry of the Environment, Rideau Valley Conservation Authority and Algonquin College. The TAC met three times during the study - on December 3, 2009, June 17, 2010 and November 30, 2010 and provided advice and guidance to the study team on a range of issues.

 

Public Advisory Committee: The Public Advisory Committee (PAC) was comprised of five residents and met four times during the study – on October 6, 2009, January 13, 2010, June 17, 2010 and November 30, 2010. The PAC provided valuable comments on how best to reach people in the study area, reviewed interim reports, and constructively critiqued the study.

 

Open Houses: Open Houses were held on December 3, 2009 (attended by 14 people) and December 1, 2010 (attended by eight people).

 

Advisory Committees of Council: Presentations were made to the Environmental Advisory Committee on September 9, 2010, and May 12, 2011, and the Ottawa Forest and Green Space Advisory Committee on July 26, 2010 and July 25, 2011.

 

Participation in other City consultation events: Staff provided information about the study at Ottawa River Action Plan Open Houses held November 23, 26, and 30 and December 1, 2009.

 

Other Consultations: On November 14, 2009, a presentation was made to the annual Community Associations Forum on Environmental Sustainability, a gathering of city-wide community associations. On April 29, 2010, a presentation was made to the Westboro Beach Community Association at its Annual General Meeting. Finally, on June 17, 2010, a meeting was held with two local teachers to seek their advice regarding opportunities for potential future collaboration relating to retrofitting SWM measures. This included possible tie-ins to the curriculum, involving students in monitoring activities and liaising with School Boards on potential SWM projects such as disconnections of downspouts or the construction of rain gardens.

 

Newspaper Advertisements: Advertisements for the Open Houses (including the Notice of Study Commencement) were placed in local and daily newspapers.

 

Flyers: Flyers were developed in advance of the Open Houses to provide basic information about the study and promote the Open Houses. These were e-mailed to those on the study mailing list, which included individuals, environmental groups and community associations. Prior to the second Open House, flyers were posted at local community centres and other venues in the study area.

 

E-Newsletters: E-newsletters were developed to introduce the study and provide progress updates. These were sent to individuals, environmental groups, community associations and ward Councillors in July 2010, October 2010 and November 2010.

 

Website: A website was created to provide access to more detailed information about the study:

http://ottawa.ca/residents/public_consult/pinecrest_westboro/index_en.html

 

Comments received from the public, TAC and PAC were generally supportive of the purpose and recommendations of the study.

 

 

RÉSUMÉ

 

Hypothèses et analyse :

 

La modernisation de la gestion des eaux pluviales (GEP) renvoie à l’intégration de diverses mesures au sein de collectivités anciennes et établies qui étaient au départ construites sans l’infrastructure nécessaire pour réduire les répercussions des eaux de ruissellement non contrôlées. Contrairement à l’aménagement des zones vertes, où les mesures de GEP sont pratiques courantes, la modernisation de la GEP pose le défi de cerner des mesures efficaces qui peuvent être mises en œuvre après l’aménagement des terres – et lorsque les terres vierges disponibles sont insuffisantes pour prévoir des installations de GEP traditionnelles.

 

Cette étude a été menée dans le but de concevoir un plan de modernisation de la GEP pour le sous-bassin hydrographique du ruisseau Pinecrest et le secteur adjacent de Westboro, les deux se déversant dans la rivière des Outaouais en amont de la plage de Westboro. Le secteur à l’étude, illustré dans le Document 1, possède peu d’installations de contrôle de la GEP, voire n’en possède aucune, étant donné qu’il a été construit, dans sa grande majorité, bien avant que les exigences actuelles en matière de GEP soient introduites. Les conséquences de ce manque historique de GEP se sont révélées être :

 

 

Toutes ces préoccupations sont directement liées à la nature fortement urbanisée du secteur à l’étude et à son manque de gestion des eaux pluviales.

 

En plus des conséquences connues des eaux de ruissellement non contrôlées, l’aménagement sur terrain intercalaire et le réaménagement sont aussi à blâmer dans ce secteur. Leurs impacts cumulatifs ne feront qu’accentuer les problèmes susmentionnés.

 

Cette étude est l’un des 17 projets à court terme du Plan d’action de la Ville visant la rivière des Outaouais (PARO), tels que les a adoptés le Conseil municipal le 24 février 2010 : http://ottawa.ca/calendar/ottawa/citycouncil/pec/2010/02-09/13%20-%20ACS2010-ICS-ESD-0007%20-%20FINAL%20-%20ORAP.htm. Les deux principaux objectifs du PARO sont, d’une part, d’optimiser le développement économique de la rivière et son utilisation à des fins récréatives, notamment par la diminution des fermetures de plages, et, d’autre part, de maintenir un écosystème aquatique sain, en se consacrant surtout aux difficultés que posent les infrastructures existantes. Pour atteindre ces objectifs, le PARO a identifié les conséquences néfastes des eaux de ruissellement non contrôlées auxquelles on doit remédier.

 

L’Étude de modernisation est un premier pas vers la remédiation de ces conséquences sur la rivière des Outaouais et ses nombreux affluents. Elle définit un plan à long terme composé de toute une gamme de programmes, de projets d’immobilisations et d’efforts de rayonnement qui visent tous à renverser, en tout ou en partie, les répercussions historiques de l’aménagement dans le ruisseau et la rivière des Outaouais dans lequel il se déverse. L’étude a également servi de pilote à la préparation future de plans de rénovation semblables pour les vieilles zones aménagées de la Ville ayant peu d’installations de gestion des eaux pluviales voire même aucune. Ces études supplémentaires de modernisation sont elles aussi définies dans le PARO.

 

En ce qui concerne la plage de Westboro, il importe de noter que le « temps pluvieux », bien qu’il soit un facteur contributif clé de la fréquence élevée des fermetures de la plage, n’est pas le seul. D’autres facteurs en « temps sec », indépendants du temps pluvieux, peuvent aussi être pris en compte. Or, la présente étude aborde uniquement les aspects du temps pluvieux des fermetures de plages.

 

L’Étude de modernisation avait pour objectif global de recommander quelles mesures pouvaient ensemble s’appliquer au secteur à l’étude et offrir la meilleure solution possible étant donné les facteurs économiques, environnementaux et sociaux existants.

 

Pour concevoir le Plan de modernisation, les étapes clés suivantes ont été prises :

i)        Mise en contexte : conditions existantes et potentiel de modernisation de la GEP;

ii)      Modernisation de la GEP : Sélection du scénario privilégié;

iii)    Consultation et communication auprès du public;

iv)    Préparation d’un plan de mise en œuvre et de contrôle.

 

Ces mesures visaient également à assurer la conformité du plan aux exigences de l’Évaluation environnementale municipale de portée générale (EEPG) à la lumière de la détermination prévue de divers projets d’immobilisations. L’étude a pris la forme d’un plan directeur, mené selon le processus de l’EEPG. Les conditions existantes y ont été décrites, les problèmes, possibilités et solutions diverses y ont été identifiés, et les solutions ainsi identifiées ont fait l’objet d’une évaluation pour en arriver à l’approche jugée la meilleure : le Plan de modernisation recommandé (dit privilégié). Les exigences en matière de consultation publique de l’EEPG ont également été comblées.

 

En tant que plan directeur, l’Étude de modernisation a été conclue à un niveau général d’évaluation. Des enquêtes plus approfondies devront être menées pour remplir les exigences de l’EEPG vis-à-vis des projets des Annexes B et C définis dans le Plan de modernisation privilégié. Conformément au processus de l’EEPG, le Plan de modernisation sera revu tous les cinq ans.

 

Sous réserve de l’adoption du plan recommandé par le Conseil municipal, le plan sera affiché aux fins d’examen public pendant une période de 30 jours tel que l’exige l’EEPG.

 

Le Plan de modernisation privilégié comprend ce qui suit :

 

 

On a suggéré un délai de 50 ans pour la mise en œuvre complète du Plan de modernisation privilégié. Ce délai permettra d’entreprendre la modernisation des zones d’emprise et des propriétés gérées par la Ville de manière « opportuniste », c’est-à-dire quand les routes, les bâtiments municipaux et les terrains de stationnements arriveront à la fin de leur cycle de vie. En outre, ce délai reconnaît le défi considérable que pose la tâche d’obtenir une participation suffisante de la part des propriétaires résidentiels et d’autres propriétés privées. Le cycle de vie de 50 ans du Plan de modernisation privilégié s’élève au coût de 43 M$.

 

 

Implications financières :

 

Ce rapport n’est lié à aucune implication financière directe. Le Plan de modernisation recommandé, s’il est adopté, fournira la base des demandes d’allocation du budget annuel pour appuyer la mise en œuvre à long terme des diverses composantes du plan (premiers projets pilotes, projets d’immobilisations, activités de rayonnement/éducation auprès du public, contrôle de l’efficacité d’ensemble, maintien continu des projets mis en œuvre, etc.).

 

Dans le cadre du processus budgétaire de 2012, le financement prévu pour la mise en œuvre du Plan de modernisation a été ajouté à des fins d’examen au budget préliminaire des redevances aux montants de 2 M$ pour 2012, 2 M$ pour 2013 et 9 M$ pour 2014. Des prévisions antérieures sur les coûts annuels de modernisation de la gestion des eaux pluviales ont également été prises en compte dans l’Étude des coûts, des revenus et des redevances : http://ottawa.ca/calendar/ottawa/citycouncil/pec/2010/04-13/9%20-%20ACS2010-ICS-ESD-0002%20-%20Rate%20Structure.htm.

 

Consultation/Rétroaction publique :

 

Les efforts de consultation et de communication déployés auprès du public dans le cadre de cette étude comprenaient les suivants :

 

Comité consultatif technique : Le Comité consultatif technique (CCT) se composait de membres du personnel municipal de plusieurs départements et de représentants de la Commission de la capitale nationale (CCN), du ministère de l’Environnement, de l’Office de protection de la nature de la vallée Rideau et du Collège Algonquin. Le CCT s’est réuni trois fois durant l’étude, soit les 3 décembre 2009, 17 juin 2010 et 30 novembre 2010, et a formulé des recommandations et proposé des orientations à l’équipe de l’étude sur une variété de sujets.

 

Comité de consultation publique : Le Comité de consultation publique (CCP) était composé de cinq résidents qui se sont réunis quatre fois durant l’étude, soit les 6 octobre 2009, 13 janvier 2010, 17 juin 2010 et 30 novembre 2010. Le CCP a fait part de commentaires précieux sur la meilleure façon de sensibiliser les gens dans le secteur à l’étude; il a examiné des rapports provisoires et critiqué l’étude de manière constructive.

 

Portes ouvertes : Des Portes ouvertes ont eu lieu le 3 décembre 2009 (14 personnes s’y sont présentées) et le 1er décembre 2010 (8 personnes étaient présentes).

 

Comités consultatifs du Conseil : Le Comité consultatif sur l’environnement et le Comité consultatif sur les forêts et les espaces verts d’Ottawa ont assisté chacun à deux présentations données les 9 septembre 2010 et 12 mai 2011 et les 26 juillet 2010 et 25 juillet 2011 respectivement.

 

Participation à d’autres activités de consultation municipale : Le personnel a donné des renseignements sur l’étude lors des Portes ouvertes du Plan d’action de la Ville visant la rivière des Outaouais tenues les 23, 26 et 30 novembre et 1er décembre 2009.

 

Autres consultations : Le 14 novembre 2009, une présentation a été donnée lors du Forum des associations communautaires sur la viabilité environnementale, un rassemblement annuel de toutes les associations communautaires de la ville. Le 29 avril 2010, une autre présentation a été livrée à l’Association communautaire de la plage de Westboro lors de son assemblée générale annuelle. Enfin, le 17 juin 2010, une réunion a été convoquée avec deux enseignants locaux pour connaître leur avis sur des possibilités de collaboration future dans la modernisation de mesures de GEP. Ces possibilités visaient notamment l’intégration de ces mesures dans le programme d’enseignement, en impliquant les étudiants dans les activités de contrôle et en servant de liaisons avec les conseils scolaires pour discuter de projets de GEP possibles (p. ex., débranchement de gouttières, construction de jardins de pluie).

 

Annonces dans les journaux : Des annonces dans les journaux locaux et quotidiens ont paru au sujet des Portes ouvertes (y compris des avis de début d’étude).

 

Prospectus : Des prospectus ont été élaborés avant les Portes ouvertes pour souligner les grandes lignes de l’étude et promouvoir les Portes ouvertes. Ces prospectus ont été envoyés par courriel aux personnes inscrites sur la liste d’envoi de l’étude, qui comprenait des particuliers, des groupes environnementaux et des associations communautaires. Avant la tenue des deuxièmes Portes ouvertes, des prospectus ont été affichés dans les centres communautaires et autres endroits situés dans le secteur à l’étude.

 

Bulletins électroniques : Des bulletins électroniques ont été rédigés pour présenter l’étude et informer sur les derniers développements. Ces bulletins ont été envoyés à des particuliers, des groupes environnementaux, des associations communautaires et des conseillers de quartier en juillet, octobre et décembre 2010.

 

Site Web : Un site Web a été créé pour donner accès à de l’information plus détaillée sur l’étude:

http://ottawa.ca/residents/public_consult/pinecrest_westboro/index_fr.html

 

Le public, le CCT et le CCP ont en général appuyé l’objectif et les recommandations de l’étude.

 

 

BACKGROUND

 

This project was undertaken to develop a SWM retrofit plan for the Pinecrest Creek subwatershed and adjacent Westboro area, both of which drain to the Ottawa River upstream of Westboro beach. The study area, shown in Document 1, has little or no SWM controls as the great majority of the area was built out well before current SWM requirements were in place. The consequences of this historical lack of stormwater management include:

 

 

All of these concerns are directly traceable to the highly urbanized nature of the study area and its lack of stormwater management.

 

Beyond the existing impacts of uncontrolled stormwater runoff, infill and redevelopment is also occurring in the study area, the cumulative impacts of which will further contribute to the problems noted above.

 

This Study is one of 17 Ottawa River Action Plan (ORAP) projects, as adopted by City Council on February 24, 2010: http://ottawa.ca/calendar/ottawa/citycouncil/pec/2010/02-09/13%20-%20ACS2010-ICS-ESD-0007%20-%20FINAL%20-%20ORAP.htm. Two key objectives of ORAP are to: optimize recreational use and economic development of the river, with a focus on reducing beach closures; and to maintain a healthy aquatic ecosystem, with a focus on addressing challenges presented by existing infrastructure. To achieve these objectives, ORAP identified that the impacts of uncontrolled stormwater runoff must be addressed.

 

As documented in the ORAP staff report, comments received from the public in the fall of 2009 about ORAP objectives and projects identified three key themes (emphasis added):

 

·         The City must address impacts of uncontrolled stormwater runoff as well as combined sewer overflows (CSOs). Several ORAP projects address urban stormwater; however, it is recognized that stormwater pollution is as important an issue as combined sewer overflows.

·         Residents and businesses must take responsibility for their discharges to the environment (i.e., source control). At present, the City does not have a communication plan for improving awareness of, and action on, water environment issues at the community level.  For this reason, a new project was added to ORAP to allow for improved public outreach and education on water environment matters.

·         A watershed approach is needed to ensure that the full range of pollutant sources and impacts are addressed.

 

Public consultation for ORAP included an on-line questionnaire that was also available at the ORAP Open Houses. From the results of the questionnaire, some 300 of which were completed, most respondents expressed the desire that the plan address stormwater pollution to the same degree as CSOs; and to involve residents and businesses in reducing pollution of surface waters at the lot level.

 

The Retrofit Study is a first step toward addressing the impacts of uncontrolled stormwater on the Ottawa River and its many tributaries. It identifies a long-term plan composed of a range of programs, capital projects and outreach efforts aimed at reversing or partially reversing the historical impacts of development on the Creek and local reach of the Ottawa River. The Study has also served as a pilot for the future preparation of similar retrofit plans for older areas of the City that developed with little or no stormwater management. These additional retrofit studies are also identified in ORAP.

 

With respect to Westboro Beach, it is important to note that “wet weather,” while a key contributor to the high number of beach closures, is not the only factor. Other “dry weather” factors, unrelated to wet weather, may also warrant further consideration. This Study addresses only the wet weather aspects of beach closures.

 

DISCUSSION

 

SWM retrofit refers to the insertion of various measures into established, older communities that were originally built without the infrastructure needed to mitigate the impacts of uncontrolled runoff. These impacts include degraded water quality, increased flooding and erosion, and the impairment or destruction of fish habitat. In other words, unlike greenfield development, where SWM measures are incorporated as a matter of course, the challenge of SWM retrofit is to identify effective measures that can be implemented after the fact – when there is limited land available to implement conventional SWM facilities.

 

These SWM measures are categorized by the location where they operate within the drainage system and include:

 

 

 

 

 

The overall purpose of the Retrofit Study was to recommend what combination of the above measures to apply in the study area that would provide the best solution considering a number of economic, environmental and social factors.

 

To develop such a Retrofit Plan for the study area, the following key steps were undertaken:

 

i)              Setting the Stage: Existing Conditions and SWM Retrofit Potential;

ii)            SWM Retrofit: Selection of the Preferred Scenario;

iii)          Public Consultation and Communications; and

iv)          Preparation of an Implementation and Monitoring Plan.

 

These steps were also completed to ensure consistency with the requirements of the Municipal Class Environmental Assessment (MCEA) given the anticipated identification of various capital projects. The study was conducted as a Master Plan per the MCEA process. Existing conditions were described. Problems, opportunities and a range of solutions were identified, and the various solutions evaluated to arrive at a preferred approach: the recommended Retrofit Plan. Public consultation requirements of the MCEA were also fulfilled.

 

As a Master Plan, the Retrofit Study was completed at a broad level of assessment. More detailed investigations will be required in order to fulfil the MCEA requirements for Schedule B and C projects identified within the recommended Retrofit Plan. As required by the MCEA process, the Retrofit Plan will be reviewed every five years.

 

Subject to City Council adoption of the recommended Retrofit Plan, it will be posted for a 30-day public review period as required by the MCEA.

 

i) Setting the Stage: Existing Conditions and SWM Retrofit Potential:

 

An overview of existing conditions within the study area was completed, documenting the impacted condition of Pinecrest Creek and the adjacent Ottawa River, including Westboro Beach.

 

Land use within the Pinecrest Creek subwatershed and adjacent Westboro catchments has changed over the last century or so from forest, to agriculture, to the current predominantly urban character. The study area is almost completely built-out, with only minor undeveloped areas remaining.

 

The impacts of historical development and uncontrolled urban runoff on the study area are evident and well-documented:

 

Impacts on Pinecrest Creek:

 

 

Impacts on the Ottawa River and Westboro Beach:

 

 

In addition to these on-going impacts of existing development, there are continuing infill and redevelopment pressures within the study area.

 

Following the overview of existing conditions, an assessment of the retrofit potential within the study area was undertaken. This involved completing an inventory of stream corridor infrastructure, road and development types; stream bank stability, erosion threats and flood risk. Existing storm sewer outfalls were assessed for the potential to construct new end-of-pipe facilities and land use and rights-of-way were characterized to assess the opportunities to implement lot level and conveyance retrofits.

 

ii) SWM Retrofit: Selection of the Preferred SWM Retrofit Scenario:

 

The next steps involved:

 

 

The retrofit objectives, listed in Table 1, identify the aims of the Retrofit Plan, providing direction to achieve the overall goal of a healthier creek and river and reduced closures at Westboro Beach. Associated targets (see Document 2) are numerical benchmarks that represent the desired condition to be achieved, for example, improved water quality, reduced E.coli counts during wet weather, reduced flood and erosion risks, etc.

 

Table 1: Objectives of the SWM Retrofit Plan*

 

  1.  

Reduce flood risk to public health and safety and to property along the Pinecrest Creek corridor.
  1.  

Reduce erosion impacts in the Pinecrest Creek corridor that are detrimental to property, infrastructure and stream habitat.
  1.  

Re-establish a more natural hydrologic cycle for the Pinecrest Creek subwatershed.
  1.  

Improve water quality in Pinecrest Creek and the Ottawa River by reducing the impact of stormwater runoff.
  1.  

Reduce the impacts of stormwater runoff on Westboro Beach.
  1.  

Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor.
  1.  

Increase public awareness about stormwater management and public involvement.

* Note: the numbering is for convenience and does not indicate priority.

 

The retrofit scenarios considered were comprised of different combinations and amounts of lot level, conveyance and end-of-pipe measures that would be retrofitted into the existing rights-of-way, open spaces, and a proportion of public and private properties within the study area. Table 2 identifies the list of measures included in the different retrofit scenarios (Note: The retrofit measures selected for inclusion in the various scenarios were chosen as a reasonable reflection of what measures could feasibly be implemented locally but the list is not exhaustive. There is a large and growing range of potential retrofit measures and exclusion from this exercise does not preclude their implementation, for example, the implementation of green roofs on public or institutional buildings, which may provide the same or similar benefits as the retrofit measures that were considered for this Study).

 

Table 2: SWM Retrofit Measures Comprising the Different Retrofit Scenarios

 

Type of Measure

Measures Included

Lot level

Downspout disconnection/re-direction

Rain barrels/cisterns

Porous/permeable pavement/concrete (for sidewalks and parking lots)

Rain gardens

Conveyance

Street narrowing

Infiltration measures

End-of-pipe

Wet ponds

Oil/grit separators

 

A detailed description of each type of measure is provided in Document 3.

 

A total of five different retrofit scenarios were derived to encompass a range of potential implementation levels (i.e., a greater or lesser amount of retrofit effort) for the various measures within the study area. A primary consideration was the degree of “uptake” or the extent of implementation that could reasonably be anticipated. With respect to lot level measures on private property, actual uptake will ultimately depend on a number of factors, for example:

 

 

There is the further possibility that uptake of such measures could be increased via various incentives provided by the City. The examination of potential incentives was beyond the scope of this Study but should be given further consideration as implementation proceeds. For example, the further examination of options for the recovery of stormwater and drainage costs, as recommended by the Review of the Water, Sanitary and Stormwater Rate Structure, could consider the provision of incentives to increase “uptake” of lot level measures: http://ottawa.ca/calendar/ottawa/citycouncil/pec/2010/04-13/9%20-%20ACS2010-ICS-ESD-0002%20-%20Rate%20Structure.htm.

 

For each lot level measure, the percentage uptake assigned was based upon homeowner surveys and social marketing efforts undertaken for a similar study in the City of Toronto, as well as characteristics particular to the study area.

 

With respect to conveyance measures, identification of the specific rights-of-way to (ROW) to be retrofitted was beyond the scope of the Retrofit Study. However, the total length of ROW retrofits required to achieve the desired stormwater management benefits was determined. (A further screening study will be required to determine specific feasible locations for conveyance retrofits.)

 

The potential for implementation of retrofit end-of-pipe facilities was determined through a screening process. Potential sites were screened for sufficient space to implement a new facility, existing servicing conflicts, presence of mature tree cover and property ownership to identify feasible sites to carry forward. In the end, six locations were identified as feasible locations for new end-of-pipe facilities, as shown on Document 4. Of the six candidate sites, five are located on National Capital Commission (NCC) property (NCC owns most of the Pinecrest Creek corridor) and one on City property (a subsurface facility within Elmhurst Park). Note: the NCC was consulted regarding these sites and provided various comments and conditions with respect to use of NCC land for such purposes but was unable to provide endorsement of these locations without further details that were beyond the scope of this study. Accordingly, prior to the implementation of any end-of-pipe facility on NCC property, additional study and consultation will be required.

 

The resulting five retrofit scenarios considered included:

 

1.                  Existing Conditions –or “Do Nothing:”

 

This scenario represents the existing land use and storm drainage conditions, which include the very limited stormwater management that currently exists in the study area.

 

2.                  Highest Practical Retrofit Implementation (without End-of-pipe Facilities):

 

This scenario was composed of the existing land use with the implementation of all the selected lot level and conveyance measures (as per Table 1), but excluding end-of-pipe facilities. “Highest practical” refers to the highest level of implementation presumed to be achievable, that is, not all property owners can be assumed willing to participate. This scenario provides an indication of the improvements that could be achieved by the implementation of lot level and conveyance measures only.

 

3.                  Highest Practical Implementation (with End-of-pipe Facilities)

 

This scenario was composed of the existing land use with the implementation of all the selected lot level, conveyance and end-of-pipe measures (as per Table 1). “Highest practical” again refers to the highest level of implementation presumed or determined to be feasible for all measures.

 

4.                  Moderate Implementation

 

This scenario was comprised of the same types of measures as the “Highest Practical (with End-of-Pipe) Scenario,” however, the extent of the implementation for lot level and conveyance measures was set lower. The “Moderate” implementation percentages are based upon a 5-30% reduction from the “Highest Practical” percentage uptakes assumed. For end-of-pipe opportunities, only four of the six potential end-of-pipe facilities were included in this scenario.

 

5.                  Public Property Only Implementation

 

This scenario included implementation of measures on publicly-owned lands only, thereby providing an indication of the improvements that could be achieved without any participation from private landowners and individual homeowners. Publicly-owned lands have been defined as municipal, federal, provincial and local institutional (school board) lands. As all six potential end-of-pipe facilities would be located on public lands, all were included in this scenario. Implementation percentages for lot level and conveyance measures on public lands were equivalent to those used in the “Highest Practical” scenario.

 

Modeling was then undertaken to predict the relative benefits of each scenario in terms of reducing flood risk, pollution, erosion impacts, runoff volumes, and E.coli counts at Westboro Beach. This modeling included two steps: the pollutants generated during wet weather by the study area under the five different scenarios were modelled. Total suspended solids (TSS), total phosphorous (TP) and E.coli were the representative pollutants modelled. The results for E.coli were then input to a hydrodynamic model of the river to simulate the resulting peak E.coli counts at Westboro Beach. Table 3 summarizes the results of the modeling exercises, indicating the predicted pollutant and runoff volume reductions for each retrofit scenario.

 

Table 3: Water Quality and River Modeling Results

 

Water Quality Modelling Results

Water Quality Model (WinSLAMM)

Pinecrest Creek

 

Highest Practical SWM with End-of-pipe

Highest Practical SWM no End-of-pipe

Moderate SWM

Public Property Only

% Reduction (Relative to Existing Conditions)

Runoff Volume

24%

24%

13%

5%

E.Coli Counts

35%

24%

26%

22%

Yield of TSS

43%

11%

35%

39%

Yield of TP

32%

12%

25%

25%

Water Quality Model (WinSLAMM)

Westboro Outfall River Outfalls

Highest Practical SWM with End-of-pipe

Highest Practical SWM no End-of-pipe

Moderate SWM

Public Property Only

% Reduction (Relative to Existing Conditions)

Runoff Volume

31%

31%

17%

7%

E.Coli Counts

54%

28%

46%

42%

Yield of TSS

46%

15%

42%

40%

Yield of TP

34%

15%

28%

24%

Scenario Descriptions:

Highest Practical with End-of-pipe: More lot level and conveyance measures; six end-of-pipe facilities

Highest Practical (no End-of-Pipe): More lot level and conveyance measures; no end-of-pipe facilities

Moderate: Less lot level and conveyance measures; four end-of-pipe facilities

Public Property: Lot level and conveyance measures on public property only; six end-of-pipe facilities

 

TSS=total suspended solids

TP=total phosphorous

 

River Modelling Results

Storm Events

Peak E.coli Concentration at Westboro Beach (counts/100ml)

Existing Conditions

Highest Practical SWM with End-of-pipe

Highest Practical SWM no End-of-pipe

Moderate SWM

Public Property Only

June 20, 1980 (10.8mm)

102

63

82

68

71

July 7, 1980 (28.8mm)

177

98

136

109

115

July 15, 1980 (20.9mm)

157

88

120

99

104

 

 

% Reduction (Relative to Existing Conditions)

 

 

38%

20%

33%

30%

 

 

45%

23%

38%

35%

 

 

44%

24%

37%

34%

Average

 

42%

22%

36%

33%

Notes:

1.Including background concentrations: June = 30 counts/100mL; July = 25 counts/100mL

2. 1980 rainfall data has been used as it is reflective of an “average year.”

 

The five scenarios were then evaluated and ranked according to their predicted ability to meet all of the Study’s objectives and targets (as per Table 1 and Document 2) and a number of other considerations. The evaluation addressed five main categories, including:

 

 

An overall scoring method was developed to capture the benefits and/or limitations of each of the five scenarios evaluated. The resulting detailed evaluation is provided in Document 5 and summarized in Table 4.

 

Table 4: Summary of Evaluation of Scenarios

 

Scenario

Overall Score*

Rank

Timing to Implement

Degree of Control**

Cost***

Do Nothing

116

5

none

N/A

N/A****

Highest Practical with End-of-pipe

217

1

significant

moderate

$64M

Highest Practical no End-of-pipe

195

2

significant

less than moderate

$49M

Moderate

192

3

moderate

moderate

$43M

Public Property Only

177

4

moderate

high

$31M

* Higher score is better

** Degree of control reflects amount of effort within public control

*** Cost = 50 year life cycle cost

**** This evaluation has not accounted for the “cost of doing nothing,” i.e., the cost/value of reduced beach usage, continuing flood, erosion and water quality impacts, etc.

 

Based upon the evaluation completed, the “Moderate” retrofit scenario was selected as the preferred Retrofit Plan. Although the Moderate scenario did not score highest, it was nevertheless selected as it provided the most cost-effective overall approach. In other words, it achieves significant benefits, even if less than the two Highest Practical scenarios. While additional improvements are provided by the Highest Practical scenarios, these incremental improvements are not significantly greater and were considered less cost-effective given the required significant increase in cost to achieve them. A detailed estimate of the 50 year life cycle cost for the preferred (Moderate) retrofit scenario is provided in Document 6.

 

The extent of retrofit proposed for this preferred Retrofit Plan (Moderate Scenario) includes:

 

iii) Public Consultation and Communications:

 

The public consultation undertaken for the study is described in detail below, in the CONSULTATION section of this report.

 

iv) Implementation and Monitoring Plan:

 

The preferred Retrofit Plan includes a long-term Implementation and Monitoring Plan. The purpose of the two components is, respectively, to direct the implementation of the wide range of retrofit measures recommended based upon identified priorities and to guide the monitoring required to determine overall progress in achieving the Retrofit Plan’s objectives and targets.

 

Implementation Priorities:

 

The Implementation Plan was prepared based upon the following considerations and priorities:

 

i) Provision of a long term strategy for retrofitting the study area based on a 50 year implementation time span that will allow for retrofits within the rights-of-way and on City-owned properties to be completed “opportunistically,” i.e., when roadways, City buildings and parking lots come to the end of their life cycle. In this way, the cost of retrofitting will represent only a portion of or “premium” on the total cost of replacing existing infrastructure and physical plant. Document 7 identifies all City properties within the study area. Each of the associated building roofs, parking lots, etc., has an assigned life cycle at the end of which replacement should occur with methods and materials that will contribute to achieving the Study objectives and that are appropriate to local site conditions and constraints. For example, green roofs should be considered when roof areas need to be replaced, permeable materials should be considered when parking lots are re-surfaced, roof drainage disconnected where feasible, etc. The same approach should be applied to road rehabilitation projects, i.e., as lengths of road come up for rehabilitation, consideration should be given to implementing conveyance retrofits where feasible and appropriate. While 50 years was chosen as an initial time frame to complete the implementation, it could be achieved in a shorter period of time but would result in higher overall costs for works on public property if these were to proceed in advance of the end of their projected life cycles.

 

ii) Implementation of lot level and conveyance retrofit measures on publicly-owned properties as demonstration projects to inform the community about these measures and encourage participation of private landowners. This should include pilot installations on City property to gain direct experience with such measures before their broader application. This would ideally occur at or near life cycle end, as noted above.

 

iii) Promotion of the implementation of lot level measures on private, commercial and industrial properties soon after the implementation of the pilot lot level/conveyance measure installations on public property in order to engage various communities and to realize the benefits of retrofitting the predominant land uses found in the study area, i.e., private property. (As previously noted the examination of potential incentives to private property owners was beyond the scope of this Study but should be given further consideration as implementation proceeds.)

 

iv) Planning, design and implementation of the proposed end-of-pipe facility (EoP 16) located at the northeast corner of Baseline Road and Woodroffe Avenue in the early years of the Retrofit Plan implementation, a facility that has the potential to provide considerable quality and quantity control benefits for the subwatershed.

 

v) Recognition of the need to restore natural landscape values within the Pinecrest Creek corridor and to encourage the growth and on-going survival of tree canopy in the study area as part of the Retrofit Plan; and

 

vi) Engagement of study area residents and business owners through an on-going consultation, education and outreach program.

 

The proposed Retrofit Plan is intended to provide direction to achieve a long-term vision. The suggested 50 year implementation provides a timeframe that is commensurate with the broad scope of the overall undertaking and recognizes the considerable challenges associated with retrofitting existing communities. Notwithstanding the suggested total 50 year timeframe, the initial focus will be on moving forward in five year increments. Based upon what is learned from the first five and 10 years of implementation, the 50 year timeframe would be re-revisited.

 

Following from the priorities suggested above, the Implementation Plan is comprised of four complementary components:

 

The first component, “Awareness and Engagement,” focuses on what is required to gain the individual and general public support needed to complete the Retrofit Plan. Each of the next three components focuses on a property type in which the retrofits are to occur, the SWM measures involved, potential sites and uptake targets.

 

The four components are inter-related and complementary. For example, demonstration (or pilot) projects implemented under “Leading by Example - SWM Retrofits on Public Properties” can be used to increase awareness, knowledge and enthusiasm about retrofits that could be implemented on other property types. The “Awareness and Engagement” component addresses the consultation, education, stewardship and outreach strategies that can be used in the other components. Audiences” targeted by the “Awareness and Engagement” effort will necessarily play key roles in the other implementation components whether they be on public, commercial/institutional or private residential properties if the overall Retrofit Plan is to achieve success.

 

Document 8 provides a proposed schedule that demonstrates how the suggested 50 year Implementation Plan could be achieved. Table 5 provides a summary of proposed priority projects for the first five years of implementation.

 

Table 5: Priority Projects for Initial Five Years of Implementation

 

Project

Description

1. Pilot lot level measures on City property (within study area)

 

Identify candidate facilities (buildings/parking lots, etc.) and implement and monitor the performance of lot level measures (e.g., rainwater cistern, rain garden, pervious paving/pavers, biofilter, etc.)

2. Pilot a “green street”

Identify a length of street in the study area that could feasibly be retrofit as a "green street." This could include street narrowing (to increase pervious area), other infiltration measures, pervious sidewalks, tree-planting, etc. This would require selection of an appropriate candidate site(s), public consultation, and would ideally be implemented in conjunction with a scheduled rehabilitation project.

3. Workshops and training opportunities for City staff, consultants and contractors

Provide design, construction and operational information regarding lot level and conveyance measures based upon the experience of recent applications in other similar jurisdictions.

4. Study area-wide screening exercise to determine feasible locations for right-of-way (conveyance) retrofit measures (e.g., street narrowing, "green streets," etc.)

The Retrofit Plan recommends a total of 9km of streets within the study area be retrofitted to provide water quality benefits, however, identification of the specific rights-of-way (ROW) was beyond the scope of the Retrofit Study. This exercise would examine more closely existing ROW within the study area, develop criteria for feasibility, consult internally and with the public, identify specific locations, and develop design standards for future applications.

5. Pilot study of lot level measures at a neighbourhood scale

Given the limited opportunities for retrofit end-of-pipe facilities in the study area, water quality improvement over the longer-term will also depend on the implementation of lot level measures on private residential properties. There is, however, limited experience with some of these measures. Challenges are also presented re: achieving sufficient homeowner participation. This pilot study would look at the implementation of a range of lot level measures on private property, focusing on a specific neighbourhood to assess economic incentives (willingness to pay), public acceptance, as well as the effectiveness of measures with respect to water quality improvement and runoff volume reduction. This would be a multi-year pilot including baseline monitoring, resident surveys/public awareness and engagement efforts, installation of various measures on willing participants' properties; follow-up monitoring, etc.

6. End-of-pipe facility 16: This proposed facility (see Document 4 for location) would be constructed on NCC land immediately north of Baseline Road, east of Woodroffe Avenue, where the creek initially daylights. It would provide water quality and quantity benefits by treating the large drainage area upstream of Baseline Road

Complete Class Environmental Assessment, detailed design and construction of the facility.

 

 

7.Commence Monitoring Plan (summarized in Document 9)

Begin monitoring to establish/confirm existing conditions against which the effects of the retrofit implementation can be tracked over the long term.

 

Monitoring Plan:

 

The intent of the Monitoring Plan is to track the effects of the retrofit implementation in order to assess the overall progress in achieving the Study’s objectives and targets. In other words, based upon data measured in the field as the implementation proceeds over a number of years, is water quality improving? are flood and erosion risks being reduced? are wet weather impacts on Westboro beach being reduced? Monitoring the “on the ground” results of the retrofit implementation is essential to evaluate the effectiveness of the proposed Plan and to adjust it accordingly if it is not achieving the projected (i.e., modeled) benefits. This type of approach is known as “adaptive management” and is particularly applicable given the uncertainties and complexities associated with the rehabilitation of urban subwatersheds and their receiving watercourses.

 

Adaptive management provides a means of working toward achieving desired outcomes while managing uncertainties through an iterative learning process. Successful adaptive management requires the clear articulation of the desired outcomes (objectives and targets) and the ability to adjust actions if/as monitoring results deem this necessary. The desired outcomes of the Retrofit Plan, discussed earlier in this report, were identified based on current understanding and knowledge. As the Retrofit Plan is implemented over time, field monitoring of the resulting effects and the use of the improved knowledge so gained will guide adjustments to future actions and continued implementation, if required.

 

Document 9 provides a brief summary of the proposed Monitoring Plan.

 

Implementation Roles and Responsibilities

The proposed priority projects identified in Table 5 and the overall Retrofit Plan represent a new initiative for the City for which some implementation responsibilities will require confirmation and/or integration into existing programs.

 

Potential for the “Daylighting” of Pinecrest Creek:

As an open watercourse, Pinecrest Creek ends approximately 300 meters upstream of Carling Avenue from which point it is piped for some 1400 meters under the Ottawa River Parkway until it outlets to the Ottawa River .This piping of the Creek represents a significant loss in terms of aquatic habitat and the reduced conveyance capacity considerably increases flood risk to the transitway (and candidate future light rail corridor). Specifically, it is estimated that the inlet to the piped section has a capacity to convey only the two year peak flow before overtopping and flooding of the transitway would begin. The piped section also precludes the possibility of fish migrating from the Ottawa River upstream into Pinecrest Creek.

In keeping with a key objective of this study (6. Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor.), replacing sections of this enclosed portion of the creek with an open channel, referred to as “daylighting,” was assessed on a preliminary basis given the wide range of benefits that could result, including:

Based upon a review of existing physical constraints, three sections have been identified as potential locations where daylighting the enclosed creek would be feasible, amounting to a daylighted length of approximately 900 meters. Daylighting potential is illustrated on Document 10. Given only a preliminary assessment could be competed within the scope of this Study, additional work would be required to more fully assess existing and future constraints.

Daylighting the creek has not been included in the recommended Retrofit Plan, but has been identified for consideration in the longer term, for example, to be considered in association with other projects and any on-going creek corridor naturalization efforts. Such an undertaking would ultimately be subject to the full support of the NCC, owner of almost the entire creek corridor.

 

Linkages to Other City Initiatives and Projects

The findings and recommendations of the Pinecrest Creek/Westboro SWM Retrofit Study have potential linkages to a number of on-going City initiatives and projects (beyond ORAP) including:

 

i)        Choosing Our Future: A long-term sustainability and resiliency planning initiative is being finalized for Council consideration in late 2011.  Among the goals of Choosing our Future is: “Water resources are cherished, conserved and protected.” One of the actions identified to support this goal is the transition to SWM practices that integrate extensive source (or lot level) controls to better mitigate the impacts of existing and future development. The Retrofit Plan explicitly addresses this proposed direction for the study area by identifying a long-term strategy to address the impacts of uncontrolled runoff that includes the promotion of extensive lot level controls.

 

ii) Corporate Sustainability Program:  As outlined in the Corporate Sustainability Program Road Map 2011 to 2014, this initiative has “been established to embed sustainability into the City’s organizational structure and culture – the way it does business, makes decisions, and delivers services.” Implementation of the proposed Retrofit Plan will contribute directly to fulfilling this goal as retrofit practices are incorporated into existing asset management programs responsible for the rehabilitation of roads and City properties. The Road Map also recommends the implementation of pilot projects to gain familiarity with more sustainable practices and build internal capacity. For these same reasons, undertaking pilot projects has been identified as a key priority for the initial years of the Retrofit Plan’s implementation.

 

iii) Public Transit projects: In addition to the end-of-pipe facilities the Retrofit Plan proposes on NCC property, there are a number of on-going or future transit projects that may have additional impacts on the Creek corridor including the Southwest Transitway, the West Transitway Extension, Baseline Intensive Transit and the Western LRT. NCC has identified the need for a cumulative assessment of the impacts of all of these projects on the Creek corridor that will include a landscape demonstration plan, naturalization plan, and a fisheries strategy. The Retrofit Study provides a comprehensive assessment of existing conditions within the Creek corridor from which a cumulative impact assessment could readily proceed. The recommended Retrofit Plan also offers a strategy to improve the overall health of the Creek that should contribute to compensating for the cumulative impacts of these future projects on the Creek corridor.

 

SWM Guidelines for Infill and Redevelopment in the Pinecrest Creek/Westboro Study Area

 

The Retrofit Study has focused on mitigating the historical impacts of a lack of stormwater management for existing development. There is also considerable on-going infill and redevelopment within the study area. The cumulative impact of this infill and redevelopment has the potential to negate some of the benefits of future retrofit efforts. Accordingly, SWM Guidelines for infill and redevelopment in the Pinecrest Creek/Westboro study area (as shown on Document 1) that are consistent with the objectives of the Retrofit Study are currently being developed. These will be brought forward separately to Planning Committee in the first quarter of 2012. The development of these Guidelines will involve consideration of the challenges specific to infill and redevelopment and will include consultation with the Developer Working Group associated with the on-going review of Small-Scale Infill Housing in Mature Neighbourhoods (http://www.ottawa.ca/residents/public_consult/infill/index_en.html).

 

ENVIRONMENTAL IMPLICATIONS

 

The implementation of the preferred Retrofit Plan will result in the following benefits to the local environment of Pinecrest Creek, the Ottawa River and Westboro Beach:

 

 

RURAL IMPLICATIONS

 

There are no rural implications.

 

CONSULTATION

 

Public consultation and communication efforts undertaken for the Study included the following:

 

Technical Advisory Committee: The Technical Advisory Committee (TAC) was comprised of City staff from a variety of departments, and representatives from the National Capital Commission, Ministry of the Environment, Rideau Valley Conservation Authority and Algonquin College. The TAC met three times during the study - on December 3, 2009, June 17, 2010 and November 30, 2010 and provided advice and guidance to the study team on a range of issues.

 

Public Advisory Committee: The Public Advisory Committee (PAC) was comprised of five residents and met four times during the study – on October 6, 2009, January 13, 2010, June 17, 2010 and November 30, 2010. The PAC provided valuable comments on how best to reach people in the study area, reviewed interim reports, and constructively critiqued the study.

 

Open Houses: Open Houses were held on December 3, 2009 (attended by 14 people) and December 1, 2010 (attended by eight people). Comments received at the Open Houses are summarized in Documents 12 and 13.

 

Advisory Committees of Council: Presentations were made to the Environmental Advisory Committee on September 9, 2010, and May 12, 2011, and the Ottawa Forest and Green Space Advisory Committee on July 26, 2010 and July 25, 2011.

 

Participation in other City consultation events: Staff provided information about the study at Ottawa River Action Plan Open Houses held November 23, 26, and 30 and December 1, 2009.

Other Consultations: On November 14, 2009, a presentation was made to the annual Community Associations Forum on Environmental Sustainability, a gathering of City-wide community associations. On April 29, 2010, a presentation was made to the Westboro Beach Community Association at its Annual General Meeting. Finally, on June 17, 2010, a meeting was held with two local teachers to seek their advice regarding opportunities for potential future collaboration relating to retrofitting SWM measures. This included possible tie-ins to the curriculum, involving students in monitoring activities and liaising with School Boards on potential SWM projects such as disconnections of downspouts or the construction of rain gardens.

Newspaper Advertisements: Advertisements for the Open Houses (including the Notice of Study Commencement) were placed in local and daily newspapers.

 

Flyers: Flyers were developed in advance of the Open Houses to provide basic information about the study and promote the Open Houses. These were e-mailed to those on the study mailing list, which included individuals, environmental groups and community associations. Prior to the second Open House, flyers were posted at local community centres and other venues in the study area.

E-Newsletters: E-newsletters were developed to introduce the study and provide progress updates. These were sent to individuals, environmental groups, community associations and ward Councillors in July 2010, October 2010 and November 2010.

Website: A website was created to provide access to more detailed information about the study:

http://ottawa.ca/residents/public_consult/pinecrest_westboro/index_en.html

 

Document 11 provides a summary of comments received from the general public and TAC and PAC members. Documents 12 and 13 provide a summary of comments received at the Open Houses.

 

 

LEGAL IMPLICATIONS

 

There are no legal impediments to implementing any of the recommendations in this report.

 

RISK MANAGEMENT IMPLICATIONS

 

There are no risk management implications associated with this report as it represents an overall Retrofit Plan that will guide various projects and programs. Risks associated with specific projects and programs will be identified and managed as they come forward for implementation.

 

CITY STRATEGIC PLAN

 

Implementation of the proposed Retrofit Plan will contribute to achieving the following objectives in the City’s Strategic Plan:

 

i) Solid Waste and Environment Objective 3: Protect the water environment and source water supply. The Retrofit Plan will protect the water environment by improving water quality, reducing flood and erosion risks, and improving the overall health of Pinecrest Creek and the Ottawa River.

ii) Solid Waste and Environment Objective 4: Meet the intent of the Leadership in Energy and Environmental Design (LEED) standard by 2020 for existing City-owned buildings to support the implementation of Council-approved environmental goals and targets. Implementing SWM retrofit measures at City-owned buildings will contribute to achieving this objective.

 

TECHNICAL IMPLICATIONS

 

N/A

 

FINANCIAL IMPLICATIONS

 

The recommended Retrofit Plan, if adopted, will provide the basis for annual budget requests to support the long-term implementation of the various components of the Plan (initial pilot projects, capital projects, education/public outreach, monitoring of overall effectiveness, on-going maintenance of implemented projects, etc.).

 

For the 2012 budget process, funding to begin implementation of the Retrofit Plan has been included for consideration in the draft rate budget in the amounts of $2M for 2012, $2M for 2013 and $9M for 2014. Earlier estimates of projected annual costs for stormwater retrofit were also accounted for in the Cost, Rate and Revenue Study (ACS2010-ICS-ESD-0002).

 

SUPPORTING DOCUMENTATION

 

Document 1    Study Area

Document 2    Study Objectives and Targets

Document 3    Description of SWM Retrofit Measures

Document 4    End of Pipe SWM Retrofit Locations

Document 5    Criteria and Scoring Used for Scenario Evaluation

Document 6    Life Cycle Costing for the Preferred (Moderate) Retrofit Scenario

Document 7    City Properties within Study Area

Document 8    Implementation Schedule for 50 Year Plan

Document 9    Monitoring Program Summary

Document 10  Potential for Creek Daylighting

Document 11  Comments Received and Responses

Document 12  Comments Received from Open House No. 1

Document 13  Comments Received from Open House No. 2

Document 14  Pinecrest Creek/Westboro SWM Retrofit Study (May 2011) (Distributed separately and held on file with the City Clerk)

 

 

DISPOSITION

 

Planning and Growth Management will work with Infrastructure Services and Environmental Services to undertake the priority projects identified for the first five years of implementation and to confirm departmental responsibilities for the longer-term implementation of specific components of the Retrofit Plan.

 

Planning and Growth Management will proceed with completing the Eastern Subwatersheds SWM Retrofit Study making use of what has been learned from the Pinecrest Creek/Westboro Study.

 

Infrastructure Policy and Transportation Planning staff will work together to prepare a cumulative assessment of the impacts of future transportation and SWM retrofit projects on the Creek corridor as requested by the NCC.

STUDY AREA                                                                                                       DOCUMENT 1

Note: all Documents (save Document 7) referenced from Pinecrest Creek Westboro Stormwater Management Retrofit Study, J.F. Sabourin and Associates Ltd, Final Report, May 2011, provided under separate cover.


STUDY OBJECTIVES AND TARGETS                                                           DOCUMENT 2

 

1.     Reduce flood risk to public health and safety and to property along the Pinecrest Creek corridor.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

A)      Flood risk

With potential infill and redevelopment, there is a need to ensure that flood risk to public health and safety and to property is not increased.

Flood elevations

Flood flows

 

2010 flood levels generated in Pinecrest Creek/Westboro SWM Retrofit Study

Maintain or reduce existing flood elevations

Maintain or reduce existing peak discharge rates for all design events, particularly high flows

 

B)      Flood-plain Storage

Floodplain storage attenuates peak flows as the flood wave moves downstream through the system; maintaining this feature of the floodplain is important to avoid peak flow increases from future potential works within the corridor

Riparian storage volumes for 2 to 100 year events

 

As determined from 2010 hydraulic modelling generated in Pinecrest Creek/Westboro SWM Retrofit Study

 

 

Maintain existing riparian storage volumes for 2 to 100 year events

 

2.   Reduce erosion impacts in the Pinecrest Creek Corridor that are detrimental to property, infrastructure and stream habitat.

Indicator

Rationale

Measurable Parameter

Existing Conditions

Target

A)      Sediment Regime and Sediment Size

Sediment sources and sediment transport need to be maintained in dynamic equilibrium to control loadings to reaches.

Pebble count; visual inspection of channel substrate; sediment transport samples in-situ;

photo record

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

General maintenance of existing substrates; no increase or decrease in average sediment size (D50) of more than 10 percent compared to existing conditions

Maintenance of sediment transport rates over a range of transport events based on measured samples as opposed to theoretical transport results based on equations

 

 

Substrate Composition

 

 

 

 

 

 

 

 

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

- Due to the dynamic nature of the channel substrate, dimensional adjustment is anticipated

- As a performance threshold, adjustment in grain size should not exceed an order of magnitude over the long term; short-term adjustments should not increase or decrease by more than 10 percent of the D50 size fraction compared to existing conditions.

B)      Channel Stability and Erosion Potential

Channel stability is a function of time series flows and sediment regime, stabilizing bank features (e.g. woody vegetation, artificial hardening).

 

Erosion potential needs to be reduced to more natural levels to stabilize and reduce erosion damage and loss of riparian/floodplain lands.

 

Maintain channel stability to protect municipal and NCC infrastructure, to reduce annual maintenance costs and increase longevity of infrastructure

Cross-sectional form and area from available survey data

 

 

 

 

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

- Cross-sectional area should not increase or decrease in excess of 20%

- Cross-sectional form should be maintained within accepted limits (visual comparison only)

 

Longitudinal Profile

 

 

 

 

 

 

 

 

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

- Inter-pool and energy gradients should not differ in excess of 5%

 

- Riffle grades should not increase or decrease in slope more than 20%

- Riffle crest elevations should not increase or decrease to the point of impacting upstream bedforms (visual analysis)

Lateral Migration

(meandering)

 

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

- Annual migration rates exceeding 15 cm per year in pools and 5 cm per year in riffles will trigger an assessment of the channel conditions at the site

 

Cross-sectional measurement of erosion-prone sites; review of hydrologic and hydraulic data to determine changes to erosion potential over time

 

Based on retrofit work, two or three sensitive reaches should be measured prior to implementation to determine baseline.

No significant increase in bed and bank erosion; no significant decrease in erosion potential which could cause sedimentation in problematic areas within the channel

C)      Aquatic Habitat

Improve the quality and quantity of in-stream aquatic habitat.

Improving the potential for a sustainable fishery is a longer term objective.

For example:

Average pool depth

Percent cover

Bank stability

Given the existing degraded conditions in the creek corridor, the immediate focus is reducing the impacts of uncontrolled runoff– see other objectives and targets.

To be developed in future, subject to progress in achieving water quality and quantity targets and mitigating existing barriers.


3.     Preserve and/or re-establish a more natural hydrologic cycle for the Pinecrest Creek subwatershed.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

A)      Peak Flows and Runoff Volume for more Frequent Storms

Reduce flashiness of runoff from the watershed

Runoff volumes and peak flows for more frequent storms (e.g. up to 25 mm)

Retention assumed between 1.5-4.5 mm

Detention assumed to be 0 mm

 Retain runoff from first 10 mm of rain.

Detain runoff from next 15 mm of rain.

(To be confirmed – subject to model calibration and confirmation of existing condition watershed peak flows and runoff volume targets)

B)      Effective imperviousness (EI)

 The proportion of a catchment covered by impervious surfaces directly connected to the stream by storm sewers

The degree of effective imperviousness can greatly impact the timing and amount of flows and pollutants into the receiving watercourse.

Area difference between total impervious area and indirectly connected area

 Will be assessed on a site by site basis for infill and redevelopment areas

 

 

As a minimum, existing effective impervious should not be increased; to be implemented as a requirement for infill and redevelopment

 

 

4.   Improve water quality in Pinecrest Creek and the Ottawa River by reducing the impact of runoff.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

Instream Nutrients, Total Suspended Sediment, Total Phosphorus

Targets are linked to achieving fish community targets, aesthetics and non-eutrophic conditions and avoiding the creation of in-situ contaminant concerns

 

TSS

TP

 

Pinecrest Creek:* Wet weather TSS- (min: 20 mg/L; max: 520 mg/L; avg: 189 mg/L)

Wet weather TP - (min: 0.03 mg/L; max: 0.57mg/L; avg: 0.10 mg/L)

Wavell outfall:*

Wet weather TSS- (min: 28 mg/L; max: 450 mg/L; avg: 224 mg/L)

Wet weather TP - (min: 0.05 mg/L; max: 0.37mg/L; avg:0.15 mg/L)

TSS = less than 25 mg/L change from background

 

TP =0 .03 mg/L (85th percentile)

 

 

*River Input Monitoring Program: 1998 Ottawa River. Regional Municipality of Ottawa-Carleton (RMOC), 1999.

5.   Reduce the impacts of runoff on Westboro Beach.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

Instream E. coli

(at Pinecrest Creek Confluence and Adjacent Outfalls to Ottawa River)

 

Setting targets to approach the swimming beach PWQO in non-beach areas ensures that risks of contracting disease from incidental exposure to recreational waters are reduced (e.g. boating, water skiing, private dock swimming)

 

 

E. coli

Pinecrest Creek:*

Wet weather- (min: 1000 cts/100 mL; max: 8400 cts/100 mL; avg: 3054 cts/100 mL)

Wavell outfall:*

Wet weather - (min: 1000 cts/100 mL; max: 135,000 cts/100 mL; avg: 8132 cts/100 mL)

Achieve PWQO (E.coli= 200cts/100mL) (80th percentile)

E.coli (max.) not to exceed 2000 cts/100 mL

 

To be confirmed subject to potential new Guidelines for Canadian Recreational Water Quality, and resulting modelled count at Westboro Beach.

*River Input Monitoring Program: 1998 Ottawa River. RMOC, 1999.

 

6.   Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

A)      Riparian Vegetation

 

 

The Environment Canada Habitat Guideline recommends the natural vegetation within 30 m of a watercourse be retained or re-established on each side of a watercourse for 75% of its overall length. (This target was developed at a watershed level and may not be appropriate to or achievable within an urban subwatershed.)

Riparian vegetation (field visits or aerial photograph interpretation)

The City Stream Watch Annual Report found that 19% of the stream sections were in natural condition, 46% were altered and 35% were highly altered, (although there may not be a direct equivalency of these values to the extent of existing riparian cover).

To be determined.

B)      Tree Canopy

 

Increased tree canopy in urban areas can reduce runoff volume by intercepting rainfall, particularly for small events

 Area of tree canopy.

 Existing tree canopy = 6 %

Net increase in canopy

 To be developed.

 

7. Increase public awareness about stormwater management and increase public involvement.

Indicator

Rationale

Measurable Parameter

Existing Condition

Target

A)      Increased Public Awareness

Increased public awareness will lead to greater success and uptake of SWM Retrofit Plan recommendations

 

N/A

 

N/A

To be developed through monitoring and reporting

B)      Increased Public Involvement

Increased public involvement required for successful implementation of SWM retrofit

 

N/A

 

 

N/A

To be developed through monitoring and reporting

DESCRIPTION OF SWM RETROFIT MEASURES                                      DOCUMENT 3

 

Lot Level Measures (Private and Public Lots)

 

Downspout Disconnection/Redirection

 

Downspout disconnection/redirection is the diversion of flow from roof tops to pervious areas, as shown in Figures 1a and b. This SWM measure prevents the routing of stormwater onto impervious surfaces which drain directly to the storm sewer system (ref. Credit Valley Conservation and Toronto and Region Conservation Authority. 2010. Low Impact Development Stormwater Management Planning and Design Guide, Version 1.0). To produce a measurable benefit, simple downspout disconnection requires a minimum flow path length of 5 m across a pervious area before flowing onto an impervious surface or into the storm sewer system. With respect to discharge and seepage, discharge locations for roof downspouts should be a distance of 3 m away from building foundations, however, this may not be necessary if the topography slopes 1 to 5% away from the building (ref. Credit Valley Conservation and Toronto and Region Conservation Authority. 2010. Low Impact Development Stormwater Management Planning and Design Guide, Version 1.0).

 

Text Box: • In the study area, the percent of downspouts that are currently connected or directed to pervious surfaces was estimated from the lot level survey information. It was assumed that the topsoil infiltration rate is equal to or greater than 25 mm/hr, and as such no soil amendments would be required for this lot level control to function effectively. (The potential low permeability of the underlying fine-grained sediments that exist in much of the study area was taken into account in the water quality and water quantity modelling.)    Figures 1a and 1b Downspout Redirection

 

Rain Barrels and Cisterns

 

Rain barrels and cisterns are rain harvesting BMPs that capture roof runoff from frequent storm events and temporaily store it for reuse on site. This practice reduces runoff and pollutants, and can provide a benefit in terms of reduced water consumption. Figure 2 shows a private installation of a rain barrel, and Figure 3 shows the installation of a public cistern application.

 

Text Box: • Two rain barrels were implemented on residential properties, sized at 208 L (55 gallons) each, and located at the front and rear of the house to collect runoff from either side of a typical roof. The water usage calculated for these barrels was based on the average lawn irrigation needs of 25 mm/week. Cisterns were located on institutional and industrial lands and were sized to capture three days of average (1980 City of Ottawa data) roof runoff. Based on an averaged roof size (for the study area), such cisterns would need to be 7,570 L (2,000 gallons) in size. The same average water usage used for the rain barrel calculation of 25 mm/week was used for the cistern calculations. Figure 2: Connected Rain Barrel Application

Cistern_Ryerson.jpg

 

 

 

 

 

 

 

Figure 3: Connected Cistern Application

 

 

 

 

 

Rain Gardens (Bioretention)

 

Rain gardens, or bioretention areas, are designed to include hydrophilic (water-loving) native species and amended soils in human-made depressions to aid in capturing rainfall runoff. This lot level measure decreases peak flows through additional on-site storage, and reduces pollutant loads through both runoff volume reduction and filtration prior to discharge. Figures 4a and 4b provide examples of Rain Gardens.

 

rain-garden-from-wwwText Box: • The rain gardens are designed for residential and institutional lots to receive lot level runoff and rain barrel or cistern overflow. For the evaluation of the SWM retrofit scenarios, it was assumed that each rain garden would have a surface area of 5.6 m2 (60 ft2) and would capture 50% of runoff from the adjacent landscaped areas (e.g. front lawns).

Figure 4a: Rain Garden

 

Rain Garden

 

 

 

 

 

 

 

 

                                                                                                      Figure 4b: Rain Garden

 

 

 

 

 

 

Porous and Permeable Pavement/Concrete

 

Porous or permeable pavement or concrete, an alternative to impervious products, allows some surface runoff to flow through its surface to be stored in a granular base prior to being released slowly to the storm sewer system or infiltrated into the native soil beneath. An example of the use of permeable pavers in a walkway and parking lot setting can be seen in Figure 5a. Figure 5b shows water infiltrating through a slab of porous asphalt.

 

Text Box: • For the evaluation of the SWM retrofit scenarios, it was assumed that porous pavement would be installed in the following runoff source areas: driveways, parking lots and sidewalks within various land uses e.g. residential, institutional, commercial and industrial.

permeable_pavementFigure 5a: Porous Pavers used for a Walkway and Parking Area

 

 

 

 

 

 

 

 

 

 

 

Figure 5b: Cross-Sectional View of Porous Asphalt

 

 

Conveyance Measures

 

Grass Swales

 

Grass swales are vegetated, shallow, open channels designed for conveyance and treatment of stormwater runoff, particularly from roadway drainage. Grass swales reduce runoff volumes and pollutant loads by filtration through the vegetation and infiltration into the underlying soils, and provide discharge at lower rates. Grass channels are similar to ditch systems; however, they have lower design velocities for water quality treatment due to their flatter side and longitudinal slopes. See Figure 6a for an example of a roadside grass swale, similar to the existing ditches within portions of the Pinecrest and Westboro subwatersheds. Figure 6b is a digitally prepared image which illustrates the option of installing a sub-drain below a grass swale.

Text Box: • For the SWM retrofit scenario evaluations, the study area’s existing roadside grassed ditches and swales were modelled as “grass swales” which were represented as 30 cm (1 ft.) deep with a 0.9 m (3 ft.) bottom width and 4:1 side slopes. The extent of existing roadside grass ditches/swales assumed for the scenarios was based on the study area data in the City of Ottawa GIS data base. Grass ditches /swales are predominately located within residential areas.

IRS-Lot-3

Figure 6a: Roadside Grass Swale

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6b: Digital Rendition of a Grass Swale with Sub-Drain

 

 

Infiltration Trenches

 

Infiltration trenches are long, narrow, rock-filled trenches (Figure 7) that receive stromwater runoff from roadways or landscaped areas. As the trenches have no outlet, the runoff is stored within the voids of the rocks and infiltrates into the soil below. These trenches are effective in removing fine particles and associated pollutants.

 

infiltration-trench-_original

Text Box: • For the SWM retrofit scenario evaluations, the infiltration trenches were sized at 10.7 m (35 ft) long, 0.5 m (1.64 ft) wide and 0.6 m (2 ft) deep, and the sub-surface native soil infiltration rates were set as 2.5 mm/hr (0.1 in/hr). The lateral dimensions were based on average residential lot widths less the driveway width and the depth was set to ensure that any underground structures or lateral services would not be compromised.

 

                                                                                    Figure 7: Side Yard Infiltration Trench

 

Street Cleaning

 

Streets are a significant contributor of pollutants to urban runoff. Street cleaning can reduce this impact. The City of Ottawa uses tandem street cleaning machines (shown in Figure 8) that make use of brooms and vacuums.

streetCleaning.jpg

Text Box: • The street cleaning schedule currently used by the City of Ottawa is to clean streets in commercial or industrial areas once every two weeks and to clean streets in residential and institutional areas once every four weeks. This street cleaning schedule was the one assumed for all the SWM retrofit scenarios. The reason for this is explained in Section 3.2.  

 

 

Figure 8: Street Cleaning

 

Street Narrowing

 

Street narrowing reduces impervious cover, stormwater runoff, and associated pollutant loads. To maximize the benefits of street narrowing, the narrowed area can be designed to promote increased infiltration/filtration via granular media, plantings, etc. Figure 9a demonstrates a simple example of street narrowing, Figure 9b demonstrates a more ambitious design, which incorporates a vegetated infiltration trench in the narowed area.

 

street narrowingText Box: • For the SWM retrofit scenario evaluations, it was assumed that the narrowing would be 0.5 m on either side of the street.

                                                                                                Figure 9a: Street Narrowing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 9b: Street Narrowing with a Vegetated Infiltration Trench

 

 

End-of-Pipe Facilities

 

Oil and Grit Separators

 

Oil and Grit separators (OGS) are underground structures installed in conventional storm sewer systems to improve water quality downstream (shown in Figure 10). They come in different designs, sizes and materials; some are commercially available and others are custom designed and built.

 

ecosep_02OGS consists of separate chambers through which stormwater is conveyed to remove coarse sediments (grit), oils and other buoyant pollutants (floatables). The principal site constraints in using OGS is the depth of the drainage outlet that the device is to be connected to and the drainage area to be treated. The outlet must be sufficiently deep to accommodate the required size of the unit. In terms of SWM benefits, OGS provide quality control by capturing particulates, oil and grease. OGS are one of few SWM features that can effectively remove (retain) oil and grease from stormwater.

 

Figure 10: Oil and Grit Separator

 

Text Box: • There is a variety of proprietary and non- proprietary OGS available ranging from chamber designs to manhole types. The different types incorporate some combination of filtration medium, hydrodynamic sediment removal, oil and grease removal, or screening to remove pollutants. • Non-proprietary systems include deep sump catch basins. • Proprietary systems include: CDS® Technologies Stormceptor® Vortechs™ Downstream Defender™ These systems represent only some of the systems currently available. CDS® units were the only OGS systems whose specifications were used in the SWM scenarios due to the size of drainage areas involved, as described below. The presentation of the CDS® systems or any of the other OGS systems in this SWM retrofit document in no way represents or reflects an endorsement.

 

 

 

 

 

 

 

 

 

 

 

 

Screening Action Type of OGS (e.g. Continuous Deflection Separation Systems)

 

Continuous Defelection Separation (CDS) systems (shown in Figure 11a) are an example of screening action type of OGS. The CDS systems are designed to treat stormwater runoff from relatively large drainage areas. Stormwater runoff is conveyed through the CDS system’s diversion chamber, where all flows are passed through the separation chamber, which screens, separates and traps sediments and debris. CDS units can be installed as pre-cast or cast-in-place structures, configured as in-line, off-line, grate inlet or drop inlet and have multiple screen aperature sizes (example in Figure 11b). In-line units can treat flows from drainage areas up to 12 ha, while single off-line units can treat drainage areas up to 120 ha. The use of multiple pre-cast, or larger cast–in-place off-line units, allows for treatment of drainage areas in excess of 120 ha.

 

CDS_2

Text Box: • Specifications drawn from the CDS® Technologies literature were used to define the OGS used in the SWM Retrofit Scenarios. For the evaluation of the Scenarios the CDS units were included in the “other controls” option of the water quality assessment program. A removal rate of 80% influent TSS was assumed, which is an Enhanced Protection Level as per the Ministry of the Environment Stormwater Management Planning and Design Manual (MOE 2003). The presentation of the CDS® systems or any of the other OGS systems in this SWM retrofit document in no way represents or reflects an endorsement.

Figure 11a: Typical Schematic of a CDS Unit

 

Figure 11b: Typical Installation of a CDS Unit

Wet Ponds

 

Wet ponds are end-of-pipe facilities used to treat runoff from drainage areas of at least 5.0 ha, and preferably greater than 10 ha. If adequate space is available, these facilities can be designed and sized to provide erosion control, quality control and flood control benefits. The ponds shown in Figures 12a and 12b are examples of typical wet ponds in residential and commercial settings.

 

Text Box: • For the evaluation of the SWM retrofit scenarios, the wet ponds were modelled in the “other controls” option of water quality assessment program. A removal rate of 70% of influent TSS was assumed, representing a Normal Protection Level as per the Ministry of the Environment Stormwater Management Planning and Design Manual (MOE 2003). %7B0E4F2601-41D9-4083-B30B-858B1843E9EA%7D

Figure 12a: Wet Pond in a Commercial Setting

 

 

 

 

Figure 12b: Wet Pond in a Residential Setting

 

 

Photo Credits

Figures 1a and 1b:http://www.amazoneaves.com/images/ddp01.jpg

 

Figure 2: http://www.devilsbackyard.com/2010/04/22/rain-barrels-for-your-home

 

Figure 3: http://www.lakecountyil.gov/Stormwater/LakeCountyWatersheds/BMPs/RainBarrelCistern.htm

 

Figure 4a: http://baywatersheds.org/wp-content/uploads/2010/07/rain-garden-from-www.carolstream.org_.jpg

 

Figure 4b: www.sws-sssd.org

 

Figure 5a: http://greenvalues.cnt.org/national/images/permeable_pavement.jpg

 

Figure 5b: http://www.inhabitat.com/wp-content/uploads/perviouspaving-ed04.jpg

 

Figure 6a: http://www.preinnewhof.com/images/Projects/Porous-Pavement-IRS/IRS-Lot-3.jpg

 

Figure 6b: http://www.wbdg.org/resources/lidtech.php

 

Figure 7 http://www.cob.org/services/environment/water-quality/homeowner-incentive-program.aspx

 

Figure 8: http://www.westlafayette.in.gov/egov/gallery/1251236693426196.jpg

 

Figure 9a:  http://www.lakelandgov.net/publicworks/Traffic/TrafficCalming/TrafficCalmingProjects.aspx

 

Figure 9b: http://switchboard.nrdc.org/blogs/rhammer/managing_stormwater_and_making.html

 

Figure 10  www.watertectonics.com

 

Figure 11a: http://www.shawpipe.com, 2010

 

Figure 11b http://www.contech-cpi.com/Products/Stormwater-Management/Treatment/CDS.aspx

 

Figure 12a: http://www.rwmwd.org/index.asp?Type=B_BASIC&SEC=%7B82D57109-E41C-4CE8-B838-477FF4A2DDFD%7D

 

Figure 12b:http://www.co.thurston.wa.us/stormwater/facilities/facilities-home.html

END OF PIPE SWM RETROFIT LOCATIONS                                              DOCUMENT 4

CRITERIA AND SCORING USED FOR SCENARIO EVALUATION       DOCUMENT 5

LIFE-CYCLE COSTING FOR THE PREFERRED

(MODERATE) RETROFIT SCENARIO                                                           DOCUMENT 6

 

 

CITY PROPERTIES WITHIN STUDY AREA                                                DOCUMENT 7

IMPLEMENTATION SCHEDULE FOR 50 YEAR PLAN                            DOCUMENT 8

 

MONITORING PROGRAM SUMMARY                                                          DOCUMENT 9

 

POTENTIAL FOR CREEK DAYLIGHTING                                                 DOCUMENT 10

 

COMMENTS RECEIVED AND RESPONSES                                              DOCUMENT 11

 

Event

Source

Comment

Response

PAC mtg

June 23, 2009

PAC member

July 3, 2009

 

What is the source of the E.coli in Pinecrest Creek?

 

If we employed the methodology of the study that was done for Lake Huron can we determine what % of the Ecoli is human, wild life or agricultural source?

Given the urban nature of the subwatershed, it is likely that E.coli in the creek derives from a number of sources including domestic pets, and urban wildlife/water fowl. Human sources can also contribute if/when cross-connections exist (i.e., a sanitary sewage lateral pipe from a home or business is mistakenly connected to the storm sewer).

While there are various methodologies that can identify the specific source of E.coli, this knowledge would not be anticipated to result in a significant change to the amount and types of SWM retrofit measures being evaluated for implementation (e.g., lot level, conveyance, and end-of-pipe measures).

If some of the E.coli are from Human origins what changes in City procedure are required to be able to trace down the sources, e.g., mandatory cooperation in dye testing homes and business.

 

Given the typically intermittent nature of flows from cross-connections, it can be challenging to track down the source. When/if discharges of sewage are noted and reported, the City does undertake “search and destroy” efforts to eliminate the discharge.

Besides biological contaminates, e.g., E.coli and other bacterial/viruses, what other substances (metals, anions, and other organic compounds) are present in the

creek waters?

The stormwater that runs off into the creek is typical of untreated, urban drainage and includes a range of pollutants including suspended solids, metals, oil and grease, chlorides, nutrients, etc.

What are the options for treatment of the Pinecrest Creek outflow into the Ottawa River and where would they be done?

 

In subsequent stages of the study, various measures and opportunities have been considered and evaluated to determine the preferred approach to treating stormwater runoff including lot level, conveyance and end-of-pipe facilities.

It is my understanding that there will be modeling done for the flow and outflow of the creek. However, as I have mentioned in the past what is missing from studies to date is the actual measurement of E.coli flow as can be determined by dye dilution studies. Modeling and reality may have a significant differences!

Measurements of E.coli in Pinecrest Creek and at various outfalls during wet weather have been used to ensure that the modeling undertaken is reflective of actual conditions in the creek and river.

PAC mtg

June 23, 2009

PAC member

July 3, 2009

 

What is the effect of rainfall on Ecoli outflow/vol from Pinecrest Creek, e.g., when there is rain what is the profile of E.coli level in the waters from Pinecrest Creek. What volume of water "flushes" Pinecrest Creek. Are there portions of the creek that have higher Ecoli levels and if so why?

E.coli readings can vary greatly depending on a number of factors such as the amount/intensity of rainfall, the time that has passed since the last rainfall, the time of year, presence of cross-connections, etc. For the purposes of modeling the “existing condition” an average E.coli count, based upon available creek and outfall monitoring data, was used in the water quality modeling.

Steps 1 and 2

Report

City of Ottawa, Env. Sustainability

December 24, 2009

There has been discussion of the pre urban development and existing condition hydrology.  The only assessment I see in the draft report is the 100 year flood line.  A comparison of the range flow events statistics – flow, volume, etc. would provide the pre and existing condition reference as a basis for future targets.

This has been documented in the final study report.

 

The geomorphic assessment regarding the culvert flags the sedimentation problem in one of the twin barrel in a number of locations.  I believe I heard confirmation that there was an assessment of the hydraulic capacity compared to design events including the 100 year event.  Please confirm capacities of existing conditions relative to the 100 year event.

This has been provided in the final study report.

Given the capacity of the culverts, I anticipate discussion of the morphology in terms of longer term risks.  If the culvert has become a stable in side bend / point bar that still functions during critical flows, is the sedimentation in it a problem?

 

Sedimentation in the culvert referred to has reached an equilibrium state and while watching it over the years the level of sediment in the east cell has not changed to any discernable degree. The discussion relating to sedimentation in culverts is more centred around the impact of an environment that has gone from erosional (excess energy) to one that is depositional (minimal energy for transport). Under the proposed conditions, the sedimentation of culverts is predicted to occur from the modelling of sediment transport and therefore there is a need to be proactive with culvert assessment and maintenance to ensure blockages do not occur.

 

It is understood that trees that become obstacles to flow as the channel adjusts cause excessive local erosion and removal is an appropriate solution.  The question of encroachment is one that needs further clarification / discussion.  There is the line of thought that the flood plain is created by the creek as it moves through its meander belt.  Given this is the case and it is adjusting to its new size, when is it appropriate to just let it do the moving and when are remedial works required or alternatively when are the costs of major works to adjust it appropriate / cost effective?

 

The fourth figure? GPS 439023 – 5023221 looks like the Transit way berm that is out of date, works have been completed?  Is this the only case?

 

When there is nothing in the way that is at risk and there are no concerns about the overall health of a creek, it is prudent to let it do what it wants to do to adjust to new flows—the creek knows what it wants to do and by intervening we are still somewhat guessing at the end product. By far the best management strategy is to let it go and when we see what it is doing then we can help it along if there are concerns. That strategy requires buy-in by all involved because there are a number of potential issues, including erosion/deposition within the creek itself, but also the potential for treefall, sedimentation within culverts and sediment loading of the outfall of Pinecrest Creek at the Ottawa River.

 

The data sheets have been updated to indicate which locations underwent remediation in 2008. They are all still considered areas of concern until the final phase of the monitoring is completed in 2011.

Steps 1 and 2 Report

City of Ottawa, Natural Systems, PGM

January 25, 2010

p.i. - Task number 2.  Should this not follow some of the subsequent tasks, or is it referring to options already developed under the Centrepointe project?

 

This task refers to determining the various types of retrofit measures considered as best suited to this study area (lot level, conveyance, end-of-pipe) as well as identifying specific opportunities where they can be implemented (e.g., end-of-pipe retrofits can only be implemented where there is sufficient land available near a given outfall).

p.1 - Under study area, the report says that the subwatershed area is 1,920 ha.  The Existing Conditions Appendix gives 1,440 ha as the "drainage area."  Discrepancy?

 

This has been corrected: Pinecrest subwatershed= 1,920ha; Westboro outfalls total drainage area = 450ha.

 

Table 4.1: For the Floodplain Storage indicator, I'm not sure what the rationale means.  Do we want more frequent "spill[s]" into the floodplain, or fewer?  How does the target related to the rationale and the measurable parameter?

 

The description for this indicator has been revised to more accurately reflect its intent:

Floodplain storage attenuates peak flows as the flood wave moves downstream through the system; maintaining this feature of the floodplain is important to avoid peak flow increases from future potential works within the corridor.

 

For Sediment Regime and Sediment Size. The connections between the rationale, the measurable parameters and the targets might not be obvious to a lay audience.  For example, what does it mean to maintain "sediment sources and sediment transport... in dynamic equilibrium...?"  How does it relate to pebble count, and what is a "pebble count?"  What is "substrate dimensional adjustment?"  More generally, is this indicator really necessary, or does the channel stability and erosion potential indicator provide the necessary information necessary for adaptive management?  Is it really practical to monitor against the proposed targets, and will it get done?  Is anyone really going to look for 5 cm changes in substrate depth?

Sediment sources and transport is dynamic in that sources and transport are not continual but somewhat random in step length and distance travelled. This is because of the number of variables that have to be operating in tandem for transport to occur. Sediment sources are those areas that provide sediment (usually in controlled volumes) to the stream for transport. When transporting sediment the stream uses energy to maintain the transport relationship; that energy used in transport is lost to the erosion part of the energy cycle and therefore less erosion can occur. If the sediment sources are cut off and there is no delivery to the streams then the stream will erode the bed and banks at accelerated rates to gather sediment for transport. So, when a basin which was once agricultural (to use an extreme example) becomes paved as a residential development site, the sediment supply to the channel is lost from overland flow sources and the response by the creek is to erode the bed and banks.

 

A pebble count is a means of determining the grain size characteristics of the bed for larger-sized particles, those that are too large to put through a sieve or XRD process.

 

Dimensional adjustment is the change in grain size of the bed and it is critical to determining whether a site is changing from stable to erosional or depositional. It is a means by which change can be tracked before it becomes obvious by looking at other parameters.

 

Yes it is practical to measure against targets, just as it is for all the other indicators. Changes in substrate diameter through bulk analysis is part of all standard geomorphic monitoring programs and is required. 5cm changes in bed material are very significant in the process relationship of a stream. Will it get done? It is part of the monitoring plan and therefore should be done.

 

For Channel Stability and Erosion Potential.  Under the longitudinal parameter, what are "inter-pool and energy gradients" and what does it mean if they differ by more than 5%?

 

 

Inter-pool gradient is the line which connects the deepest part of pools in sequence with one another (i.e., pool 1 to pool 2, pool 2 to pool 3, etc.). The slope of the line that joins these depths is the inter-pool gradient and is a clear indicator of stability. Under equilibrium conditions that gradient is consistent; a change in that gradient (which is easily picked up through the long profile survey) indicates whether a site is tending toward erosional or depositional.

Energy gradients refer to the water surface elevation as flow moves through a reach under different flow conditions. It is also a slope, a line that joins points of water surface. As a general rule, pool energy gradients are flatter than riffles, and for the same riffle or pool, higher volume flows will generally have higher gradients than lower ones. This is not always the case and needs to be confirmed at the baseline data collection stage before implementation occurs.

 

If they differ under the same flow from existing to future then there is a corresponding change in the energy regime to the reach; steeper gradients result in erosional situations, gentler gradients result in depositional situations.

 

Under In-stream Aquatic Habitat, the composition and diversity of the benthic invertebrate community will provide a better indicator than the fish community.

 

Given the existing degraded conditions in the creek corridor, the immediate focus is reducing the impacts of

uncontrolled runoff (water quality and quantity) – see

other objectives and targets. As such, measurable parameters and targets for this indicator are to be developed in future subject to progress in achieving

water quality and quantity targets and mitigating existing

barriers.

The Riparian Habitat and Forest Cover indicators will be of limited value in this subwatershed, but should be retained for retrofits in other subwatersheds.

 

Forest Cover has been revised to Tree Canopy which is more reflective of an urban subwatershed (with the emphasis being on reducing runoff from frequent events as opposed to targeting large increases in forest cover).

Appendix A, Existing Conditions

The comments on the function of the Trail Road Landfill as a regional gull attractor are interesting (especially as they may have originated with me).  This implies, does it not, that there might be a benefit to spending some Ottawa River Strategy money on a gull management plan for Trail Road?  Similarly, should we be encouraging the NCC to better manage their goose population through passive measures, such as revegetation of grassed areas?

 

Agreed – there is a committee of NCC and City staff tasked with resolving such issues.

The greenspace identified as a potential daylighting site at Woodroffe and Tallwood is Urban Natural Feature 40 - Tallwood Woods.  The most valuable feature of this site is the mature maple grove in the center of the lot.  So daylighting the channel along the east side of the woodlot should not cause any big impacts.  In fact, it would probably increase the ecological value of the feature.  Sandy soils, though.

 

This location has been eliminated as a potential daylighting section due to the very limited length/improved function that could be achieved (for the cost) and the significant depth of the sewer in this location (resulting in a very wide, deep corridor that would take out much of the woods).

 

NCC

January 13, 2010

 

The NCC is willing to explore the possibilities for dry ponds and daylighting on its property as suggested in this report. Nothing in this report shall bind the NCC to accept or complete specific proposals. Any proposal is subject to the Federal Land Use and Design Approval process (pursuant to the National Capital Act), as well as an environmental assessment, if required under the Canadian Environmental Assessment Act.  The NCC’s primary concern is the environmental health of Pinecrest Creek and it would wish to ensure that any proposal improves the water regime and the environmental quality of the watercourse. The NCC would wish to ensure that the facilities are not located solely on NCC property.

Acknowledged.

However, the NCC is most interested by the possibilities for daylighting as these could represent a valuable opportunity to regenerate the landscape and improve areas for natural habitat, both aquatic and terrestrial. We encourage the City to fully explore the opportunities presented in the report and others that may have been overlooked.

Daylighting potential has been examined in the subsequent stages of work.

Open House #1

 

Public

December 4, 2009

The question I asked last night on the "Total E.coli Load" as a function of runoff volume could relate to treatment strategies, e.g., if a large proportion of E. coli, metal cations and inorganic anions appear in the "first flush" from a stream or outfall then one might envision a different treatment regime than one concerned with total runoff volume. As Darlene pointed out last night most rain falls being below 10 mm may make this concern academic.

However, if one has two rainfalls say of 5 mm each separated by N hours is the contamination of the run off for the second event diminished. Or put another way, how much run off is required to "flush" the creek of pollutants,

i.e., what is the relationship of water volume from a rainfall to pollutants flushing?

Most pollutants common to urban runoff demonstrate a “first flush” response, that is, the large majority of the pollutant load present is washed off in the early portion of a rainfall event. As a result, end-of-pipe facilities are typically designed to capture and treat only the “first flush” (since larger capacity would not result in significant improvements but would cost much more).

 

E.coli does not generally demonstrate a “first flush” response, however, typical SWM measures as have been considered in this study are capable of removing a large percentage of the E.coli load from stormwater.

Open House #1

 

Public

December 4, 2009

Another consideration for possible future treatment strategies is which areas of the Pinecrest Creek catchment area contribute most to the pollution of the creek? The map you showed last night indicated considerable geological and use variation in the catchment area. Might it be possible to treat stormwaters discharge from these areas before they run into the creek rather than trying to

manage the total water volume of the creek? It might be simpler to build at some selected locations small ponds if indeed certain areas are the major contributors to the water pollution. Also such small ponds might be used to

level the large increase of water discharge after a rain storm thereby decreasing damage to the creek structure. Even if there is not a difference in pollutants from various areas the creation of a number of local stormwater ponds rather than one large on may have a virtue.

Yes, the use of decentralized SWM facilities at various storm outfalls has been recommended as it is not feasible to treat all of the Pinecrest Creek outflow in one location at the confluence with the Ottawa River. Improving water quality before the runoff reaches the creek will also meet the objective of improving the health of the creek.

I am very encouraged with the draft report … good work!

However, I do have a major concern over three other issues that are, or should be part of this pilot project. The first is a concern I share with John on the need to involve schools in this project. I would even go further and

suggest that we should learn how the US cities got the citizens of their communities involved and do the same ASAP, i.e., before the next Open House. The second is the 2011 plan of implementation of study recommendations. Alex asked some good questions last night about cost /benefit analysis that are essential to be addressed when one goes to council seeking funding! The third is that there should be a considerable effort to make the public in the drainage area aware of the next open house. Ads in newspapers are good but, there are many other routes that should be used, e.g., community association involvement, asking area councillors for input and presence, ads in area stores, and articles in the local community newspapers.

Getting schools involved has been identified in the implementation plan.

 

The benefits achieved for the cost required have been identified to the extent possible at this level of study.

 

Public education and communication efforts have been identified as a key component of the implementation plan.

June 17, 2010 PAC mtg

Public

July 2, 2010

Darlene, I realize the meeting wasn't intended to outline the measurables that will eventually have to convince council for their support, but I worry about this - remember Cullen's concern at the public meeting. While you certainly should be looking for the best solutions at source, transmission and end of pipe, I was sort of hoping to see some mention of the cost/benefits when applied to various catchments - especially as it will affect Westboro Beach since this is what will likely be foremost on the minds of

councillors. Wavell of course comes to mind as probably the biggest threat to the beach and also the most costly to try and fix. So what to do, go for one of the more fixable catchments that will have a more modest cost and at least get something out of the study than can be held up as a model of accomplishment even though it might not have much impact on the beach but hopefully sets a positive direction for the future? I realize this wasn't the main purpose of the meeting, but I feel relating things to the beach might not be a bad mind-set as one works towards a conclusion.

The evaluation of the various retrofit scenarios and the following step of developing an implementation plan was aimed at addressing these kinds of concerns, i.e., what are the priorities to implement first and where? What benefits can be achieved and at what cost, etc.?

 

 

Queensway Terrace North Community Association

July 20, 2010

 

Is this all about Westboro Beach water quality? Is this about handling stormwater runoff only?

 

As part of this study, the water quality at Westboro Beach is only one of several objectives that we have for the study.  The objectives include:

  • Reduce flood risk to public health and safety and to property along the Pinecrest Creek corridor
  • Reduce erosion impacts in the Pinecrest Creek corridor that are detrimental to property, infrastructure and stream habitat
  • Re-establish a more natural hydrologic cycle for the Pinecrest Creek subwatershed
  • Improve water quality in Pinecrest Creek and the Ottawa River by reducing the impact of stormwater runoff
  • Reduce the impacts of stormwater runoff on Westboro Beach
  • Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor
  • Increase public awareness about stormwater management and public involvement

Yes, stormwater is our main concern for this study.

 

Queensway Terrace North Community Association

July 20, 2010

 

QTN Stormwater Management Today:

  • Britannia Heights portion of community has ditches that help.
  • Elmhurst and Frank Ryan Park are natural water management sites.
  • Severn Public School property a significant water management site.
  • Community well treed and grassed lawn area significant.

Yes, ditches are beneficial for stormwater management.  The City has a ditch infill policy where we try and maintain existing ditches where possible.

 

Recommendations for Consideration to Reduce Runoff from QTN:

1.         Repair and reset sewer drains.

2.         Review parks ability to handle more runoff.

3.         Rainbarrel purchase and installation program.

4.         Eavestrough runoff control program.

5.         Hard surface parking space on private property control program.

6.         Private property direct to storm sewer drainage control program.

7.         Severn Public School used as a model for water management.

8.         Stormwater drainage study.

These are great suggestions.  We will likely assess most of these as part of our study.  Perhaps you can provide more detail about Severn Public School and its role as a water management site and why it should be used as a model.

 

 

 

Recommendations for Consideration - Citywide:

1.            Retail/Commercial/Institutional parking lot runoff control program.

            - designated snow dump collection areas with absorbent material,

            - use of buried cisterns, more soft materials and trees.

2.         Living roof program for these buildings.

3.         Repair and reset sewer drains.

Excellent suggestions.  Point #1 is interesting.  We do plan to initiate a City-wide retrofit study, so these recommendations could be considered then.

 

 

 

Queensway Terrace North Community Association

July 20, 2010

 

Recommendations for Pinecrest Creek:

1.         Creation of settling ponds complete with native plants.

2.         More bends in creek to control erosion and flow rate.

3.         Create multiple parallel discharge points.

4.         Expand Mud Lake.

 

The first three recommendations are being assessed for their feasibility for the Pinecrest study area.  Other retrofit options include lot level strategies (pervious pavement, rain barrels, downspout re-direction, etc.), conveyance (grass swales, infiltration trenches, road narrowing, etc.) and end of pipe (stormwater management ponds).  Due to the ecological significance of Mud Lake, it would not be appropriate to use it to retain stormwater.

 

Steps 3 and 4 Report

Public

December 17, 2010

The JFSA report is a well done classical engineering study. It will, if implemented, improve many aspects of the problems currently plaguing the stormwater in Pinecrest Creek but, this will take decades to do if funding is

approved. However, I fear that the proposal for a stormwater pond near the Ottawa River is unrealistic and has little chance of ever being done. Even if this was done it would leave many stormwater outfalls dumping untreated into the Ottawa River. Further, the report does not address any aspects of the sources of E. coli in stormwaters and what might be done to immediately to reduce a given source.

 

The proposed retrofit plan includes a SWM facility to treat the runoff from the Wavell and Ardmore outfalls to the Ottawa River. NCC has identified specific conditions that would have to be met for a SWM facility to be considered on their property but have not eliminated this possibility.

While it is true that it will not be possible to provide end-of-pipe facilities at all outfall locations (due to the lack of space available), other measures (lot level and conveyance) will, as they are implemented over time, contribute to water quality improvements.

This study was not intended to differentiate the various sources of E.coli, which would require a separate, extensive monitoring study that was beyond the scope of this pilot study. While improving the quality of runoff will require a long-term effort given the size of the area that contributes and the overall cost of the various measures, this does not preclude efforts to prevent E.coli entering runoff in the first place, such as discouraging large concentrations of water fowl. Such efforts are under review by a joint committee of City and NCC staff.

Steps 3 and 4 Report

Public

December 17, 2010

My concern is Public Health as well as Ottawa River health. I propose that it is now an opportune time to submit my proposal for the phenotyping of E. coli in Pinecrest Creek and the outfalls.  The identification of E. coli source may allow "smart" short term actions to be undertaking to greatly reduce the E. coli pollution of waters flowing into the Ottawa River.  I trust I will have your support in undertaking a pilot DNA phenotyping study to address the Pinecrest Creek Westboro Beach outfalls.

While differentiating the various sources of E.coli might provide some additional insight, it would not necessarily assist in identifying different, less costly, or quicker solutions than have been identified through the retrofit study. Given the urban nature of the study area, it is a fair assumption that the sources are comprised of contributions from domestic pets, urban wildlife, water fowl and possibly human sources. Regardless of the proportional contributions, the measures to address these sources would not change (e.g., discouraging water fowl concentrations, existing by-laws, tracking and removal of cross-connections, etc.).

Open House #2

Public

 

December 5, 2010

I was less enthusiastic regarding the level of recognition of the critical need to significantly restore natural landscape values. It was good to highlight three areas where 'daylighting' was readily do-able in order to free significant portions of the creek from its entombment - but that was it. There was no discussion of widening natural vegetation buffers along the creek bank where they exist and of re-establishing them where they don't presently. No discussion either of 'naturalizing' freed creek sections; suggestions there was no room for re-establishing meanders (not correct in at least the Carling Ave - Richmond Road section), or the establishment of side pools and such. There's room for a lot more creativity to be injected into this.

The biggest problem, though, is that creek naturalization and day-lighting is NOT presently included in any of their solution alternatives. Ironically, it seems that restoration of the creek itself is treated largely as a motherhood 'wouldn't-it-be nice' objective within the watershed management concept. Remarkable, really, when the costs for undertaking such enhancements could be largely if not entirely absorbed within construction programs related to upgrading existing transportation facilities within the corridor.

Day-lighting (and naturalization) of significant sections of the creek must be an over-riding focus of all management alternatives, something that is factored into whatever happens in this watershed. Since this study represents the pilot project for subsequent urban subwatershed studies in this city it would be especially uninspiring if what is increasingly being seen across North America as a vital component of urban waterway management received only lip-service in the rehabilitation plan for our most urbanized watershed. If it isn't going to happen here, it won't happen anywhere.This creek has been in this unnatural transformed condition for less than 50 of its several thousand years of life. The creek itself, not just the watershed, has got tobe fixed for all sorts of economic, social and environmental reasons.

A key objective identified early in the study is to:  Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor (see Table 2.1 in Part B, Objectives and Targets). However, given the existing degraded conditions, it was determined that the immediate focus should be on mitigating the impacts of uncontrolled runoff (water quality and quantity) that will contribute to longer-term objectives and targets such as re-establishing and improving aquatic habitat.

 

With respect to daylighting, the scope of this study was limited to the very preliminary step of assessing physical feasibility. The preliminary work completed indicates considerable potential as indicated by the cross-sections prepared. Given the depth of the existing pipe, there may be some constraints related to necessary side sloping and the desire to avoid retaining walls or other hardened features. If/when daylighting is implemented in future, however, it is recognized that re-creating natural features and functions (to the extent possible) must be a key design outcome in keeping with the study objective noted above.

 

NCC:

Correspondence dated January 19, 2011

The NCC seeks clarity on whether all seven objectives are equal or whether some have greater priority, both in terms of policy and in investment. In particular, the NCC seeks clarity on whether the SWM quantity and quality objectives for Pinecrest Creek are considered to be equal to the water quality objectives for Westboro Beach.

The targets and objectives for the study have been developed to cover the broad range of factors that affect the overall “health” of both Pinecrest Creek and the receiving Ottawa River (i.e., in the vicinity and downstream of the creek confluence with the river). As such, there was no intent to rank or prioritize particular objectives and targets given that many are inter-related or complementary. For example, reducing runoff volumes will contribute to reduced erosion in the creek as well as contribute to improved water quality.

 

NCC

Prior to accepting any end of pipe solution on NCC property, the City must be able to demonstrate a proactive commitment to ensure that programs to address improvements at the lot level and conveyance level will be developed, implemented and maintained to ensure their ongoing performance.  Education and outreach programs appear to be very important in this regard.  It may be necessary to review how the Ontario Ministry of the Environment views lot level and conveyance measures in its approval process for end of pipe facilities to determine if this is a hindrance or deterrent to the adoption and implementation of such measures (i.e., are lot level and conveyance measures excluded from SWM pond sizing calculations) as well as if there are any potential solutions.

Acknowledged.

 

With respect to the Ministry of the Environment’s approval process, no hindrance is anticipated given that the proposed end-of-pipe facilities are retrofits (i.e., not greenfield applications) and further, part of an overall retrofit strategy that includes both lot level and conveyance measures. In other words, implementation of the proposed end-of-pipe facilities does not preclude the need for lot level and conveyance measures to achieve the various targets and objectives. For example, reducing runoff volumes can only be accomplished via lot level and conveyance measures.

 

NCC

The NCC is not currently able to agree in principle to the recommended retrofit scenario since it is too early to determine if such a very clear demonstration of a proactive commitment by the City to ensure that programs to address improvements at the lot level and conveyance level will be developed, implemented and continued.

Acknowledged.

 

NCC

Cost and ease of implementation must not be the only factors in choosing to site any facility or structure on NCC property. Alternatives, such as other public and private lands should also be examined.

Acknowledged. One of the end-of-pipe facilities proposed (EOP 3) has been located within a City park (Elmhurst Park).

 

NCC

The NCC will be writing a separate letter to discuss the potential cumulative effects of the proposed SWM ponds in addition to the effects of the proposed West Transitway extension from the SW Transitway (Pinecrest Creek corridor) to Pinecrest Road and the proposed extension of light rail from Bayview Station to Baseline Station. Such major interventions would require a comprehensive approach to the corridor including a landscape demonstration and naturalization plan as well as fisheries strategy.

Acknowledged.

 

NCC

Ownership and responsibility for drainage and infrastructure in several areas is not agreed between the City and the NCC. This should be clarified for this project and will be a requirement should larger projects occur on NCC property. For any new infrastructure, the City shall be responsible for its operation and maintenance, and any study should include the real estate costs associated with the use of lands not owned by the City.

Acknowledged.

 

The City would be wholly responsible for the operation and maintenance of any future end-of-pipe facilities implemented on NCC property.

 

NCC

We encourage the City to create an inventory of possible sites not just a list of preferred sites.  As part of any specific proposal, alternative sites should be examined, including other public lands, such as City of Ottawa and school board lands.

For this initial study, a total of 18 sites were screened down to the four sites recommended in the preferred Moderate retrofit scenario (see Table H1 in Appendix H). However, prior to proceeding with the implementation any end-of-pipe facility, further study would be required, including a more detailed examination of location alternatives (that was beyond the scope of this Master Plan level study).

 

NCC

We also encourage the City to continue its efforts in studying the urban tree cover and where improvements can be made to improve both the urban forest but also stormwater management.

Acknowledged.

 

NCC

The NCC encourages the City to develop and adopt SWM criteria such as those developed for the 2010 Pinecrest/Centrepointe SWM Criteria Study to ensure that development applications under the Ontario Planning Act create opportunities to achieve the objectives of the Steps 3 and 4 Study.

Stormwater management criteria for new/infill and re-development sites will be provided in the final study report (similar to those developed in the Pinecrest/Centrepointe SWM Criteria Study,  JFSA/JTBES, February 2010).

 

NCC

 

The NCC would like to ensure that if some or all the SWM measures were realized that the resulting water and sediment regime in Pinecrest Creek would be compatible with the Creek’s fluvial geomorphology and not cause or require major redesign efforts changes at the NCC’s cost.  The NCC would like the final study to comment if the Creek will have to be redesigned or further fluvial geomorphology rehabilitation measures and to what extent if some or all of the SWM measures are implemented.

This concern has been addressed in the final report (see section 3 in Part D of the main report and noted in Appendix K).

The Study does not address the effects of the multi-cell culverts in the Creek.  This merits mention in the report and where it may be potentially addressed.  There is potential for this to be addressed as part of the City’s transitway proposals.  We encourage your study to provide guidance should the Pinecrest Creek corridor be selected.

Multi-cell culverts and their impacts on Pinecrest Creek have been addressed in the 2007 JTBES/JFSA/LGL study for the NCC and again in the 2009 JTBES study for the City, and a protocol has been developed for use by the NCC so there is lots of information out there that both NCC and the City should be aware of. That said, this really was not part of the scope of this project and the impacts may need to be addressed fully again at the implementation study stage.

Ottawa River Parkway Corridor:  The study proposes a SWM facility on NCC property near the Ottawa River, which would, according to the study, assist in improving the water quality at Westboro Beach. In addition, any proposal for a SWM pond on NCC property near the Ottawa River must include a very thorough analysis of alternative sites, including those not on NCC property. Cost and ease of implementation must not be the only factors in choosing to site any facility on NCC property. Other requirements include:

·         Landscape and naturalization design must be to a very high standard and context sensitive

·         A cultural landscape analysis of effects may be required

·         An application for Federal Land Use and Design Approval must be submitted

·         NCC is concerned about the City’s (or any other public agency) ability to maintain any surface SWM ponds

·         Shoreline and stream enhancements will be necessary

All requirements acknowledged and to be incorporated in future implementation (EAs, detailed design, etc.) of any end-of-pipe facilities proposed to be located on NCC property.

 

NCC

 

Pinecrest Creek Corridor: The study proposes at least two SWM ponds within the corridor and potentially a third.

·         Landscape and naturalization design must be to a high standard and context sensitive.

·         An application for Federal Land Use and Design Approval must be submitted

·         NCC is concerned about the City’s (or any other public agency) ability to maintain any surface SWM ponds

All requirements acknowledged and to be incorporated in future implementation (EAs, detailed design, etc.) of any end-of-pipe facilities proposed to be located on NCC property.

Daylighting potential:  The NCC is very supportive in principle of daylighting opportunities where vegetation and views would not be affected and the opportunity to reintroduce an open air creek would support naturalization efforts.  Any daylighting project should respect natural channel design principles and include a landscaping and naturalization component.

All requirements acknowledged and to be incorporated should daylighting of the creek be implemented in future.

 

City of Ottawa SWM Section, comments dated March 9, 2011

 

3.1.1 Lot Level Private and Public Controls

Rain barrels and Cisterns

The proposed BMP’s are highly dependable on home owner’s long term participation. Can you please demonstrate with the help of some statistical data that would indicate the effectiveness of these practices in long-term?  (City of Ottawa launched in 2003 a Rain Barrel Program, 400 rain barrel units were sold, the addresses of the houses are still available in the City’s file.)

It is recognized that, beyond the Water Links effort referenced, there is minimal local knowledge and experience related to long-term participation on the part of individual homeowners. That experience and knowledge cannot be expanded without further efforts that were beyond the scope of this preliminary study, the main purpose of which was to provide a direction forward. This has been identified in the study’s implementation plan that recommends further initial steps to study and test the effectiveness of various lot level measures via pilot efforts as wells as the willingness of the public to participate, etc.

Porous and Permeable Pavement

Provide us with a few examples of implementation of those BMP’s used in equivalent to the City of Ottawa climate conditions.  (Cold winters, clogging conditions, frost heave…)

 

There has been considerable progress made in the application of these types of measures in cold climates in recent years. A recent literature review of this experience is provided here: http://www.sustainabletechnologies.ca/Portals/_Rainbow/Documents/SW_Infiltration%20Review_0809.pdf

It is also recognized that, prior to broader application, it will be essential to pilot these measures in Ottawa to gain local experience and this recommendation has been made in the study’s implementation plan.

 

City of Ottawa SWM Section

 

3.1.2 Conveyance Controls

Grass Swales, Infiltration Trenches

Implementation of infiltration trenches and swales are highly dependable on soil conditions.  Please demonstrate that these controls would function in the Pinecrest subwatershed since the Soil Map indicates mostly clay conditions.

Acknowledged. There are limitations to the application of some selected measures, and this will be accounted for accordingly via the preparation of design standards for such measures (as recommended in the study’s implementation plan).

3.1.2 Conveyance Controls

Street Narrowing

Street narrowing practice should be discussed with the Surface Operation in term of accessibility. (i.e. snow removal)

Agreed. The purpose of this study was to identify a proposed “suite” of measures that could achieve water quality improvements and runoff volume reductions.  Further study and consultation with City staff and the public will be required to identify specific locations in the study area where such measures can be feasibly implemented.

3.1.1.3           End of Pipe Facilities

Oil and Grit Separators

It is inappropriate to specify singular brands of OGS’s within this report. Either remove the singular reference or provide numerous more manufactures examples.

Maintenance aspects are also very important factors regarding the brand selection.

Agreed.

 

Agreed. Upon implementation of the proposed OGS’, the Stormwater Management Section will be consulted to ensure operation and maintenance requirements are addressed.

3.3. Stormwater Retrofit Scenarios

Has the consultant considered some other alternative options such as the use of City’s existing parklands?

 

One of the end-of-pipe facilities proposed (EOP 3, an oil grit separator) has been located within a City park (Elmhurst Park) and other park locations were considered but screened out. However, prior to the implementation of any end-of-pipe facility, alternative locations will be revisited again in more detail via the required Class EA process.

4.1 WindSlamm Modelling

Baird & Associate Ltd Report: Assessment of the Relative Impact of SWM Retrofit Alternatives Developed for The Pinecrest Creek Study

Can you please provide a comparison of results generated by the WinSlamm modeling and the Baird’s Assessment report (Pg 23- 5.0 Conclusions- 1st bullet)

 

The WinSLAMM modeling was used to generate E. coli loading from the study area (Pinecrest Creek and the Westboro outfalls) for the existing condition (no retrofits) and then adjusted to reflect the various retrofit scenarios. These resulting “pollutographs” were then input to the hydrodynamic model of the Ottawa River to model the effect of this E.coli loading at Westboro Beach (that could not be assessed by WinSLAMM). In other words, the WinSLAMM results represent the wet weather input to the river model, which then simulated the resulting E.coli counts at the beach.

5.2  SWMHYMO Models

Can you please provide a better explanation of Table 5.2 –Improvements in Producing a More Natural Hydrologic Cycle Within Pinecrest Creek, since this is maybe a “Key Selling Factor” in order to secure a Capital Budget.

 

Table 5.2 is a summary of the benefits of implementing SWM retrofit measures that reduce runoff volume. Since the study area is almost completely urbanized, existing runoff volumes are much higher and have impacted the creek over the last several decades. Aiming to reduce the runoff volume for relatively frequent rainfall events will result in a more “natural” hydrologic cycle than now exists.

5.4.1. Existing Hydraulic Conditions

Please clarify the 4th paragraph from the top “All proposed Scenarios produce lower peak flows than the existing conditions.”  This does not correspond to your statement quoted in the report Pinecrest/Centrepointe Stormwater Management Criteria – Page17, 5.1 Flood Control -Recommended SWM Criteria for Quantity Control for Flood Control Purposes on the Pinecrest Creek: “All future Development shall control their 1:100 year peak flow to 36 l/s/ha in order to maintain the existing1:100-year peak flows in the creek”.

 

This statement is based upon the implementation of the proposed retrofit end-of-pipe facilities that will provide some quantity/flood control if/when they are eventually implemented, in particular the facility at Baseline and Woodroffe (EOP 16). These retrofit facilities were not modeled during the preparation of the Pinecrest/Centrepointe Town Centre SWM Criteria Study (JFSA, JTBES, 2010) as they had not yet been identified (a task that was beyond the scope of that study).

The recommended retrofit end-of-pipe facility does not preclude the need for the quantity control criterion recommended for new/infill/redevelopment since it is uncertain when this facility will ultimately be built. In the interim, increased flood levels and risk resulting from new development must be prevented. However, if/when this facility is implemented in future, then the required quantity control criterion will revisited and potentially eliminated if it can be shown that the flood control benefits of the pond are adequate to compensate for the remainder of anticipated future development at that time.

Table 5.4.1.-Level of Service of the ORP pipe

Can you please clarify the meaning of the 2-year Level of Service of the Ottawa River Parkway culvert and the following interpretation in Table 5.4.1

 

This table indicates that, under existing conditions, peak flows beyond the two year event will not be fully conveyed by the piped section but will spill onto the Parkway. With the implementation of some retrofit quantity control storage, the level of service of the piped section can be improved.

7.0 Costing of Scenarios

We have noticed that the in-stream works were not a part of the retrofit‘s alternative costing analysis. Maintenance cost should be adjusted accordingly to confirm the values provided by the “TCAR study.”

 

The identification of potential future stream rehabilitation works was beyond the scope of this study. However, significant amounts of such works are not anticipated since the overall objective is to reduce erosion and maintain or improve stability. If/when major works proceed (e.g., proposed SWM facility at Baseline/Woodroffe), the need for any associated in-stream works would be identified at that time (and this requirement has been identified in the implementation plan).

 

COMMENTS RECEIVED FROM OPEN HOUSE No. 1                               DOCUMENT 12

 

Pinecrest Creek/Westboro Stormwater Management Retrofit Study

 

Open House and Information Session #1

December 3, 2009

Meeting Notes

 

Introduction

 

In the fall of 2009, the City of Ottawa launched the Pinecrest Creek/Westboro Stormwater Management Retrofit Study to identify a Retrofit Plan to improve stormwater management in Pinecrest Creek subwatershed and the adjacent Westboro area. The Retrofit Study is one of sixteen short-term projects included in the City’s Ottawa River Action Plan and is being conducted as a Master Plan under the Municipal Class Environmental Assessment process.

The Pinecrest Creek/Westboro area – like much of the core of the City – was developed before there was a requirement for municipalities to manage stormwater. For this reason, there are few facilities to treat stormwater in the study area. When it rains, stormwater collects on roofs, roads and parking lots, is transported in storm sewers and then is discharged into Pinecrest Creek or directly into the Ottawa River, carrying a host of pollutants with it. Uncontrolled stormwater leads to large volumes of runoff and high peak flows in streams. This affects water quality, exacerbates erosion, degrades fish habitat, threatens infrastructure, and contributes to beach closures at Westboro Beach.

 

When implemented, the Pinecrest Creek/Westboro Stormwater Management (SWM) Retrofit Strategy will help to:

·       improve water quality in Pinecrest Creek and the Ottawa River;

·       reduce flooding and erosion in the Creek;

·       improve the health of the Creek; and

·       reduce closures at Westboro Beach.

 

The City hosted the first Open House for the project on December 3, 2009 from 6:30 to 9:30 pm at the Ben Franklin Centre. The focus of the Open House was Existing Conditions in the study area and the objectives of the retrofit strategy. A display provided highlights of the work carried out to date, and the study team gave a presentation at 7:30 pm, which was followed by a question and answer session. In total, 14 people attended the Open House.

 

This meeting report was prepared by Joanna Kidd, meeting facilitator and is intended to reflect the major comments, suggestions and questions raised at the meeting and in Comment Forms. Any errors or omissions are the work of the author.

 

Presentation

 

Facilitator, Joanna Kidd from Kidd Consulting reviewed the agenda and introduced key members of the study team. Darlene Conway from the City of Ottawa provided an overview of the rationale for the SWM Retrofit Study. The absence of stormwater management facilities in the study area causes large volumes of stormwater run off and high peak flows to Pinecrest Creek. This degrades water quality, increases erosion, degrades fish habitat, threatens infrastructure and contributes to closures at Westboro Beach. Darlene reviewed the objectives of the SWM Retrofit Strategy which are to:[1]

1.      Reduce flood risk to public health and safety and to property along the Pinecrest Corridor.

2.      Reduce erosion impacts in the Pinecrest Creek corridor that are detrimental to property, infrastructure and stream habitat.

3.      Preserve and/or re-establish a more natural hydrologic cycle for the Pinecrest Creek subwatershed.

4.      Improve water quality in Pinecrest Creek and the Ottawa River by reducing the impact of stormwater runoff.

5.      Reduce the impacts of stormwater runoff on Westboro Beach.

6.      Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor.

7.      Increase public awareness about and involvement in stormwater management.

 

Darlene noted that the study will look for opportunities to retrofit stormwater management controls into the existing community, and will consider lot level, conveyance and end-of-pipe measures, along with stream rehabilitation. The study will define a range of retrofit scenarios, evaluate how well they meet the study objectives, and identify a Preferred Retrofit Plan for the Pinecrest Creek/Westboro area.

 

Heather Wilson from J.F. Sabourin & Associates provided information on the existing conditions in the study area and began with a virtual tour that followed Pinecrest Creek from its headwaters to its confluence with the Ottawa River and then along the Ottawa River downstream to Westboro Beach. Water quality in Pinecrest Creek is characteristic of urban watercourses, and levels of bacteria, chlorides, nutrients and heavy metals in the Creek frequently exceed the Provincial Water Quality Objectives. While water quality in the main section of the Ottawa River is good, water quality at Westboro Beach often exceeds the swimming guidelines. With respect to hydrology, she noted that Pinecrest Creek is the most urbanized subwatershed in the city, with 36% of the area covered by hard surfaces. Because of this, the Creek has a “flashy” response to rain: during a small rainfall event (about 10mm), flow velocities in the creek can triple in less than 15 minutes and erosive forces can increase by over 450%.

 

John Beebe from JTB Environmental Systems provided an overview of stream processes. The banks of the Creek are generally well-vegetated, but bank erosion and channel downcutting are common along many reaches, He provided a number of photographs of parts of the Creek where this was occurring, along with images of some of the stream restoration work that has been undertaken by the National Capital Commission.

 

Heather reviewed soils and hydrogeology, noting that soils tend to be thicker in the southern and western parts of the study area. With respect to terrestrial and aquatic ecology, she noted that forest cover makes up less than 3.8% of the study area. Aquatic habitat is degraded because of uncontrolled stormwater runoff. Fish surveys found four species in 1993, but only 1 in 2000. In terms of the built environment, the study area is drained by separated sewers, partially separated sewers and roadside ditches. There are only 8 stormwater management facilities in the study area, and there are 9 major stormwater outfalls in the Creek corridor and 10 along the Ottawa River.

 

Heather finished by outlining some of the inventory and database work that has been done to date. This includes the identification of infrastructure in the stream corridor, the assessment of flood risk, measurements of water levels and flows, and lot level surveys.

 

Joanna finished the presentation by outlining the next steps in the planning process which include:

·         Public Advisory Committee meeting (January 2010);

·         assessment of scenarios and development of a Preferred Retrofit Plan (January to April 2010);

·         Open House #2 and finalization of Retrofit Plan (Spring 2010);

·         30-day review period (Summer 2010); and

·         commencement of implementation of Retrofit Plan (2011).

 

Discussion

Treatment of Stormwater

In response to a question about whether the study would look at end-of-pipe treatment for stormwater as well as reduction in volume of stormwater runoff, the following points were made:

·         The study has multiple objectives;

·         A major objective is to reduce the amount of stormwater entering the Creek and slow down the release of stormwater into the Creek through use lot level, conveyance and end-of-pipe SWM measures;

·         The study will also be looking at ways of improving the quality of stormwater entering the Creek and Ottawa River through the use of stormwater settling ponds and technologies such as Dunker’s Flow Balancing; and

·         Other non-stormwater management actions, such as waterfowl management and increased riparian plantings will also contribute to improved water quality.

 

Measurable Outcomes

In response to questions about measurable targets relating to the Objectives, the following points were made:

·         Measurable targets for each Objective have been or will be set to track and measure progress;

·         Many of the targets are derived from objectives set in the Lower Rideau Watershed Strategy and the City’s stormwater management policies;

·         The targets include Provincial Water Quality Objectives for water quality;

·         There are no currently no Provincial standards for water quality at the outflow of Pinecrest Creek;

·         The modeling in the study will predict what the water quality will be at the mouth of Pinecrest Creek with the implementation of SWM Retrofit measures; and

·         Baird and Associates will insert these values into their Ottawa River model to predict the impact on Westboro Beach water quality.

 

Value for Money

In response to a question about the value of spending millions of dollars to gain 4 or 5 more days of swimming at Westboro Beach, the following points were made:

·         Improving water quality at Westboro Beach is only one of 7 Objectives;

·         Reducing the amount and timing of runoff into the Creek will address all of the objectives;

·         A more stable Creek will provide multiple benefits including the protection of infrastructure; and

·         A participant noted that an improved Pinecrest Creek Corridor could serve as an outdoor learning centre for schools in the area.

 

Potential for Daylighting the Creek

In response to a question about the potential for daylighting (opening up) parts of the Creek that are now buried, the following points were made:

·         The study is considering the potential for daylighting parts of Pinecrest Creek;

·         The Retrofit Plan will be a long-term plan, as it will take time to undo the impacts of decades of development; and

·         A participant shared an aerial photo from 1945 that showed the downstream reaches of the Creek were still in an open, meandering state at that time. A copy of the photo will be provided to the study team.

 

Potential for Stormwater Management Ponds

In response to a question about the potential for developing SWM ponds in the study area, the following points were made:

·         The study is looking at potential sites for retrofit SWM ponds;

·         Infill and redevelopment projects in the study area will also be required to implement SWM measures to meet the objectives of the Retrofit Plan; A participant suggested that land near the confluence of the Creek and the River that had been set aside to provide SWM for stormwater from outside the study area be used for SWM from Pinecrest Creek / Westboro. The study team will investigate the feasibility of this.

 

Ponding

A participant noted that there was sometimes ponding of water between Carling Avenue and the River. The study team will investigate.

 

Transport of Contaminants from Land

In response to a question about whether the study was investigating the first flush of contaminants from the land, the following points were made:

·         From a water quality perspective, the study is focusing on smaller, more frequent rainfall events (e.g., events in the order of less than 25mm of rainfall); and

·         It is generally accepted (based on numerous monitoring studies throughout North America) that these smaller events are responsible for most of the wash off of contaminants into water bodies.

 

Raising Public Awareness

A number of points were made about public awareness:

·         There is a need to educate upstream communities about downstream effects of pollution;

·         There is a need to build interest in the community in the study.

 

Notification of the Open House

In response to a question about how notification was made of the Open House, the following points were made;

·       Notification included ads in the Ottawa Citizen and local papers, invitations to e-mail lists, a presentation at a city-wide meeting of residents’ associations (CAFES) and material handed out at the recent Open Houses for the Ottawa River Action Plan; and

·       A participant suggested that more promotion should be done for future events.

 

Improving Forest Cover

In response to a question about whether the study is considering improving forest cover in the study area, the following points were made:

·         The study is looking at how urban tree canopy can be enhanced and the impacts of doing so;

·         Enhancing the tree canopy has multiple benefits; and

·         A participant noted that the National Capital Commission has held two tree plantings in the area and is interested in doing additional plantings.

 

Stormwater Management in New Developments

In response to a question as to whether the City would be requiring stormwater planning similar to what was done for recent development in the Centrepointe area, e.g. applying those requirements to other new developments, the following point was made:

The Retrofit Plan will provide SWM guidelines that new development will be required to meet (e.g., for water quality/quantity control and runoff volume reduction).

 

Other Feedback Received

Comment forms were available for participants to make additional comments. Completed forms were received from five people. Four of the five respondents live in the study area. Comments are provided below.

 

Information on Existing Conditions

·         Long-term compromised nature of the watershed (beginning in the 1920s).

·         Are familiar with some of the work carried out at Algonquin College.

 

Comments on the Objectives

·         The study should look at “bang for the buck”. For example, what impact would reducing downspout disconnections have on stream quality? What impact would a SWM pond at X location have? And what would be the costs?

·         An objective should be to liberate the creek (open it up).

·         The naturalization of bank vegetation should be emphasized.

·         The priority should be on improving water quality.

 

Other Comments on the Study

·         The existing SWM area at the mouth of the Creek should be utilized.

·         Would like to see significant improvements in water quality – should consider the use of SWM retention ponds.

·         Lack of public interest/awareness. More people will be interested once a dollar figure is better known and it ends up on our tax bill.

·         Cost of the project with minimal returns.

·         Accurately measuring the effectiveness of any retrofit.

·         What are other Ontario and North American cities doing concerning SWM?

COMMENTS RECEIVED FROM OPEN HOUSE No. 2                               DOCUMENT 13

 

Open House and Information Session #2

December 1, 2010

Meeting Notes

 

Introduction

In the fall of 2009, the City of Ottawa launched the Pinecrest Creek/Westboro Stormwater Management Retrofit Study to identify a Retrofit Plan to improve stormwater management in Pinecrest Creek subwatershed and the adjacent Westboro area. The Retrofit Study is one of sixteen short-term projects included in the City’s Ottawa River Action Plan and is being conducted as a Master Plan under the Municipal Class Environmental Assessment process.

 

The Pinecrest Creek/Westboro area – like much of the core of the City – was developed before there was a requirement for municipalities to manage stormwater. For this reason, there are few facilities to treat stormwater in the study area. When it rains, stormwater collects on roofs, roads and parking lots, is transported in storm sewers and then is discharged into Pinecrest Creek or directly into the Ottawa River, carrying a host of pollutants with it. Uncontrolled stormwater leads to large volumes of runoff and high peak flows in streams. This affects water quality, exacerbates erosion, degrades fish habitat, threatens infrastructure, and contributes to beach closures at Westboro Beach.

 

When implemented, the Pinecrest Creek/Westboro Stormwater Management (SWM) Retrofit Strategy will help to:

 

·       improve water quality in Pinecrest Creek and the Ottawa River

·       reduce flooding and erosion in the Creek

·       improve the health of the Creek and

·       reduce closures at Westboro Beach

 

The City hosted a second Open House for the project on December 1, 2010 from 6:30 to 9:30 pm at the Churchill Seniors Centre. The second Open House focused on how future stormwater management retrofit scenarios were identified and evaluated and what the proposed Stormwater Management Retrofit Strategy would mean for the creek and river, the community and the City.  A display provided highlights of the work carried out to date and City staff and members of the study team were on hand to answer questions. The study team gave a presentation at 7:30 p.m., which was followed by a question and answer session. In total, 8 people attended the Open House.

 

This meeting report was prepared by Joanna Kidd, meeting facilitator and is intended to reflect the major comments, suggestions and questions that were raised at the meeting, in Comment Forms and in emails received after the meeting. Any errors or omissions are the work of the author.

 

Presentation

Facilitator, Joanna Kidd from Kidd Consulting reviewed the agenda and introduced key members of the study team. Darlene Conway from the City of Ottawa provided an overview of the rationale for the SWM Retrofit Study. She noted that the absence of stormwater management facilities in the study area causes large volumes of stormwater to run off resulting in high peak flows to Pinecrest Creek. This degrades water quality, increases erosion, damages fish habitat, threatens infrastructure and contributes to closures at Westboro Beach. Darlene noted that the Pinecrest Creek/Westboro Stormwater Management Retrofit Study is one of the projects included in the City’s Ottawa River Action Plan, and is a pilot project for a City-wide strategy to retrofit stormwater management measures.

 

Heather Wilson from J.F. Sabourin & Associates began by reviewing the impacts of uncontrolled stormwater runoff and the seven objectives of the study. These are to:[1]

1.      Reduce flood risk to public health and safety and to property along the Pinecrest Corridor.

2.      Reduce erosion impacts in the Pinecrest Creek corridor that are detrimental to property, infrastructure and stream habitat.

3.      Preserve and/or re-establish a more natural hydrologic cycle for the Pinecrest Creek subwatershed.

4.      Improve water quality in Pinecrest Creek and the Ottawa River by reducing the impact of stormwater runoff.

5.      Reduce the impacts of stormwater runoff on Westboro Beach.

6.      Protect, enhance or rehabilitate natural features and functions along the Pinecrest Creek corridor.

7.      Increase public awareness about and involvement in stormwater management.

 

She then reviewed how the study was carried out.

Step 1: Background Information and Inventory

In Step 1, the study team collected background information on existing conditions in the study area. This included information on soils, land uses, development types and existing stormwater management measures.

 

Step 2: Develop Stormwater Management Objectives and Targets

 

In Step 2, objectives were developed for the study and numerical targets were set for the objectives.

 

Step 3: Identify Potential Stormwater Management Measures and Scenarios

In Step 3, the study team pre-screened a long list of potential stormwater management measures for suitability and effectiveness in the study area. Any that were not cost-effective, or which had significant negative environmental or social impacts were eliminated from consideration. The remaining measures were used in the development of future scenarios. The stormwater management measures on the “short list” included “at source” measures (downspout disconnection or redirection, rainbarrels and rain gardens), “conveyance” measures (infiltration trenches and street narrowing), and “end-of-pipe” measures (oil and grit separators and stormwater management ponds).  The study team then developed four scenarios that represent a range of level of effort in retrofitting stormwater management measures. These were compared with the existing condition. The future scenarios were:

 

 

 

 

 

 

Step 4: Evaluate the Scenarios against Key Factors

In this Step, the study team used modelling to determine the relative effectiveness of the scenarios in removing the key pollutants (Total Suspended Solids, Total Phosphorus and E. coli bacteria) and reducing the rate of runoff. Modelling was also used to determine the reduction of E. coli at Westboro Beach. The scenarios were evaluated against the following criteria:

 

Water quality                          Aquatic habitat

Runoff impacts at beach         Open space/parks

Flood risk                                Terrestrial systems   

Erosion impacts                       Natural features

Hydrologic cycle

 

Step 5: Select Preferred Retrofit Scenario

Heather noted that the “Moderate Implementation” scenario was selected as the preferred Retrofit Scenario because it:

 

 

Heather also noted that the much higher cost for the Highest Practical Implementation scenarios does not provide a proportional increase in benefits relative to the Moderate Implementation scenario.

She reviewed the elements of the preferred Retrofit Plan, which includes the installation or construction of:

 

·         Daylighting

·         Heather noted that there are three locations in which there is sufficient physical space to daylight parts of the now-buried sections of Pinecrest Creek that begin just south of Carling Avenue. There are a number of constraints on these areas, and additional work is required to assess these constraints.

 

·         Next Steps

·         Heather finished her presentation with the next steps which include:

 

December 2010 - February 2011

 

Spring 2011

 

Fall 2011

·         Begin implementation of Retrofit Plan

 

Discussion

·         Ditches and Swales

·         On Tweedsmuir Avenue, the City is replacing roadside ditches with storm sewers, which flies in the face of the need to manage stormwater better.

·         The City of Ottawa does have a Ditch Infill policy that discourages ditch infilling and/or requires that if ditches are to be replaced that the new drainage system provide the equivalent benefits of ditches.

·         The Pinecrest Creek/Westboro Stormwater Management Retrofit Study will help demonstrate the value of retaining roadside ditches and swales.

 

·         Road Narrowing

·         The community was pushing for road narrowing on Tweedsmuir for traffic calming reasons, but the City wanted it wider.

·         Some street narrowing designs can be a problem for cyclists.

·         Street narrowing can be done on a block-by-block basis and needs to balance many issues.

 

·         End-of Pipe Treatment

·         If the NCC does not allow stormwater management ponds on its property, the benefits of the Moderate Implementation scenario will be reduced.

·         There may be other opportunities for retrofitting end-of-pipe facilities, such as McKellar Park.

·         The study team will document all potential locations for end-of-pipe facilities.

·         There may be community support for putting oil and grit separators (for example) underneath parks.

·         It is good that the City is embracing a range of stormwater management measures and is not planning to rely only on large stormwater management ponds.

 

·         Terrestrial Habitat

·         The City should take an aggressive approach to restoring habitats in the Pinecrest corridor, including naturalized buffers.

·         This should include not allowing more structures in the corridor.

 

·         Daylighting

·         Daylighting the creek is very important and the City should be more optimistic about the potential to daylight.

 

·         Evaluation Criteria

·         Improving the natural environment should be the overriding objective of the study.

 

·         Policy Coherence

·         The City should develop a coherent policy for stormwater management that is applied to all development proposals. This needs to be communicated to all departments, including the Building Department.

 

·         Incentives

·         The City should consider providing incentives for high cost actions such as the replacement of impervious surfaces on driveways with pervious surfaces.

 

·         Preferred Retrofit Scenario

·         A number of participants noted that they supported the general direction and the selection of the Moderate Implementation scenario.

·         The Westboro Community Association will promote the use of rainbarrels to its members.

 

·         Implementation

·         It is vital that implementation of the strategy takes place.

 

Other Feedback Received

·         Comment forms were made available at the Open House for participants to make additional comments. Completed forms were received from two people and email comments were received from three others. The comments are summarized below.

 

·         Support

All five people indicated their general support for the proposed Retrofit Plan. Specifically, support was expressed for:

 

·         The general approach being taken for retrofitting stormwater management measures;

·         Not relying too much on end-of-pipe treatment;

·         Placing a lot of emphasis on lot level controls on private land;

·         The use of rainbarrels, downspout re-direction, rain gardens and use of pervious products on driveways when they are re-done;

·         Rehabilitation of the creek corridor, which is important for the quality of human and natural life in the watershed; and

·         Identifying where the creek can be daylighted.

 

·         Concerns

·         Concerns raised included the following:

·         The lack of consideration of restoration of the natural landscape in the study (e.g., widening existing natural vegetation buffers along the creek, re-establishing vegetation where it doesn’t presently exist, tree-planting, and naturalizing daylighted creek sections);

·         That creek naturalization and daylighting are not an overriding focus, and are not included in any of the alternative scenarios being considered;

·         Locating a stormwater management pond near the Ottawa River is unrealistic;

·         The study does not address any aspects of the sources of E. coli in stormwater and what could be done to reduce a given source immediately; and

·         Concern about impact of rainbarrels on moisture levels around the foundations of houses.

 

·         Suggestions

·         A number of suggestions were made including:

·         Replace the term “daylighting” with “liberating” to convey the concept of restoration of form and function;

·         Support a DNA phenotyping study to address sources of E. coli in the Pinecrest Creek and Westboro Beach outfalls; and

·         Review the rainfall data for 2010 to look at correlation with E. coli levels at Westboro Beach (i.e., was the low number of days of beach closures related to a low number of rainfall events).