1. Carp river restoration plan Third party review

EXAMEN PAR UN TIERS DU PLAN DE REmise en état DE LA RIVIÈRE CARP

Committee recommendations as amended

That Council:

1. Approve the Third Party Review - Carp River Restoration Plan, March 2009, and the Conclusions and Recommendations in Phase 1, Section 8 (pages 79-82) and Phase 2, Section 9 (pages 123-126) prepared by Greenland International Consulting Ltd. (Document 1) except the timing for the restoration plan which is dealt with in Recommendation #10;

2. Authorize staff to respond per the Disposition to the Minister of the Environment’s order under the Environmental Assessment Act dated July 21, 2008 based on the Third Party Review and other information in this report;

3. Authorize staff to respond to the Minister’s request to consider climate change adaptation as outlined in the Climate Change section of this report;

4. Direct that all development application approvals in Kanata West and the portion of Fernbank tributary to the Carp accommodate a per hectare share of the 85,600 m³ deficit volume until data is available to confirm the model;

5. Direct that at least a quarter of the deficit volume be provided through a permanent widening of the corridor and that the locations for widening be determined in the final design of the restoration plan;

6. Authorize staff to circulate an official plan amendment (generally in form of Document 2) providing a site-specific policy for the Carp River Restoration corridor and schedule a public meeting;

7. Direct that the City develop stormwater runoff targets for development once the model is validated, in consultation with the Kanata West Owners Group, and, in the interim, apply the 100-120 cubic metres storage requirement recommendation by Greenland, the development of the targets to be at the cost of the Kanata West Owners Group, such work to be done by the City’s consultant to the satisfaction of the City.

8. Approve a budget of $75,000 to retain Greenland International as the model keeper through 2009 and waive the provisions of the Notice By-law with respect to this budget amendment;

9. Direct that the first phase of the Carp River Restoration be tendered within 24 months of approval of the Class Environmental Assessments for the Carp River, Poole Creek and Feedmill Creek Restoration, Kanata West Transportation Master Plan and Kanata West Master Servicing Plan;

10. Direct that the Implementation Plan for Kanata West be revised to incorporate the recommended changes in Document 3 related to measures to protect flood capacity and water quality in the Carp River;

11. Direct staff to insert conditions in the Community Design Plan for Fernbank that require that peak flows not exceed existing conditions and increases in run-off volume do not exceed an additional 40,000m3 above existing conditions for the 100 year event;

12. Authorize staff to proceed with development applications within Kanata West as outlined in this report, under the conditions that:

a) No development within the flood plain shall be approved until the Environmental Assessment for the Carp River, Poole Creek and Feedmill Creek Restoration Plan is approved;

b) Development outside the flood plain may be approved subject to review of each application on a case-by-case basis in consultation with MOE to determine whether the application may proceed prior to the resolution of the seven contested EA projects.

13. Approve that the following development applications be able to obtain any necessary certificates of approval at this point without the final resolution of the Carp River Restoration Environmental Assessment and related matters having occurred:

a) Westwood Phase 3 (15-00-SD22 - Phase 3)

b) Broughton Subdivision (D07-16-04-0020)

c) Kinghaven Subdivision (D07-16-05-0020)

d) Hidden Lakes Subdivision Phase 3A (OLV2001-0012)

e) Rivington Subdivision (D07-16-07-0029)

f) Huntley Medical Centre (D07-12-08-0054)

g) Huntley Centennial Public School (D07-12-08-0036)

h) CMHC 20 Cedarow Court (D07-12-09-0060)

14. Support the Ministry of the Environment issuing the necessary approvals for the construction of the Interim Pond for Fairwinds South, Phase 5 and the stormwater sewer leading to such pond.

Recommandations MODIFIÉEs DU Comité

Que le Conseil :

1. approuve le rapport de Greenland International Consulting Ltd. sur l’examen par un tiers du Plan de remise en état de la rivière Carp (Third Party Review – Carp River Restoration Plan, mars 2009), notamment les conclusions et recommandations présentées au chapitre « Phase 1 » (section 8, pages 79-82) et « Phase 2 » (section 9, pages 123-126) (voir document 1) sauf le choix du moment pour le plan de restauration qui est traité dans la recommandation #10;

2. autorise le personnel à faire le nécessaire relativement aux recommandations et autres données du rapport sur l’examen par un tiers, et ce, conformément aux dispositions de la Loi sur les évaluations environnementales et du décret du ministère de l’environnement (21 juillet 2008);

3. autorise le personnel à procéder en vue de répondre à la demande du ministère de tenir compte de l’adaptation aux changements climatiques, selon les recommandations du rapport compris dans la section Changements climatiques;

4. fasse en sorte que, d’ici à ce que les données viennent confirmer le modèle, l’ensemble des plans d’aménagement dans Kanata Ouest et la portion de Fernbank tributaire de la rivière Carp soient approuvés moyennant une contribution au volume théorique déficitaire de 85 600 m³ proportionnelle aux hectares concernés;

5. fasse en sorte qu'au moins un quart du volume déficitaire soit prévu par un élargissement permanent du couloir et que les endroits pour cet élargissement soit déterminé dans le dessin final du plan de restauration;

6. autorise le personnel à rendre publiques les modifications au plan officiel (correspondant grosso modo au document 2), y compris une politique propre au couloir de remise en état de la rivière Carp et un calendrier des assemblées publiques;

7. donne instruction à la Ville d’établir des cibles d’écoulement des eaux pluviales à mettre en œuvre une fois que le modèle aura été validé, de concert avec le Kanata West Owners Group (groupe des propriétaires de Kanata-Ouest), et que, d’ici là, il applique le critère d’entreposage de 100 à 120 mètres cubes recommandé par Greenland, et que l’établissement des cibles soit à la charge du Kanata West Owners Group, les travaux devant être effectués par l’expert-conseil de la Ville à la satisfaction de cette dernière.

8. approuve un budget de 75 000 $ pour retenir Greenland International comme le surveillant du modèle jusqu’à la fin de l’année 2009 et que les provisions du Règlement intérieur de Préavis soit dérogé en ce qui concerne cet amendement budgétaire;

9. fasse en sorte (à moins qu’un autre fait déclenche ce processus) qu’on demande les soumissions relatives au premier volet du plan de remise en état de la rivière Carp dans un délai de 24 mois suivant l’approbation des évaluations environnementales de portée générale des plans de remise en état de la rivière Carp, du ruisseau Poole et du ruisseau Feedmill, du Plan directeur des transports de Kanata Ouest et du Plan directeur de viabilisation de Kanata Ouest;

10. prévoie une révision du plan de mise en œuvre des projets dans Kanata Ouest de façon à incorporer les modifications recommandées (document 3) relativement aux paramètres des projets et aux autres mesures visant à préserver la capacité à résister aux crues et la qualité de l’eau de la rivière Carp;

11. demande au personnel d’inclure au plan de conception communautaire de Fernbank des conditions stipulant que les débits de pointe ne doivent pas dépasser les débits actuels et que le volume de ruissellement ne dépasse pas 40 000 m³ de plus que celui des conditions existantes en prévision de pluies centennales;

12. autorise le personnel à mettre en œuvre les plans d’aménagement de Kanata Ouest décrits dans le présent rapport, à condition que :

a) aucun plan touchant aux plaines inondables ne soit mis à exécution avant l’approbation de l’évaluation environnementale de portée générale des plans de remise en état de la rivière Carp, du ruisseau Poole et du ruisseau Feedmill;

b) les plans d’aménagement à l’extérieur des plaines inondables soient approuvés sous réserve d’un examen individuel de chaque demande, en consultation avec le ministère de l’Environnement, pour déterminer si une autorisation est possible avant le règlement des différends relatifs aux sept projets d’évaluation environnementale.

13. accepte que les demandes d’aménagement énumérées ci-dessous puissent donner lieu à l’obtention des certificats d’approbation dès maintenant, sans que l’évaluation environnementale du projet de restauration de la rivière Carp et les questions connexes n’aient été finalisées :

a) Westwood, phase 3 (15-00-SD22 - Phase 3)

b) Lotissement de Broughton (D07-16-04-0020)

c) Lotissement de Kinghaven (D07-16-05-0020)

d) Lotissement de Hidden Lakes, phase 3A (OLV2001-0012)

e) Lotissement de Rivington (D07-16-07-0029)

f) Centre médical de Huntley (D07-12-08-0054)

g) École publique Centennial de Huntley (D07-12-08-0036)

h) SCHL, 20, cour Cedarow (D07-12-09-0060)

14. accepte que le ministère de l’Environnement donne les approbations nécessaires pour l’aménagement du bassin provisoire du lotissement de Fairwinds South, phase 5, ainsi que de l’égout pluvial menant à ce bassin.

Documentation

1. Deputy City Manager’s report, Infrastructure Services and Community Sustainability dated 16 April 2009 (ACS2009-ICS-CSS-0005).

2. Extract of Draft Minute, 11 May 2009.

Report to/Rapport au :

Planning and Environment Committee

Comité de l'urbanisme et de l'environnement

and Council / et au Conseil

4 May 2009 / le 4 mai 2009

Submitted by/Soumis par : Rob Mackay, Manager/Gestionnaire

Strategic Projects/projets stratégiques

Contact Person/Personne-ressource : Carol Christensen, Manager/Gestionnaire, Environmental Sustainability/Durabilité de l’environnement, Community and Sustainability Services/

Services de viabilité et des collectivités

(613) 580-2424 x21610, Carol.Christensen@ottawa.ca

Kanata North (4), West Carleton-March (5), Stittsville-Kanata West (6), Rideau-Goulbourn (21), Kanata South (23)

Ref N°: ACS2009-ICS-CSS-0005

SUBJECT:	Carp river restoration plan Third party review

OBJET :	EXAMEN PAR UN TIERS DU PLAN DE REmise en état DE LA RIVIÈRE CARP

REPORT RECOMMENDATIONS:

That Planning and Environment Committee recommend that Council:

1. Approve the Third Party Review - Carp River Restoration Plan, March 2009, and the Conclusions and Recommendations in Phase 1, Section 8 (pages 79-82) and Phase 2, Section 9 (pages 123-126) prepared by Greenland International Consulting Ltd. (Document 1) except the timing for the restoration plan which is dealt with in Recommendation #10;

2. Authorize staff to respond per the Disposition to the Minister of the Environment’s order under the Environmental Assessment Act dated July 21, 2008 based on the Third Party Review and other information in this report;

3. Authorize staff to respond to the Minister’s request to consider climate change adaptation as outlined in the Climate Change section of this report;

4. Direct that all development application approvals in Kanata West and the portion of Fernbank tributary to the Carp accommodate a per hectare share of the 85,600 m³deficit volume until data is available to confirm the model;

6. Authorize staff to circulate an official plan amendment (generally in form of Document 2) providing a site-specific policy for the Carp River Restoration corridor and schedule a public meeting;

7. Approve a budget of $73,000 to develop maximum stormwater runoff per hectare targets to be applied to all development applications in Kanata West and Fernbank and waive the provisions of the Notice By-law with respect to this budget amendment;

8. Direct that the City retain Greenland to provide the target levels of stormwater runoff from development with the cost of such services being reimbursed to the City from the Kanata West Landowner Group;

9. Approve a budget of $75,000 to retain Greenland International as the model keeper through 2009 and waive the provisions of the Notice By-law with respect to this budget amendment;

10. Direct that the first phase of the Carp River Restoration be tendered within 24 months of approval of the Class Environmental Assessments for the Carp River, Poole Creek and Feedmill Creek Restoration, Kanata West Transportation Master Plan and Kanata West Master Servicing Plan;

11. Direct that the Implementation Plan for Kanata West be revised to incorporate the recommended changes in Document 3 related to measures to protect flood capacity and water quality in the Carp River;

12. Direct staff to insert conditions in the Community Design Plan for Fernbank that require that peak flows not exceed existing conditions and increases in run-off volume do not exceed an additional 40,000m³ above existing conditions for the 100‑year event;

13. Authorize staff to proceed with development applications within Kanata West as outlined in this report, under the conditions that:

a) No development within the flood plain shall be approved until the Environmental Assessment for the Carp River, Poole Creek and Feedmill Creek Restoration Plan is approved;

RECOMMANDATIONS DU RAPPORT

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

7. alloue un budget de 73 000 $ à la maximisation des cibles de gestion des eaux pluviales par hectare pour tous les plans d’aménagement dans Kanata Ouest et Fernbank, et suspende les dispositions du règlement sur l’affichage relativement aux modifications du présent budget;

8. approuve que la Ville retienne Greenland comme intervenant pour établir les objectifs de gestion des eaux pluviales et que le coût de définition des objectifs soient remboursés à la Ville par KWOG;

9. approuve un budget de 75 000 $ pour retenir Greenland International comme le surveillant du modèle jusqu’à la fin de l’année 2009 et que les provisions du Règlement intérieur de Préavis soit dérogé en ce qui concerne cet amendement budgétaire;

10. fasse en sorte (à moins qu’un autre fait déclenche ce processus) qu’on demande les soumissions relatives au premier volet du plan de remise en état de la rivière Carp dans un délai de 24 mois suivant l’approbation des évaluations environnementales de portée générale des plans de remise en état de la rivière Carp, du ruisseau Poole et du ruisseau Feedmill, du Plan directeur des transports de Kanata Ouest et du Plan directeur de viabilisation de Kanata Ouest;

11. prévoie une révision du plan de mise en œuvre des projets dans Kanata Ouest de façon à incorporer les modifications recommandées (document 3) relativement aux paramètres des projets et aux autres mesures visant à préserver la capacité à résister aux crues et la qualité de l’eau de la rivière Carp;

12. demande au personnel d’inclure au plan de conception communautaire de Fernbank des conditions stipulant que les débits de pointe ne doivent pas dépasser les débits actuels et que le volume de ruissellement ne dépasse pas 40 000 m³ de plus que celui des conditions existantes en prévision de pluies centennales;

13. autorise le personnel à mettre en œuvre les plans d’aménagement de Kanata Ouest décrits dans le présent rapport, à condition que :

b) aucun plan touchant aux plaines inondables ne soit mis à exécution avant l’approbation de l’évaluation environnementale de portée générale des plans de remise en état de la rivière Carp, du ruisseau Poole et du ruisseau Feedmill;

c) les plans d’aménagement à l’extérieur des plaines inondables soient approuvés sous réserve d’un examen individuel de chaque demande, en consultation avec le ministère de l’Environnement, pour déterminer si une autorisation est possible avant le règlement des différends relatifs aux sept projets d’évaluation environnementale.

EXECUTIVE SUMMARY

Assumptions and Analysis:

Greenland International Consulting Ltd. was contracted to provide an objective Third Party Review (TPR) opinion on the work that has been completed to date on the Carp River Restoration Plan and related projects. The review process included input from the public and various stakeholders. A Project Advisory Committee was struck to provide input during the process and comment on drafts of the report.

Modelling

The model of the upper Carp subwatershed, that includes six different computer models, was evaluated in detail during the TPR. The models, although complex and recently requiring adjustments, were found to be sufficient to guide the planning decisions made in the Class Environmental Assessments (EA).

The previously missing hydrographs have been accounted for in the updated HEC-RAS (hydraulic) model. Infiltration and runoff parameters were within acceptable ranges for the hydrologic models, except in the upper rural catchments where data does not exist to confirm the appropriate local parameters. Greenland dealt with this uncertainty by creating a worst-case scenario using the maximum expected runoff from the upper rural catchments. The increased flows could exceed floodplain storage by 85,600 cubic metres, about 12 per cent of the flows to the Carp from this drainage basin. Greenland suggested that this potential deficit volume could be accounted for in a variety of practical ways, including source controls and storage enhancements. Greenland and staff recommend that this deficit volume be accounted for on a per hectare basis in each development approval in Kanata and Fernbank until monitoring data is available to confirm the model.

In order to minimize the possibility of undetected modeling errors, Greenland and staff recommend that one party (the model overseer) become responsible for documenting any changes to the models and circulating them to consultants working on various projects. Further, targets (expressed as maximum stormwater runoff per hectare) for stormwater management should be set to guide individual development applications, rather than re-running the model in all cases. Although City staff will assume this role in the long term, it is recommended that a budget of $75,000 be approved for the role of overseer by Greenland until year-end 2009 and $73,000 for the development of targets. Staff recommends that the cost of target development be recovered from KWOG.

Greenland investigated the Auditor General’s concern about underestimated runoff volumes. A review of the calibration methodology determined that a 0.33-metre datum shift at the Palladium Drive gauge coupled with the additional runoff volume being re-accounted for in the newly adjusted hydrologic model explains most of the missing flood volume in the Auditor General’s report.

Flow monitors have been installed in three locations: at Richardson Side Road and on Maple Grove at the Carp River and at the Poole Creek crossing. Greenland confirmed that the selected locations will eventually provide data to resolve the routing of the tributaries and complete the validation of the models.

Worst Case Scenario

Data does not exist to confirm the appropriate infiltration and runoff parameters for the upper rural catchments (e.g. headwaters of Poole Creek). Greenland dealt with this uncertainty by creating a “worst case” scenario, setting the parameters at their maximum reasonable value. Modelling of this “worst case” scenario found that the increased flows could exceed storage by 85,600 cubic metres. Greenland and staff recommend that all future development applications should account for a per hectare share of this deficit volume, until data are available to confirm the correct parameters for the upper rural catchments. Staff further recommends that a quarter of the deficit volume be provided through a permanent widening of the corridor. This will provide ongoing flexibility in the restoration for both the deficit volume and climate change.

Carp River Restoration

The TPR found that the overall flood storage capacity will increase in the Carp River corridor with the proposed restoration plan. The low flow channel design will increase velocity, improve sediment transport and reduce the potential for ice jamming. Furthermore, the flood levels at the Highway 417 bridge will not increase with the proposed restoration plan.

The proposed Carp Restoration Plan will take a degraded river and improve its sediment transport and balance. As well, its water quality and its habitat function will be improved by planting vegetation along the riverbanks, and adding features such as fish habitat pools and wetlands.

Greenland recommended a development cap of 65 per cent of the development area of Kanata West and Fernbank before requiring the Restoration. To minimize investments in interim facilities, staff is recommending that the initial phase of the restoration be tendered for construction within 24 months of the approval of the 22 EA projects for Kanata West.

Staff recommends that the Implementation Plan for Kanata West be revised to incorporate other recommendations from the TPR related to measures to protect flood capacity and water quality in the Carp River.

Once the Restoration Plan has been completed, there will be as-constructed elevations that can be used to update the HEC-RAS model in order to establish new flood plain mapping for the corridor.

Fernbank

According to Greenland, the Fernbank lands in the developed condition do not need to be incorporated in the models now. Development in the Fernbank area can be approved subject to approval conditions in the Community Design Plan. These conditions will require that peak flows not exceed existing conditions and increases in run-off volume do not exceed an additional 40,000m³ above existing conditions for the 100-year event.

Impact on Class EA projects

The outcome from the corrected models does not affect the recommendations of the environmental assessments. Specifically, neither the seven class EA projects that have been subject to Part II order requests or the other 15 approved Class EA projects are impacted at the planning decision/EA level by the model changes.

Climate Change

The accommodation of the worst-case volume provides a cushion of flexibility with regards to the impacts of climate change. Any at-source control measures and corridor width increases put in place to accommodate this deficit volume will continue to provide flexibility over the long term. The September 2004 storm used in past studies to calibrate the models was greater than a 100-year event, and it did not create flood levels that exceeded the present flood lines at any of the bridges in this reach of the Carp River.

Development Approvals in Kanata West

In May 2008 Council adopted a motion that set conditions for development approval of lands outside the floodplain in Kanata West. Council approval of the Third Party Review would satisfy Council’s motion and authorize staff to proceed with development applications in Kanata West outside the floodplain if it is decided in consultation with the local office of MOE that the application is not dependent on any of the seven contested Class EA projects.

No development on lands within the flood plain will be approved, until the Carp Restoration Environmental Assessment has been approved and other conditions in the proposed Official Plan amendment for the Carp River Restoration have been met.

Requirements of the Minister’s Order of 21 July 2008

The Minister’s Order requires that the City and KWOG report back to the Ottawa District Office and the Environmental Assessment Approval Branch of MOE on a number of matters based on the results of the Third Party Review. Staff and KWOG will revise and update the Carp River Restoration Project, Master Servicing Study, and Transportation Master Plan to include the results of the Third Party Review as well as any other changes resulting from the Minister’s conditions and all agency and public correspondence related to the Projects. A Notice of Completion will be issued, complete with a 30-day public comment period, and all the provisions of the comment period, including provisions for Part II Order requests.

Financial Implications:

If Council approves this report’s Recommendations 7 and 9, an additional $148,00 will be required.

The cost to develop maximum stormwater runoff targets for developments in Kanata West and Fernbank, estimated at $73,000 including contingency, will be funded from Internal Order # 903940 - Carp River Restoration. There is a possibility that approximately 95 per cent of this cost will be recovered from KWOG pursuant to staff’s recommendation.

The retention of a “model keeper” has been estimated at $75,000 and funds are available in the 2009 Operating Budget in Cost Centre 112737.

The City’s 30 per cent share of the Carp River restoration has been revised to $2.6M. Council approved $390,000 in the 2007 budget for the City’s contribution to the first year of restoration/construction under Internal Order 903940 - Carp River Restoration. The balance will be requested as part of future years’ Capital Budgets. With the approval of Recommendation 10, the timeline will commence in 2011.

Public Consultation/Input:

The report of the Third Party Review was placed on the City’s web site, advertised in The Citizen and Le Droit newspapers, a copy provided to the Auditor General and notice provided by individual e-mails to everyone who made a Part II Order request or who provided comment on the Terms of Reference. A technical briefing was conducted on 9 April 2009.

Ten submissions were received. The comments and responses have been summarized in a table attached as Document 8.

RÉSUMÉ

Hypothèses et analyse :

La firme Greenland International Consulting Ltd (Greenland) a été chargée de réaliser un examen par une tierce partie du Plan de restauration de la rivière Carp (PRRC) et des projets connexes, et de fournir des commentaires à ce sujet. Pendant le processus d’examen, on a tenu compte des commentaires du public et des différents intervenants. Un comité consultatif sur le projet a été formé et chargé de fournir des données en cours de processus, et de commenter les versions préliminaires du rapport.

Modélisation

Le modèle du sous-bassin hydrographique en amont de la rivière Carp, doté de six différents modèles informatiques, a fait l’objet d’une évaluation détaillée au cours de l’examen par une tierce partie. Les modèles, malgré leur complexité et les modifications mineures qu’on a dû leur apporter, ont été jugés suffisants pour guider les décisions en matière de planification prises dans le cadre de l’évaluation environnementale (ÉE).

Les données hydrographiques manquantes ont été prises en compte dans le modèle HEC‑RAS (hydraulique). Les paramètres d’infiltration et d’écoulement étaient dans les limites acceptables des modèles hydrologiques, sauf pour la captation des eaux en amont dans le secteur rural, pour laquelle on ne dispose pas de données permettant de confirmer les paramètres locaux exacts. Les experts de Greenland ont abordé cette incertitude en créant un scénario de pire éventualité utilisant le ruissellement maximum prévu provenant de la captation d’eau en amont en milieu rural. Les débits accrus pourraient excéder de 85 600 mètres cubes la capacité d’emmagasinement de la plaine d’inondation, soit environ 12 pour cent des débits provenant de ce bassin hydrographique et se déversant dans la rivière Carp. Les experts de Greenland soulignaient que l’on pourrait tenir compte de ce volume déficitaire potentiel de différentes façons pratiques, notamment pour contrôler les sources et augmenter la capacité de stockage. Les experts de Greenland et le personnel recommandent que ce volume déficitaire soit comptabilisé par hectare dans chaque approbation de projet d’aménagement à Kanata et à Fernbank, jusqu’à ce que l’on dispose de données de surveillance pour valider le modèle.

Les experts et le personnel de Greenland recommandent qu’un intervenant (le surveillant du modèle) soit chargé de consigner les modifications apportées aux modèles et de les transmettre aux consultants affectés à divers projets, et ce dans le but de minimiser la possibilité que des erreurs de modélisation passent inaperçues. En outre, il faudrait établir des objectifs de gestion des eaux pluviales (définies comme l’écoulement maximal des eaux pluviales par hectare) pour orienter chaque demande d’aménagement, plutôt que d’appliquer le modèle à tous les cas. Même si, à long terme, cette fonction sera assumée par le personnel de la Ville, il est recommandé d’approuver un budget de 75 000 $ pour la fonction de surveillance assignée à Greenland jusqu’à la fin de l’année 2009 et de 73 000 $ pour définir des objectifs. Le personnel recommande que le coût de définition des objectifs soient recouvrés de KWOG.

Les experts de Greenland se sont penchés sur les préoccupations du vérificateur général quant à la sous-estimation des volumes d’écoulement. Un examen de la méthode de calibration a révélé un écart de calibration du fluviomètre de 0,33 mètre à la hauteur du chemin Palladium qui, conjugué au volume additionnel d’eau de ruissellement pris en compte par le modèle hydrologique rajusté, permet d’expliquer la plus grande partie du volume manquant signalé dans le rapport du vérificateur général.

Des appareils de contrôle du débit ont été installés à trois endroits : sur la route secondaire Richardson, sur le chemin Maple Grove aux passages de la rivière Carp et du ruisseau Poole. Les experts de Greenland ont confirmé que les endroits sélectionnés permettront éventuellement de recueillir les données nécessaires à la résolution du calcul du cheminement des intumescences des affluents et à la validation des modèles.

Scénario de la pire éventualité

Il n’existe aucune donnée confirmant les paramètres pertinents relatifs à l’infiltration et à l’écoulement en ce qui concerne les bassins hydrologiques ruraux d’amont (p. ex., les eaux d’amont du ruisseau Poole). Greenland a levé cette incertitude en élaborant un scénario de la « pire éventualité », établissant les paramètres à leur juste valeur maximale. La modélisation de ce scénario de la « pire éventualité » a démontré que les débits accrus pourraient excéder de 85 6000 mètres cubes la capacité de stockage. Greenland et le personnel recommandent que toute demande d’aménagement future absorbe une partie proportionnelle au hectares concernés du volume déficitaire jusqu’à ce que des données soient disponibles afin de confirmer les paramètres corrects pour les bassins hydrologiques ruraux d’amont. Le personnel recommande en outre qu’un quart du volume déficitaire soit réduit par le biais de l’élargissement permanent du couloir, ce qui donnera une souplesse permanente dans la restauration en ce qui a trait à la fois au volume déficitaire et au changement climatique.

Restauration de la rivière Carp

En vertu du plan de restauration proposé, l’examen par une tierce partie a révélé que la capacité totale de stockage de volume d’eau augmentera dans le couloir de la rivière Carp. Le concept du canal de débit minimal accroîtra la vélocité de l’eau, améliorera le transport des sédiments et réduira les risques d’embâcles. Par ailleurs, le plan proposé n’aura pas pour effet d’augmenter les niveaux d’eau à la hauteur du pont de l’autoroute 417.

Le Plan de restauration de la rivière Carp aura pour effet d’améliorer le transport et l’équilibre des sédiments de ce cours d’eau dégradé. Elle aura aussi pour effet d’améliorer la qualité de son eau et de sa fonction d’habitat grâce à la végétation le long de ses berges et l’introduction d’aires naturelles comme des étangs à poissons et des terres humides.

Les experts de Greenland recommandaient d’imposer un plafond de 65 pour cent à l’aménagement de la zone de développement de Kanata Ouest et de Fernbank avant de procéder à la restauration. De plus, pour réduire au minimum l’investissement dans des installations provisoires, le personnel recommande de lancer un appel d’offres pour les travaux de construction de la phase initiale du projet de restauration, dans les 24 mois suivant l’approbation des 22 projets d’évaluation environnementale pour Kanata Ouest.

Le personnel recommande la révision du plan de mise en œuvre pour Kanata Ouest, de façon à y intégrer les autres recommandations de l’examen par une tierce partie concernant les mesures visant à protéger la capacité de débit et la qualité de l’eau de la rivière Carp.

Une fois le Plan de restauration achevé, on disposera d’élévations d’après exécution dont on pourra se servir pour mettre à niveau le modèle HLEC-RAS et établir une nouvelle cartographie de la plaine d’inondation du couloir.

Fernbank

Selon les experts de Greenland, il n’est pas nécessaire, à ce moment-ci, d’incorporer aux modèles les terres en amont de Fernbank (une fois les travaux hydrologiques prêts). Les projets d’aménagements dans le secteur de Fernbank peuvent être approuvés sous réserve des critères d’approbation du Plan de conception communautaire. Ces critères exigeront que les débits de pointe ne dépassent pas les conditions d’aménagement existantes et que le volume d’écoulement ne soit pas au-delà des 40 000 mètres cubes indiqués pour les conditions d’aménagement existantes lors de pluies centennales.

Incidence sur les évaluations environnementales

Les résultats des modèles corrigés n’influent pas sur les recommandations formulées dans les évaluations environnementales. Plus précisément, ni les sept ÉE de portée générale ayant fait l’objet des demandes d’Arrêté de la partie II, ni les 15 ÉE de portée générale approuvées ne sont influencées par les modifications apportées aux modèles, que ce soit au niveau des décisions de planification ou des évaluations environnementales.

Changements climatiques

L’adaptation du volume dans la pire éventualité offre une certaine souplesse quant aux effets des changements climatiques. Toute mesure de contrôle à la source et toute augmentation de la largeur du couloir mises en place pour faire face à ce volume déficitaire, permettra de conserver une souplesse à long terme. L’orage de septembre 2004, utilisé pour la calibration des modèles, a déversé plus d’eau que des pluies centennales et n’a pas généré de crues d’eau excédant les limites d’inondation actuelles à la hauteur des ponts sur ce tronçon de la rivière Carp.

Approbation des demandes d’aménagement à Kanata Ouest.

En mai 2008, le Conseil municipal a adopté une motion fixant les critères d’approbation des demandes d’aménagement à l’extérieur des limites de la plaine d’inondation à Kanata Ouest. L’approbation de l’examen par une tierce partie par le Conseil serait conforme à la motion du Conseil et autoriserait le personnel à traiter les demandes d’aménagement à Kanata Ouest à l’extérieur de la plaine d’inondation s’il juge, en consultation avec le bureau local du ministère de l’Environnement de l’Ontario (MEO, que la demande n’est liée à aucun des sept projets d’ÉE de portée générale contestés.

Aucun aménagement des terres à l’intérieur de la plaine inondable ne sera approuvé avant que l’évaluation environnementale du projet de restauration de la rivière Carp n’ait été approuvée et que les autres conditions de la modification proposée au Plan officiel de restauration de la rivière Carp aient été remplies.

Exigences de l’Arrêté du ministre du 21 juillet 2008

L’Arrêté du ministre exige que la Ville et l’Association des propriétaires fonciers de Kanata-Ouest (KWOG) fassent rapport au Bureau du district d’Ottawa et à la Direction des autorisations environnementales du MEO sur un certain nombre de questions liées aux résultats de l’examen par une tierce partie. Le personnel et l’Association des propriétaires fonciers de Kanata Ouest procéderont à la révision et à la mise à jour du projet de restauration de la rivière Carp, de l’étude-cadre des besoins en matière de viabilisation et du Plan directeur des transports pour y incorporer les résultats de l’examen par une tierce partie ainsi que toute autre modification découlant des conditions formulées par le ministre et toute la correspondance provenant d’organismes et du public concernant les projets. Un avis d’achèvement sera délivré, avec tout ce que cela suppose, y compris une période de consultation publique de trente jours, et toutes les conditions relatives à la période de commentaires, y compris les conditions concernant les demandes d’Arrêté de la partie II.

Incidences financières :

Si le Conseil approuve les recommandations 7 et 9 du présent rapport, une somme supplémentaire de 148 000 $ sera requise.

Les coûts de construction d’installations optimales de gestion des eaux pluviales pour les aménagements de Kanata-Ouest et de Fernbank, évalués à 73 000 $, y compris les fonds pour éventualités, seront financés au moyen de l’ordonnance interne n^o 903940 – Restauration de la rivière Carp. Il se peut qu’environ 95 p. 100 de ces coûts soient recouvrés auprès de l’association des propriétaires fonciers de Kanata-Ouest (KWOG), conformément à la recommandation du personnel.

Les frais à engager pour retenir les services d’un « gardien modèle » ont été évalués à 75 000 $. Le budget de fonctionnement de 2009 (entre de coûts 112737) prévoit les crédits nécessaires.

Le coût de la participation de la Ville à la restauration de la rivière Carp (30 p. 100) a été révisé et s’établit à 2,6 millions de dollars. Le Conseil a approuvé dans le budget de 2007 une somme de 390 000 $ correspondant à la contribution de la Ville aux travaux de restauration et de construction de la première année, en vertu de l’ordre interne 903940 – Restauration de la rivière Carp. Le solde sera demandé dans le cadre des futurs budgets d’immobilisation. Si la recommandation 10 est adoptée, le calendrier d’exécution débutera en 2011.

Consultation publique et suggestions :

Le rapport de l’examen par une tierce partie a été affiché sur le site web de la Ville, publié dans les journaux The Citizen et Le Droit, et envoyé au vérificateur général, et un avis a été envoyé par courriel à chaque personne ayant présenté une demande d’Arrêté de la partie II ou formulé des commentaires sur le Cadre de référence.. Une séance d’information sur les directives techniques a eu lieu le 9 avril 2009.

Dix mémoires ont été reçus. Les commentaires et réponses ont été résumés dans un tableau intitulé Document 8 et joint aux présentes.

BACKGROUND

Events leading to the Third Party Review of the Carp River Restoration Plan and Related Projects date back to 2000 and involve planning for both the Carp River Subwatershed and the new Kanata West community. Council approved the general land use and development principles for Kanata West in 2003 and the Carp Watershed/ Subwatershed Study in 2005. Both plans recommended restoration of the Carp River, a heavily degraded watercourse where historical channel alterations had resulted in sediment accumulation and poor water quality and fish habitat. The mouths of two tributaries, Poole Creek and Feedmill Creek, were also impacted by the sedimentation in the Carp, while the creeks were subject to erosion and instability.

Three Class Environmental Assessments were completed in 2006 to support development of the Kanata West area. To manage all of the planning and development issues in coordinated fashion the owners of lands within the Kanata West area established the Kanata West Owners Group (KWOG). On April 12, 2006, Council adopted Official Plan Amendment 39, which authenticated the KWOG as a landowners group in accordance with the provisions of the Official Plan. The City and KWOG acted as co-proponents for the three environmental assessments (EAs): the Kanata West Master Servicing Plan for municipal water, sanitary services and stormwater; the Kanata West Transportation Master Plan; and the Carp River, Poole Creek and Feedmill Creek Restoration.

The three EAs processes developed, evaluated and selected preferred alternative servicing and restoration scenarios for the Kanata West community at the planning level. For example the Master Servicing Study evaluated the number of pumping stations, and the choice between forcemains and gravity sewers along various alignments. It also considered the number and location of stormwater management ponds. The Restoration EA considered alternatives such as do nothing, hardening the river edge or natural channel design. Once natural channel design was selected, the EA process considered full restoration or local restoration of the river. Full restoration of the river was ultimately recommended within Kanata West and local restoration was chosen for Poole and Feedmill Creeks.

Altogether, the three EA documents supported 22 infrastructure projects. The Carp River restoration plan recommended full restoration of the Carp River to reintroduce bends and increase river stability, improve sediment transport, and enhance biodiversity, among other improvements. The restoration plan also proposed filling 28 ha of land within the flood plain above the level that would be reached by floodwaters. These lands would accommodate three stormwater management facilities and urban development.

Several organizations and individuals expressed concern about the proposed flood plain encroachment. Following Council approval of the recommended projects and the filing of the notices of completion for the environmental assessments in June 2006, several parties filed Part II Order requests with the Ministry of Environment. These requests asked the Minister of the Environment to consider “bumping up” the Carp River Restoration project and six other projects to a status that would require individual assessments. In the months that followed, the City met with Part II Order requesters in an attempt to address their concerns.

In 2007 the Auditor General at the City initiated an audit of the Carp River watershed study and related projects. Acting on a call to the City’s Fraud and Waste Hotline, the Auditor General examined whether the Carp River watershed study was consistent with all applicable policies and legislation, especially with regard to flood plain policies and the environmental assessment process. The audit also considered whether the City and consultants working on Kanata West projects faced potential conflicts of interest. This last matter was resolved through separate staff reports with recommendations that addressed these concerns to CSEDC and Council.

While the audit was in process, City staff identified missing water flows in the model that was used in the environmental assessments. The principal consultant of record confirmed that water flows were missing. Since the Minister was still considering the Part II order requests, the Ministry of Environment was contacted immediately once the errors were confirmed. The consultants of record proceeded to correct the model errors and revise the restoration plan to account for the missing water volumes.

The Auditor General’s report was released to Council on April 23, 2008 and considered by Council on May 14, 2008. As a result of both the Auditor General’s recommendations and the model errors discovered by staff, the Management Response to the audit recommended that a Third Party Review be conducted of the modelling used as the basis for the Carp Restoration Plan and the impact of any errors on the three environmental assessments. At its meeting of June 25, 2008, Council approved the Terms of Reference for the review, subject to further amendments as may be requested by the Auditor General. Staff met with the Auditor General’s office and incorporated their comments into the final Terms of Reference.

The Minister of Environment issued an order on 21 July 2008 under the Environmental Assessment Act to the City and the Kanata West Owners Group. The order indicated that the documentation of the three environmental assessments must be revised to include the results of the Third Party Review and to address other issues raised by the Ministry. Once the documents have been revised, notices of completion must be re-issued with an opportunity for a 30-day public comment period and provisions for Part II Order requests. The letter from the Minister is attached as Document 4.

The purpose of this staff report is to:

§ Present the results of the Third Party Review;

§ Propose actions to implement key findings and recommendations;

§ Respond to matters arising from the Minister’s Order, Council motions and other matters not addressed in the Third Party Review.

DISCUSSION

The Third Party Review

The Third Party Review was tasked with providing an objective third party opinion on the work that has been completed to date. More specifically it was to address Council’s Terms of Reference, which included a number of requirements including:

§ Review of hydrologic and hydraulic models

§ Determine whether the modeling adjustments impact the 22 Class EA projects

§ Review the conditions and thresholds for interim development

§ Review the application of Provincial policies and guidelines to the project

§ Comment on the timing for geotechnical investigations

§ Assess the geomorphology

§ Address other issues raised by the provincial ministries, the Auditor General, the public, and other interested parties.

The Terms of Reference for the Third Party Review are found on the City’s website at http://www.ottawa.ca/residents/public_consult/carp_river/tor_en.html.

Selection of Third Party Consultant

Greenland International Consulting Ltd. was contracted to complete the review after a multi-stage selection process that included several screenings to eliminate any firms with a conflict of interest. All firms submitting proposals had to provide a signed Conflict of Interest Declaration

Form. Signing the form confirmed that the firm had:

a) had no affiliation in any way with the Kanata West Lands Project;

b) not worked for the City of Ottawa in the past five (5) years;

c) not worked for any Kanata West Owners Group developer in the past two (2) years; or

d) not worked with any consultants related to this project in the past two (2) years.

Stakeholder Involvement and the Project Advisory Committee

The review process included input from various stakeholders. Greenland met individually with the Auditor General and the four Part II Order requesters to hear their concerns first-hand. As co-proponents of the environmental assessments, the Kanata West Owners Group was briefed as the review progressed. Also, a Project Advisory Committee was struck to advise Greenland and review and comment on drafts of the reports. The committee consisted of staff from the Mississippi Valley Conservation Authority, the Ministry of the Environment, the Ministry of Transportation and the City; staff from R.V.Anderson, acting as an engineering consultant to the City; and Dr. Barry Adams from the University of Toronto Department of Engineering who has a strong background in water resources and modelling. The committee met six times and was consulted at each stage of the process. One Part II Order requester chose to present to the Project Advisory Committee, including Greenland, rather than meet individually with Greenland.

The Third Party Review report is attached as Document 1 to this report. The main tasks set for the review and the findings for each task are summarized in Document 5. This report focuses on key findings that affect implementation of the recommendations of the Third Party Review and development within the Carp subwatershed.

Modelling

Highlights of Greenland findings and recommendations

Council’s Terms of Reference required a number of key matters related to modeling be reviewed by the third party review. The following describes Greenland’s conclusions with respect to these matters.

Hydrology models represent the flow of water over the surface of the earth, taking into account rainfall, overland flow, stream flow, infiltration and groundwater movement. Hydraulic models represent the movement of water in a defined channel or water body such as a lake or a river channel, including water velocity and depth of flow.

The Third Party Review has concluded that the models, although complex and recently requiring adjustments, are sufficient to guide planning decisions made in the Class EAs.

The June 2008 revised HEC-RAS (hydraulic) model has all of the hydrologic inputs introduced at the appropriate locations. The previously missing hydrographs, identified by staff, have been accounted for in the updated model.

As well, the final versions of the hydrologic model were updated to reflect the drainage area changes identified by the Auditor General for Poole Creek. The reduction in drainage area results in less runoff volume into the tributary and subsequently the Carp River.

Hydrologic model adjustments were recommended by Greenland and completed by CH2MHill. This reintroduced some unaccounted for overland flow comprising five per cent of the total overall volume during a 100-year storm event.

Greenland investigated the Auditor General’s concern about underestimated runoff volumes. A review of the calibration methodology determined that there was a 0.33-metre datum shift that should have been applied at the Palladium Drive gauge that would have accounted for a significant portion of the volume reported missing by the City’s Auditor General. The datum shift relates to water that was pooling against the measurement gauge and was not accounted for in the model calibration or Auditor General’s analysis. The gauge would register 0.33 metres with zero flow. Also when commencing the comparison, the water level in the model and level registered by the gauge should be the same at the outset of the event being evaluated. Coupled with the additional overland flow volume being re-accounted for in the newly adjusted hydrologic model, most of the missing flood volume in the Auditor General’s report can now be explained.

Greenland tested other standard storm distributions and concluded that the SCS 12-hour storm duration is the appropriate controlling event for this work. (SCS is a reference to an assumed design storm pattern developed by the U.S. Soil Conservation Service and often used in models to estimate flood flows.)

To date, the model of the Carp River Subwatershed used as a decision making tool, is made up of six different software inputs. Each time there is a change in one of the models, there is the potential for re-running several software packages to confirm the subsequent impacts. Potential problems that may occur include:

§ A particular modeler lacking proficiency across several software models

§ Keeping track of changes

§ Ownership of particular changes made to the models

To address this matter, Greenland is recommending that one party (the model overseer) become responsible for documenting any changes to the models and circulating them to the consultants working on the various projects that impact the watershed. Further, the City should consider setting targets (expressed as maximum stormwater runoff per hectare) for stormwater management to guide individual development applications, rather than re-running the model in all cases.

Staff recommendation

Staff supports Greenland’s recommendation for a model overseer role. This function should reside in the Infrastructure Services and Community Sustainability department once staff has developed the knowledge and capabilities necessary to use the full range of models that have been deployed for this project. In the interim, it is recommended that Greenland be retained as the interim model overseer.

Staff believes that the use of maximum runoff targets rather than model runs would simplify the approvals process particularly for smaller developers with limited resources. It would also reduce the opportunity for introduction of errors into the model when it is used by various consultants. Given their in-depth knowledge of the model, it is also staff’s recommendation that Greenland be tasked to develop a set of targets and review development applications. Development of the targets is estimated to require four months and a budget of $73,000, including contingency. Staff recommends that the cost of target development be recovered from KWOG. Greenland would be contracted and supervised by City staff. Payment for Greenland services would be the responsibility of the City to avoid perceived conflicts of interest and ensure objectivity.

In addition to these measures, staff recommends that the choice of hydrologic models be limited to the four software packages that have already been employed (Qualhymo, XPSWMM, DDSWMM, and SWMHymo). This will help to minimize the introduction of further complexity into the model.

Recommendation 7 authorizes a budget for the development of maximum runoff targets to be used instead of model runs. The City would pay for the preparation of these targets and recover the cost from KWOG. Recommendation 9 authorizes a budget for retention of Greenland as “model overseer” in the short term.

Worst Case Scenario

Greenland findings and recommendations

Given the lack of sufficient storm events to confirm the model for the Carp River, Greenland established a worst-case scenario. Infiltration and runoff parameters were within acceptable ranges for the hydrologic models, except in the upper rural catchments (e.g. headwaters of Poole Creek) where data does not exist to confirm the appropriate parameters. Conditions in these catchments create difficulties in assessing runoff during the 100-year storm event. Bedrock is close to the surface and the volume of water and the rate that it will reach the Carp River cannot be verified without monitoring data from additional storm events.

The Third Party Review dealt with this uncertainty by setting the runoff parameters from the upper rural catchments at the maximum values that could logically be expected to be used for these areas in order to create a worst-case scenario. Modeling of this “worst case” scenario found that the increased flows could exceed storage by 85,600 cubic metres. This volume is the result of a potential 12 per cent increase in flow volumes to the Carp River from the upper Poole Creek catchments. Greenland has suggested that the deficit volume could be accounted for in a variety of ways, through measures such as increased on-site storage within subdivisions, increases in downstream flow efficiency, creation of additional interim storage capacity, and corridor width adjustments. The Third Party Review recommends that all future development applications should account for a per hectare share of this deficit volume. This worst-case scenario can be adjusted once data are available to confirm the correct parameters for the upper rural catchments.

With regard to the level of additional information required to calibrate all models and validate the water level and flow modeling results, Greenland has identified two issues: the parameters for the upper rural catchments and the routing of flows through the tributary corridors. Storm events of 25 mm volume or greater may be suitable to validate the routing of flows through the tributary corridors depending on storm duration. This volume is typically found in at least four events a year. The volume should be distributed over a two to six hour duration to allow for meaningful measurements to be taken. The minimum requirement to confirm the model would be one additional monitored flood event supported by several small events of the type just described that could be used to gauge the upper catchment response

Flow monitors have been installed in three locations: in the Carp River at Richardson Side Road and at Maple Grove Road and in Poole Creek at the Maple Grove Road crossing. Greenland has confirmed that the selected locations for present monitoring efforts will eventually provide data to resolve the tributary concerns and give sufficient events to complete the validation of the models.

Staff recommendation

Staff from the City and the MVC support the requirement that all future development applications in Kanata West and Fernbank account for their per hectare share of the deficit volume based on the worst-case scenario until monitoring data is available to confirm the models. This proposed requirement is contained in Recommendation 4 and will be added to the Implementation Plan for Kanata West and the Community Design Plan for Fernbank and to all development applications. City staff will not accept measures to account for deficit volume that rely on the ongoing cooperation of private homeowners, such as rain barrels, as this may be problematic from an enforcement perspective. Staff recommends that a quarter of the deficit volume be provided through a permanent widening of the corridor. This will provide ongoing flexibility in the restoration for both the deficit volume and for climate change. The locations for widening will be determined in the final design of the restoration plan.

Carp River Restoration

Greenland findings and recommendations

The overall flood storage capacity will increase in the Carp River corridor with the proposed restoration plan.

The proposed Carp River Restoration Plan incorporates a low flow channel design that will increase velocity, improve sediment transport and reduce the potential for ice jamming. Greenland is recommending that no additional geotechnical investigations are needed for the Class EA documentation.

Another important concern that was to be addressed through the review included the anticipated flood levels at the 417 bridges. Greenland’s analysis concluded that there would be no increase in flood levels at the Highway 417 bridges. The September 2004 storm was greater than a 100‑year rainfall event and it did not create flood levels that exceeded the present flood lines at any of the bridges in this part of the Carp River, including the 417 bridges.

Once the Restoration Plan has been completed, there will be as-constructed elevations that can be used to update the HEC-RAS model in order to establish new flood plain mapping for the corridor.

The Third Party Review considered whether there is a threshold to development that can proceed without the completion of the Carp River restoration and the increase in flood storage capacity it brings. With provision of additional storage for the deficit volume as described above, the Third Party Review recommended that the cap should be set at a maximum of 65 per cent of the development area of Kanata West and Fernbank. The area closest to the Carp River can only be serviced once the Carp River restoration has been constructed, including the proposed stormwater management facilities.

Development can proceed to full build-out once the restoration plan is complete and either 1) monitoring data are available to confirm the model or 2) the deficit volume of 85,600 cubic metres is accounted for by other measures.

Staff recommendation

The draft Implementation Plan for the Kanata West Development Area prepared by Delcan in December 2007 states that development and/or fill placement within the flood fringe would require the commencement of the Carp River Restoration project. Construction is to occur in three phases, starting at the north end and take three to six years to complete. Once started, the restoration work will continue in a consecutive manner until completion.

The restoration of the Carp River has been central to the Kanata West concept from the beginning and only a limited amount of development should be allowed to proceed before triggering implementation of the restoration. Moreover, three of the stormwater management facilities are located in the flood fringe and will only be available once the restoration plan is built. The restoration needs to be constructed on a timely basis so that these facilities can be built rather than investing in a number of costly interim facilities.

Staff recommends that the trigger for construction of the Carp River Restoration project be linked to approval of the Class EAs rather than a percentage of development area. Once the EAs have been approved, a number of additional permits must be obtained prior to construction. These include authorization from the Department of Fisheries and Oceans under the Fisheries Act, approval under the Canadian Environmental Assessment Act, approval from the Ministry of Natural Resources under the Public Lands Act as there is Crown land in the corridor, and approval from Transport Canada under the Navigable Waters Protection Act and permits from MVCA under Section 28 of the Conservation Authorities Act. Allowing time to obtain these additional approvals, staff recommends that Council require that the contract for the first phase should be tendered within twenty-four months of approval of the three EA documents for Kanata West. This is likely to fall sometime in 2011. This approach to triggering implementation of the Restoration Plan has the added advantage of providing a clearer indication to the City and KWOG of when funds will be required to implement the restoration. This also provides a clearer timeframe to the “interim” development scenario.

Fernbank Development

Greenland findings and recommendations

The Third Party consultant has concluded that the Fernbank lands in the developed condition do not need to be incorporated in the models at this time. Development in the Fernbank area can be approved subject to conditions that require that peak flows not exceed existing conditions and that increases in run-off volume do not exceed an additional 40,000m³ above existing conditions for the 100-year event.

Staff recommendation

Staff has reviewed this position regarding peak flows and increases in runoff volume not exceeding 40,000 cubic metres and are recommending that this restriction be applied to the Fernbank lands tributary to the Carp River when the Community Design Plan is brought to Council for approval.

Impact on Class EA Projects

Greenland findings and recommendations

Greenland concludes that the outcome from the corrected models does not affect the recommendations of the environmental assessments. Specifically, neither the seven class EA projects subject to the Part II order requests nor the other 15 Class EA projects are impacted by the model changes at the planning decision/EA level. While the model changes do increase water levels and flows in Poole Creek, this will only have an impact on the subsequent detailed design of the creek crossings and any interim stormwater management facilities discharging to Poole Creek, but not on the EA recommendations.

Increases in Water Levels

Greenland findings and recommendations

The Terms of Reference required that the Third Party Review comment on the criteria for allowable increases in flood levels. Greenland advised that a 10 cm range of flow level change should be acceptable for comparison purposes. This is valid only if there is no existing flood risk previously identified at the particular location. Water level changes greater than 10 cm could be supported with field data to indicate that there is no flood risk. (This entails examining each site affected by higher water levels to ascertain that no buildings are flooded; access to buildings is not impeded; and infrastructure continues to function as designed.

The hydrologic model adjustments to reintroduce some unaccounted for overland flow increased water levels under existing conditions as shown in Table 3-2. (The unaccounted for flows were from existing development in the Stittsville area.) The cumulative impact of this change and future development including the restoration on water levels is shown in Table 3-6.

Staff recommendation

With respect to flood risks, the MVCA has consistently required through the analysis of the Carp River restoration plan a site-specific review of all potential increases in flood risk. This would apply to increases in 1:100 flood level of five cm or greater, as compared to the existing conditions. This requirement will continue to apply to this project.

Throughout the development of the Carp River restoration plan, MVCA has consistently required a site specific review of potential increase in flood risk, if the predicted flood level increases for the 100-year rainfall event are five cm or more higher than the existing conditions. This requirement will continue to apply to this project.

Some of the increases in Table 3-6 are greater than 10 cm, particularly between Hazeldean Road and Palladium Drive. These increases have been checked against field data to ensure that there is no flood risk.

In particular the impact of the higher water levels on the Sensplex and Smart Technologies sites has been examined. Even with the increased 1:100 year Carp River water levels, flooding from the river will not spill onto either site. The floor of the Sensplex building is more than 0.5 metres and the floor of the Smart Technologies building is 0.8 metres above the increased flood levels. The buildings will not be flooded and access to both buildings is not impeded.

Flood water will backwater through the storm sewer system and pond around the catchbasins in the parking lot on the Sensplex site. The stormwater management design for the Sensplex property already incorporates and uses ponding around the catch basins in the parking lot (maximum 0.3 metres during the 1:100 year storm or maximum elevation 94.7 metres). This is a standard design provision for stormwater management control. Therefore, during a 1:100 year storm, runoff from the site will be detained in the SWM pond and in the parking lot as designed. The peak 1:100 year water level in the Carp River (94.66 metres) will backwater through the storm sewer and occupy the same ponding areas and depth around the catchbasins in the parking lot as designed for the site stormwater management system. The storm sewer for the Smart Technologies site outlets to the storm sewer along Palladium Drive. Therefore, flood risk and/or potential flood damage is not increased for these properties.

Although there is no increase in flood risk, staff recommends that the restoration plan be revised to decrease the water levels such that there is no back up of floodwater on to the parking lot. This may include widening the corridor between Maple Grove Road and Palladium.

Issues beyond Terms of Reference

Greenland examined several issues that were not included in the Terms of Reference (after their meeting with the Auditor General and the Part II Order requesters). One issue was the proposed emergency overflow from a pumping station to a SWM pond in the event of a catastrophic failure. (See Section 8.2.3) Greenland concluded that this approach is reasonable, and advised that the ultimate design flow of 400 l per second would require eight plus hours to fill the SWM facility. As an extra measure of protection Greenland recommended that the emergency response protocols for this facility have an additional maintenance response that would require a shut off of the SWM facility outlet if this scenario occurs. A backup maintenance pumping solution should be feasible well within this eight-hour plus timeframe. In Section 7.2, Greenland, after considering concerns raised regarding water quality from a Part II Order requester, recommends that the Implementation Plan specify oil grit separators, bioretention filters or other technologies for addressing specific types of contaminants in runoff for land uses where these contaminants likely originate.

Staff recommendation

Staff supports these recommendations. They are included in the changes that are proposed to the Implementation Plan.

Costs of Carp River Restoration

Retention of Greenland International to be “model keeper” and reviewer of model runs or model changes associated with development applications on an interim basis until City staff assumes the role in January 2010 has been estimated at $75,000. The actual cost will depend on the number of applications requiring model runs and the availability of monitoring data from storm events. The $300,000 budget approved for the Carp Third Party Review has been spent on Phases 1 and 2.

The cost estimate for the Carp River restoration has increased due to two factors-inflationary price increases since the estimates were prepared in early 2007 and design changes to account for the water volume from the missing hydrographs. The design changes include three additional fish habitat ponds, expansions of habitat ponds already in the restoration plan and refinements to floodplain grading. The cost of the Carp River restoration is estimated to have increased from $6M to $8.5M.

As approved at the 03 May 2006 Planning and Environment Committee the Carp River restoration project benefits Ottawa residents at large as well as Kanata West and adjacent developments. In recognition of this public benefit of a healthy river and public open space that includes trails along the River, 30 per cent of the costs are to be attributed to the City and the landowners would pay the other 70 per cent of the restoration costs. The City, as a landowner in Kanata West, will contribute approximately five per cent of the 70 per cent.

Based on the contribution rate of 33.5 per cent, and a revised total estimated cost of the Carp River restoration of $8.5M, the City’s share will be approximately $2.85M. Council approved $390,000 in the 2007 budget for the City’s contribution to the first year of restoration construction. The balance is to be completed in three phases. It is estimated that funding for the first phase will be requested in the 2011 Capital Budget.

To potentially avoid some of this cost increase, staff wishes to investigate whether corridor width increases would be a less expensive way to accommodate the increased water volumes than additional fish habitat ponds. Staff will bring a more detailed report to Council on the cost implications of the restoration plan for the City when the design has been finalized and costs have been estimated with more precision.

Minister’s Order of July 21, 2008

The Minister’s Order was issued after Council approved the Terms of Reference for the Third Party Review. Some of the issues raised in the Order have now been investigated by staff.

Inconsistencies in application of one and two-zone floodplain policies

The Minister’s Order required that the City and KWOG report back on the “impacts, if any, of the inconsistencies in the application of one and two-zone floodplain policies.” Following receipt of the Minister’s letter, the Mississippi Valley Conservation Authority (MVCA) contacted and met with the district office of MOE to clarify the reference to “inconsistencies.” It has been determined that the inconsistencies relate specifically to the Sensplex and Smart Technologies properties on the east side of the Carp River. As detailed in the meeting notes to which both parties have agreed (Document 6) the Ministry had several concerns:

There was fill placed without an equalized cut(s) to maintain flood plain storage along the Carp River. According to MOE , this may result in property owners, who were not informed of this occurring, having to replace flood plain storage which could potentially impact the development potential of their lands.

The existing two-zone areas and the proposed flood fringe area of the Carp River, within the Kanata West area, will not be recognized appropriately in the City of Ottawa planning documents, and;

The maintenance of flood plain storage will not be adequately addressed before the start of filling of the flood fringe areas.

On the first point above, both the Sensplex and Smart Technology sites have part of their parking lots and the site specific stormwater management facilities located within the Regulatory (1:100 year) flood plain of the Carp River. This has reduced flood storage volume by 650 m³ on each site. However, the overall flood storage volume in the Carp River corridor will increase with the proposed restoration plan by 36,000 m³ to a total of 935,000 m³ of storage after the restoration plan. Therefore the “lost” storage of 1300m³ has more than been accounted for in the restoration plan and one of the property owners has contributed to funding the restoration plan. There will be no impact on the development potential of other lands.

The second point is addressed by the proposed official plan amendment for the Carp River Restoration.

The City Official Plan update contains a revised two-zone floodplain policy that has been reviewed by the Third Party consultant and found to be consistent with Ministry of Natural Resources (MNR) policy. The revised policy identified four specific areas of existing development where a two-zone floodplain policy may be applied. The draft policy does not permit lot creation in these four areas. Originally it was staff’s intent to include in the same amendment a specific floodplain policy for the Carp River restoration. However with the decision to conduct a Third Party Review, it was staff’s opinion that the site-specific amendment should come forward only when the results of the Third Party Review were available.

The key elements of a proposed Official Plan Amendment for the Carp River Restoration are in Document 2. The Carp River restoration will redefine the floodplain in this area. The proposed amendment applies an overlay, called the Carp River Restoration Policy Area, to the lands that will no longer be in the floodplain. The Official Plan amendment removes this area from the floodplain but does not permit development in the area until certain conditions are met. These conditions include an approved EA for the Carp River restoration plan; that the physical construction of Phase 1 of the proposed restoration works has commenced; that MVCA has issued a permit under Section 28 of the Conservation Authorities Act to remove the lands from the Regulatory (1:100 year) Flood Plain of the Carp River; that the filling of the property and an as-built survey will have been completed to demonstrate that the area is entirely removed from the floodplain; and that the flood storage capacity of the corridor will be maintained at or above existing conditions at all times. Once all conditions have been satisfied, a property in the Carp River Restoration Policy Area may be rezoned on the basis of the underlying urban designation without an amendment to the Official Plan. All sites along the Carp River where development has been permitted under the two-zone concept will be part of the Carp River Restoration Policy Area.

When the Carp River Restoration is completed, there will be as-constructed elevations that can be used to update the HEC-RAS model in order to establish new flood plain mapping for the corridor. At that time MVCA will amend their floodplain mapping and the City will amend its Official Plan to reinstate the one zone concept for this area.

The proposed OP amendment addresses MOE’s concern that the existing two-zone areas and the proposed flood fringe area for the reach of the Carp River within the Kanata West area will not be recognized appropriately in the City of Ottawa planning documents. It also requires the maintenance of flood plain storage.

MOE’s concern about maintenance of floodplain storage will also be addressed through changes to the Implementation Plan recommended by the Third Party Review. The Third Party Review recommended that the flood conveyance and storage capacity of the corridor was to be maintained at all times, including during construction of the restoration. The Implementation Plan for the Kanata West Development Area (which corresponds to the development phasing plan required by MOE) will be amended to implement the various Third Party Review recommendations with respect to other measures to protect flood capacity and water quality in the Carp River. These proposed revisions have been summarized in Document 3.

Approval of Recommendation 11 would require that these revisions be made to the Implementation Plan.

Response to Council motion re jurisdiction

At its meeting of 25 June 2008, Council also directed that letters be sent to the Ministry of Environment (MOE) and Ministry of Natural Resources (MNR) to address jurisdictional issues and conflicting requests with regard to the Terms of Reference for a Third Party Review for Kanata West. These letters were subsequently sent and MOE responded saying that the Ministry of Natural Resources (MNR) is the provincial lead on issues related to floodplain management. However, the Minister of Environment stated that MOE:

“has broad jurisdiction under the Environmental Assessment Act (EAA) to consider the potential environmental impacts of a proposed undertaking…Given the wide scope of the EAA and the fact that EAA compliance precedes other approvals, the Minister has the obligation to consider issues that under other circumstances would fall within the jurisdiction of other agencies.”

The complete MOE response is attached as Document 7.

Climate Change

In addition to the Minister's Order, the letter from the MOE Minister dated 21 July 2008 also contained the following request:

"I would also like the City and KWOG to consider climate change adaptation in the

Kanata West development area, particularly with respect to future flooding events."

City-wide efforts and studies

The City of Ottawa takes the matter of climate change seriously and has been developing and implementing both mitigation and adaptation strategies to address the issue. In January 2005 Council approved the City's Air Quality and Climate Change Management Plan. In 2007 the Inventory of Air Contaminant and Greenhouse Gas Emissions prepared for the City by Senes Consultants Inc. revealed that the City had exceeded its corporate GHG emissions reduction target of a 20 per cent reduction from 1990 levels by 2007. In fact the City reached a 24 per cent reduction in 2004. Community GHG were five per cent above 1990 levels in 2004.

The City is developing a climate change adaptation strategy (at the corporate level). An initial workshop that involved City staff across a number of Branches was held in January 2009. The presentations from this workshop are on the OCCIAR web site at: http://www.climateontario.ca/workshops.html

The workshop was presented by the Ontario Centre for Climate Impacts and Adaptation Resources (OCCIAR) and demonstrated a risk-based approach to climate change adaptation. This is the methodology that the City has chosen to develop its adaptation strategy.

One of the presenters, Ms. Heather Auld of Environment Canada, stressed that the science of predicting local impacts of climate change is constantly improving and that it is important to always consider a number of scenarios or models since the assumptions on GHG emissions and hence the impacts vary. There is consensus among modelers that in Ottawa the number of heat waves and the number of days of heavy rainfall events will increase and frequent wetter periods are more likely. However, local models do not yet predict the anticipated increases in rainfall for a 100-year design storm. It is likely that much of the rainfall increase will fall in intense rainfall events and that conditions will be drier between events.

The City (and the predecessor Region of Ottawa-Carleton) has participated in studies of the local impacts of climate change. This includes a study done in 2001 for Natural Resources Canada under the Climate Change Action Fund entitled Impacts and Adaptation of Drainage Systems, Design Methods & Policies[1]. The Mississippi Valley Conservation Authority also participated in this study, which concluded that the federal and provincial governments need to play a stronger role in water management to ensure a consistent, comprehensive and integrated approach to water management, including the impacts of climate change on aquatic systems and drainage issues. The report also recommended that drainage design criteria be reviewed and revised based on a detailed cost-benefit approach analysis and risk assessment considering the threat of climate change. Lastly it recommended changes in analysis and design methods, including moving away from simplistic methods such as the "Rational Method" which is heavily reliant on historical data.

A study by Watt, Climate Change and Urban Stormwater Infrastructure in Canada[2], also considered a local example. The urban catchments of the Central Park subdivision in Ottawa, were examined under a scenario of rainfall change to determine possible impacts that global climatic change may have on the stormwater infrastructure of Ontario. In this area:

· Surface storage on streets and parking lots is used in the stormwater management system during storms less frequent than the five-year storm

· ponds for water quality control only

· utilizes some of the most modern stormwater quantity control mechanisms including, orifices in the catchbasins, local infiltration, and by directing roof runoff to the lawns

Since effort has been taken to reduce the flows entering the sewer system there are few options to retrofit the existing sewer system to cope with climatic change. The study considered how the minor system might be redesigned if the design storm were to increase by 15 per cent. Existing sewer pipes would surcharge under this scenario of increased rainfall. Therefore, to convey the increased peak flows, the diameter of these pipes would need to be increased. The incremental cost of installing larger diameter pipe was estimated at about two percent of the total system cost. The additional cost of larger sewers to accommodate the increased flows expected under climate change is not large in relative terms.

Similar studies concur with this approach (Infrastructure Canada December 2006)[3]. "A study in North Vancouver found that drainage infrastructure could be "adapted to more intense rainfall events by gradually upgrading key sections of pipe during routine, scheduled infrastructure maintenance. When changes to infrastructure such as pipe size are necessary, it is predicted to be less costly than the possible losses due to failed infrastructure"

Changes in the Upper Carp Subwatershed

This is a large subwatershed, approximately 5000 hectares. Of this, 3000 hectares is approved for urban development in the City 's Official Plan, in Stittsville and Kanata, including Kanata West.

The Kanata West Development Area is planned to be implemented over a 20 +/- year period allowing any new policies and information to be incorporated as development proceeds. As part of the Carp River Restoration Project, one of the few permanent water flow monitoring systems in Ottawa has been put in place for Kanata West. The results from this monitoring will be beneficial in determining the effects of climate change over time and the adaptive management measures that can be put in place to accommodate increased flows and assist in developing municipal policies.

Continuous monitoring of water level and/or streamflow (year round) will occur at three locations in the upper Carp River watershed: Carp River at Richardson Side Road, Carp River at Maple Grove Road, and Poole Creek at Maple Grove Road. All of these streamflow monitoring stations will be permanent gauges as part of the ongoing MVC long term monitoring program. Data from the Kinburn gauge may also be useful in assessing long terms trends.

While the imperviousness of Kanata West development is expected to be typical or slightly higher than historic urban development (due to intensification requirements in the Provincial Policy Statement), both the Carp River Subwatershed Study and the Master Servicing Study require that infiltration rates be maintained. This requirement is being implemented with each development application and also moderates the increase in runoff resulting from urbanization.

Potential Adaptation Strategies

The worst case scenario created by the Third Party Review consultant requires that an additional 85,600m³of water volume be accounted for by all development applications on a per hectare basis until such time as data is available to confirm the model of record. Many climate change references suggest a 15 per cent increase in rainfall as the upper end of the range of climate change impacts. The study by Watt, Climate Change and Urban Stormwater Infrastructure in Canada, is an example. Assuming a 15 per cent increase in rainfall, the CH2MHill model of record would receive 110.4 mm of rainfall instead of the present 96 mm. Since their model produces a 44.1 per cent conversion to runoff, a climate change adjusted model would result in the 110 mm of rainfall converting to 48.7 mm of runoff.

The adjusted model that Greenland has suggested to be used in the interim as a worst-case scenario presently converts to 48.1 mm of runoff. This is almost equivalent to what is being suggested in the references as a climate change impact.

The accommodation of this worst-case volume provides a cushion of flexibility with regards to the impacts of climate change over the short term. Any at-source control measures put in place to accommodate this deficit volume will continue to provide flexibility over the long term.

Staff are recommending that at a least a quarter of the deficit volume be accounted for by a permanent widening of the corridor. This will provide additional resiliency over the long term for climate change.

When data is available to confirm the model of record, before the deficit volume required for the worst case scenario is modified or abandoned, a review of both provincial and City policy should be conducted to determine whether some or all of this flexibility needs to be maintained as a climate change adaptation measure. This would also include reviewing the monitoring data to determine if any trends can be established. Should the monitoring data be available before the province's expert panel has provided its recommendations on stormwater management and climate change has reported, a decision on the deficit volume should be deferred until the panel has reported.

Although it is anticipated that current applications will be approved based on the City guidelines and standards in effect now, the long implementation period for the development provides the opportunity for future approvals to be based on revised standards as City-wide or provincial guidelines are put in place.

Another option to maintain flexibility is to reserve sufficient land adjacent to the proposed SWM facilities to accommodate increased water quality storage volumes resulting from increases in rainfall intensity.

In terms of flooding, another adaptive management response would be to further improve the volume of water conveyed safely by continuing the restoration of the Carp River through the rural reaches to the village of Carp. Areas closest to the river can only be developed after the restoration is constructed providing additional flexibility.

It should also be noted that Kanata West has already experienced a greater than 100-year rainfall event. The September 2004 storm resulted in more than 118 mm of rain in 12 hours. This is 22 per cent more rainfall than in a 100-year statistical event. The September 2004 event did not create flood levels that exceeded the present flood lines at any of the bridges in the reach.

The recently updated City of Ottawa Infrastructure Master Plan outlines several Steps Toward a New Approach to Stormwater Management. This includes requiring an adaptive management approach to allow on-going reassessment of stormwater management activities and, if necessary, redirection of programs. In this new model, there is a shift away from a focus on the technical issues of infrastructure systems towards the broader planning and management issues important to long term sustainability and common to all infrastructure. Critical to an adaptive management approach is the development of monitoring programs that can evaluate the success or failure of stormwater management efforts from the perspective of stream health rather than strict effluent criteria.

City staff advises that the impact of climate change on drainage and flooding is an issue that requires a consistent approach, preferably based on federal and provincial guidance, but if not, at least on a citywide basis. Should City or provincial guidelines be established to deal with the flooding impacts of climate change, they will be applied to land draining to the Carp River as they are applied elsewhere in the City or province.

Going Forward

Development Approvals in Kanata West

In May 2008 Council adopted the following motion with respect to applications for further development in Kanata West:

That any application for approval for development for lands within the floodplain not be brought forward to Committee and Council for approval, or not be approved pursuant to delegated authority, until such time as the Carp Restoration Environmental Assessment has been approved by the Minster of the Environment.

That in addition to other requirements of the Planning Act, any application for development approval within Kanata West, for lands outside the floodplain only be brought forward to Committee and Council for approval, or approved under delegated authority if:

1) The Carp Restoration Environmental Assessment has been approved by the Minister of the Environment; or

2) The Council Directed Review of the Carp Audit has been completed and reviewed by Council with Council being satisfied that development can proceed; or

3) The applicant, either alone or in concert with other developers, has provided a comprehensive analysis for all development in Kanata West, satisfactory to City of Ottawa, that addresses the question of stormwater, whether or not the Carp Restoration Environmental Assessment is approved.

Council approval of Recommendation 13 in this report would indicate that condition no. 2 above has been met for lands outside the floodplain in Kanata West.

With respect to the processing of development applications, it is the Department's opinion that all applications outside of both Kanata West and the Fernbank lands which drain to the Carp watershed can be processed at this time without awaiting the final approval of the seven EA projects against which the Part II Order requests were originally filed. Within Kanata West and the Fernbank lands, development applications will need to be reviewed on a case-by-case basis to determine if the works contained therein are reliant on resolution of the EAs, which are not yet approved, or whether those applications may proceed prior to the resolution of the contested EA projects. Consultation with the local Office of the Ministry of the Environment will be required until the outstanding EA issues are resolved. For those applications that are not dependant on the approval of the seven EA projects, it will be a requirement to clearly demonstrate how the additional storage volume required in the worst-case scenario can be accommodated as part of the development.

Requirements of the Minister’s Order of 21 July 2008

the impact of modelling errors on the 22 Class EA projects
the impacts, if any, of the inconsistencies in the application of one and two-zone floodplain policies
the level of additional information required to calibrate all models and validate the water level and flow modeling results,
the details of a water level and flow rate monitoring plan for the Carp River, Feedmill Creek and Poole Creek
a detailed development phasing plan for development occurring within the Kanata West development area.

For all matters, the City and KWOG are to consider whether the changes warrant revisions to the Carp River Restoration Project, Master Servicing Study and Transportation Master Plan.

The Order also directs that the City and KWOG shall revise and update the Carp River Restoration Project, Master Servicing Study, and Transportation Master Plan to include the results of the third-party review as well as the development phasing plan, any other changes resulting from the Minister’s conditions and all agency and public correspondence related to the Projects. The City and KWOG are to reissue a Notice of Completion, complete with a 30-day public comment period, and all the provisions of the comment period, including provisions for Part 11 Order requests.

Recommendation 2 requests that Council authorize staff to fulfill these requirements, based on the results of the Third Party Review and the other information contained in this report.

City staff will meet with MOE Directors in Toronto after Council deliberates on this report, to inform them of the Third Party Review and how it dealt with the stakeholder and Part II Order requesters’ concerns, and discuss next steps in the process.

Lessons Learned

This experience has demonstrated how important it is to have a clear assignment of responsibility for being the "model keeper," especially when a model is complex and is being used by several consultants. Staff supports several measures to reduce the possibility for model errors. These are:

Clear assignment of the role of “master” model overseer to ensure that changes to the model are properly documented and circulated to all consultants working on various projects that could be impacted by these changes;
Development and use of maximum stormwater runoff targets for use in the development approvals process for Kanata West and Fernbank to minimize the requirement for model runs;
Restricting the choice of hydrologic model software packages; and
Requiring that documentation for all model runs include a concise hydrologic summary report that relies upon simple catchment maps, plotted hydrographs of key points and tributaries, plotted water surface profiles showing watercourse features, bridges and crossings, and summaries of flows and volumes and all parameters in tabular format.

Another general lesson was that with long and complex projects, the fresh perspective provided by a peer review can be very valuable. This is similar to having a bridge design stamped by two engineers. Staff intends to deliberately bring new staff into the project from time to time to provide this fresh perspective.

PUBLIC CONSULTATION/INPUT

The report of the Third Party Review was placed on the City’s web site on 9 April 2009 for public review and comment. Advance notice of the posting of the report was provided by individual e-mails to everyone who made a Part II Order request or who provided comment on the Terms of Reference. Ads were also placed in The Citizen and Le Droit newspapers on April 10, 2009. A technical briefing was conducted on 9 April 2009. A copy of the Third Party Review report was provided to the Auditor General in advance of the technical briefing.

Ten submissions were received. The comments and responses have been summarized in a table attached as Document 8. In some cases the comments have resulted in clarifications to the Third Party Review report, but there have been no major changes in the findings or recommendations.

Several submissions questioned the objectivity of the Third Party Review. Staff believes that the level of analysis and the recommendations in the consultant’s report demonstrate that the review was done thoroughly and without bias. The worst-case scenario has placed additional requirements upon development in Kanata West and Fernbank and provided a way for the project to move forward while dealing with the uncertainties in the model calibration and protecting public safety.

The time provided for public review was criticized. Staff acknowledges that the time was not generous, but the detail in submissions received indicate that it was adequate.

FINANCIAL IMPLICATIONS:

If Council approves this report’s Recommendations 7 and 9, an additional $148,00 will be required.

The retention of a “model keeper” has been estimated at $75,000 and funds are available in the 2009 Operating Budget in Cost Centre 112737.

LEGAL/RISK MANAGEMENT IMPLICATIONS

There will be the opportunity for individuals to request an individual environmental assessment (a bump-up request) should Council direct the issuance of Notices of Completion for the seven environmental assessments not yet approved.

Should such a request be received, staff will seek to advise the Ministry of the Environment as to how the bump-up requests have been addressed by the third party review.

SUPPORTING DOCUMENTATION

Document 1 - Greenland Consulting Intl Ltd. Third Party Review – Carp River Restoration Plan

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

Document 2 - Carp River Restoration Official Plan Amendment

Document 3 - Proposed Revisions to Implementation Plan for Kanata West

Document 4 - Minister's Order of 21 July 2008

Document 5 - Task Tables of Third Party Review

Document 6 - Notes of MVCA/MOE meeting on “inconsistencies”

Document 7 - MOE response to jurisdiction issue

Document 8 - Table of Responses and Comments

DISPOSITION

Staff of Planning and Growth Management in association with KWOG will proceed to fulfill the requirements of the Minister of the Environment’s Order under the Environmental Assessment Act including:

a. Provide a summary of the Third Party Review results;

b. Explain how the 22 Class EA projects are not impacted;

c. Report on the implementation of the floodplain policies;

d. Report on required Water Level and Flow Modeling Data;

e. Report on required Water Level and Flow Monitoring Plan;

f. Incorporate the results of the Third Party Review into the Monitoring and Development Phasing Plan;

g. Provide all agency and public correspondence; and

h. Update Class EA project documentation and issue new Notices of Completion including a 30-day public review for the seven projects previously subject to Part II Order requests.

Staff of Planning and Growth Management in association with KWOG will also report back on climate change adaptation as outlined in this report and requested by the Minister of the Environment.

CARP RIVER RESTORATION PLAN

OFFICIAL PLAN AMENDMENT DOCUMENT 2

1. Amend Schedule K, Environmental Constraints, to delete some areas from the flood plain as shown in Figure 4. (Figure 4 would be a large scale map showing the fill areas that would be deleted from the flood plain)

2. Amend Schedule B, Urban Policy Plan, to add “Carp River Restoration Policy Area” as shown in Figure 5. (Figure 5 would be the same areas as shown in Figure 4, but they would now be on Schedule B)

3. Amend Section 3 of the City of Ottawa Official Plan by adding a new Section 3.11 “Carp River Restoration Policy Area” as follows:

3.11 - Carp River Restoration Policy Area

Policies

1. Lands in the vicinity of the Carp River between Hazeldean Road and a point north of Campeau Drive, are designated ‘Carp River Restoration Policy Area ’ on Schedule B of this Plan. The Restoration Policy Area is an overlay over urban land-use designations. The purpose of the Restoration Policy Area designation is to recognize that proposed channel modifications and restoration works will allow for development of this area. However, a number of conditions must be met before development is allowed to proceed:

a. The Minister of the Environment will have approved the Carp River, Poole Creek and Feedmill Creek Restoration Class Environmental Assessment;

b. The Kanata West Landowners Group, or the City, will have commenced the physical construction of Phase I of the Carp River restoration works between Richardson Side Road and Highway 417;

c. Mississippi Valley Conservation Authority will have issued a permit under Section 28 of the Conservation Authorities Act to remove the lands from the Regulatory (1:100 year) Flood Plain of the Carp River for the property to be re-zoned; and

d. Filling of the property and an as-built survey will have been completed to demonstrate that the area is entirely removed from the floodplain.

e. At all times, the flood storage capacity of the corridor will be maintained at or above existing conditions.

2. Once all five conditions have been met, the zoning by-law may be amended on the basis of the underlying designation on these lands. An Official Plan Amendment will not be required to revert to the underlying designation provided the conditions listed in Policy 1 have been met.

RECOMMENDED CHANGES TO IMPLEMENTATION PLAN DOCUMENT 3

Requirements for interim facilities

Key erosion and sediment control facilities for any interim development phases should be located outside of the flood plain and not be incorporated as part of the facilities that will be constructed adjacent to the Carp River flood corridor.

Interim SWM facilities are to be designed for post to pre conditions up to and including the 100 year storm event.

Any interim SWM facilities proposed to outlet to Poole Creek will require the active storage for peak control to be above the 100-year flood level in Poole Creek. This flood level has been increased with the revision of the XPSWMM models for the Carp River restoration.

The suggested change in peak flow on Feedmill Creek for existing conditions from the worst case scenario hydrologic model for upper catchments should be used for the plans for this corridor until such time as monitored data collected can substantiate the CH2MHill model results.

Interim SWM facilities north of Highway 417 will require an outlet that can be set at an elevation that ensures a positive grade to the existing creek invert. Typically these interim facilities will have difficulty being positioned closer than 200 to 400 m from the creek depending on the area.

Phasing of Carp River Restoration

The fringe areas proposed for filling in the vicinity of Pond 1 should not be filled until such time as the Restoration Plan has advanced to provide sufficient overall flood storage volume in the study corridor.

It will be necessary to describe the construction phasing to maintain an active flow channel that will ensure safe conveyance of flows at all times. This information should accompany permit applications to the MVC.

The phasing plan should also focus on maintaining a full flood control volume at all times through the process. There are locations downstream of Richardson Side Road as well as most road crossings that indicate silted channels that cause localized backwater conditions. By starting from the downstream end of Richardson Side Road with the phasing, there are increased efficiencies that would be realized for low flows as the project proceeds upstream.

The restoration construction is proposed to be phased over a six-year period. It will be difficult to install the SWM facilities for Pond 4 and 5 until that particular phase of the corridor construction is underway. The construction plan will require additional documentation during detailed design to outline the slope construction measures to be implemented in the field.

Measures to Protect Water Quality

The Implementation Plan is the appropriate document to assign specific values or targets for enhanced infiltration and other low impact development measures as a means of source control that will assist in meeting objectives. Oil grit separators, bioretention filters or other technologies for addressing specific types of contaminants in runoff should be specified for land uses where these contaminants likely originate.

Sediment load during the interim phasing will have the potential to increase due to disturbances in the channel and within the floodplain, thereby requiring specific attention that would be built into the plan review and permit process. The plans being put forth during detailed design to show the phases of construction would show measures for normal silt control to minimize any sediment loading. These plans should also demonstrate how siltation control would be augmented during conditions where the entire corridor would be inundated with a more severe event. Silt curtains have been suggested in the restoration plan. Additional detail should be provided by the contractor during the permit application process.

MINISTER’S ORDER OF JULY 21, 2008 DOCUMENT 4

TASK TABLES OF THIRD PARTY REVIEW DOCUMENT 5

These tables provide a summary of the conclusions for each task in the Terms of Reference.

Phase I Tasks – Third Party Review – Carp River Restoration Plan

Phase 1 – T of R Task Description	How Task was Addressed by Third Party Consultant
1. To understand the history and scope of the project, the 3^rdparty will be required to meet at minimum with the Auditor General and the Part II Order Requesters.	Early in the review process the Third Party Review Team met with the Auditor General and his consultant and had separate meetings with three Part II Order requesters. A detailed presentation was also received by the PAC from one of the Part II Order Requesters. Notes of these meetings will form part of the documentation for new Notices of Completion.
2.Confirmation of the accuracy of the basic data and information used in the models.	The original models were run to determine whether the same results were achievable. The focus then shifted to the final corrected models. - Existing XPSWMM Model - There was a conduit overflow feature that had to be repaired to account for 7.5% of the total volume generated in the 100 year storm. A sensitivity analysis was completed on the parameters used for the upper rural catchments. - Existing HEC-RAS model – The revised hydrographs from the hydrologic model were imported into the HEC-RAS models including adjusting the tributary model flows - Future HEC-RAS model – There were some minor structure coding issues to be addressed at the proposed bridge structures. The consultant of record has made these changes. The revised hydrographs from the hydrologic model were also imported.
3.The models used in the Auditor General’s report and the results obtained.	Sec 3.4 of the Third Party report describes the limitations of Auditor General review by not running the XPSWMM models.
4.Assess the appropriateness of models used and the application of the design storms used to establish the flows and water levels along the Carp River.	Although cumbersome to use and requiring some recent adjustments, these models give more than just a planning level representation of conditions in the watershed. This is discussed in Section 2.3 and in the Phase 1 conclusions in Section 8. Based on the nature of the Carp River and the complexity of development being proposed, the models provide the flexibility of use to be an appropriate tool for the planning level and as a platform for investigations during detailed design. Several previous studies have identified the 12 hour storm duration as the controlling event. A review of local rainfall information shows that a 2 hour volume also can create conveyance impacts in the local reaches of the river. A review of other standard storm distributions were tested and summarized in Section 6.6. and concluded that the 12 hour duration is appropriate for this work.
5. The corrected hydrologic and hydraulic models representing the original restoration plan and the corrected models representing the modified Restoration Plan, including all return periods (i.e. 2 year to 100 year flows).	The corrected HEC-RAS model has included the features as indicated on the revised restoration plans. The input hydrographs are all included. The SWM facilities have the volume accounted for correctly. Other area site plans have been coded in the future conditions model. See Section 2.2.2.3,Section3.1,Section 3.3,Section 3.4
6. The impact of reported drainage area errors (recognizing Fernbank lands included in its under-developed state).	Section 6.1- The reduction in drainage area results in less runoff volume into the tributary and subsequently the Carp River. This volume would be as much as 186,380 to 211,700 m³during the 100-year event.
7.The criteria used in the Hydraulic Design Brief for the allowable increases in upstream and downstream flood levels, flows and velocities.	With the recently revised HEC-RAS model prepared in Jan 2009, some of the criteria used in the Hydraulic Design Brief have now been replaced. The key change recommended was to not artificially increase the Manning’s parameter at particular structures to balance water levels. The result is slightly elevated water levels in the vicinity of Richardson Side Road. The water level change of 10 cm is considered within an acceptable range. MVCA requests field confirmation that there is no flood risk for changes 5 cm or greater and does not support any increase in water levels in areas where there is a known flood risk. See Section 6.9
8.The infiltration and runoff parameters used in the model to estimate surface runoff volumes and how these were accounted for, in the model calibration including the volume of the 2004 calibration event.	Discussed in detail in Sec 2.2.2.1 and Sec 5. Infiltration and runoff parameters were within acceptable ranges, except for the upper catchments where data does not exist to confirm appropriate parameter values. The upper rural catchments will have the largest impact on the runoff volume over the duration of a 100 year event. Parameters were skewed to establish a worst case scenario for runoff volume. The impact is on the recession limb in Poole Creek and the Carp River but increases the peak flow from Feedmill Creek for existing conditions. A volumetric exercise was completed to account for volumes being received in the Carp River corridor regardless of timing of flows. This confirms the worst condition to be anticipated. A review of the calibration procedure identified the source of the volumes that were supposedly missing. The overland flow issue accounts for 150,000 m³ of this missing volume. Adjusting upper catchment parameters can account for additional potential volume. Table 3-2 shows changes and identifies the new existing conditions model. Greenland identified a datum issue in the calibration procedure (Section 4) that also reduced the missing volume identified by the AG significantly. Coupled with model changes and accounting for backwater influence on the gauge, the volume issue can be resolved.
9.The hydrologic and hydraulic model calibration procedures used, including the sensitivity analyses carried out and utilization of current stream flow records on the Carp River, Manning’s “n” factors, etc.	Many stormwater management projects proceed with limited field data to calibrate. The MNR guidelines suggest other procedures to augment limited data. Data transfer for urban catchments and a sensitivity analysis for the upper rural catchments framed the potential variability of results. The previous sensitivity analysis focused on the impacts on water levels in the Carp River. The use of one event to calibrate both the hydrologic and hydraulic model at the same time is difficult to defend. The monitored data is also only depth data without a rating curve assigned. Other ways to utilize this data were considered in Section 4 The Third Party Review focused on volumetric issues to respond to Part II Order Requester concerns. A worst case set of conditions were established that could be used to set interim development targets until such time as additional monitored data confirm upper catchment hydrologic responses. The Manning’s n parameter value at Palladium Drive in the existing conditions model is at the high end of the normal range. With the datum shift, it is possible that this value may be reduced. Typically, adjusting Manning’s n by less than 50% results in very little change to flow conditions.
10.The selection and orientation of cross sections used to model the existing and proposed floodplain conditions.	The HEC-RAS models have a considerable number of cross sections spaced predominantly 5 metres apart. This gives the flexibility to adjust to the design changes that have taken place and represent cut fill adjustments. The positioning of facilities has been done to ensure SWM facility volumes are not double-counted. (Sections 3.3.4 and 3.3.5)
11.The hydraulic routing procedures used to combine the hydrologic inputs and produce the water level estimates, including the steady flow and unsteady flow computations.	Section 6.2 identifies how the routing information from the XPSWMM model can be compared with the HEC-RAS model in the Carp River so that the starting boundary conditions in the steady state HEC-RAS models for Poole Creek and Feedmill Creek can be and have been substantiated.
12. The appropriateness of the hydraulic model parameters used to establish water flow, volumes and water levels, such as cross-sections, slope, crossing details, existing and proposed fill in the floodplain, and floodplain storage.	The overall flood storage volume in the corridor will increase with the proposed restoration plan. The hydraulic model has been set with a levee station to show where the fill locations are to be considered. The model set up is flexible should these fill areas have to be shifted as more information becomes available through the monitoring process. In Sec 6.9 the hydraulic design brief model parameters strategy was reviewed and recommendations made to readjust parameters at structures to normal values. The more important place to focus was on the hydrologic model to get appropriate flows to introduce into the hydraulic model.
13.The method of demonstrating the maintenance of floodplain storage in the restoration reach for interim and future development conditions, including balancing cut and fill on a range of return period basis for the entire reach (i.e. 2 year to 100 year flows), versus balancing on a 0.30-metre incremental elevation basis for individual applications.	Demonstrating floodplain storage cut fill balance by the 0.30 m incremental elevation basis is usually done for individual applications where a watershed corridor solution has not been determined. The technique can be awkward to apply over a long reach and usually is confirmed with hydraulic modelling. The Third Party Review Team established rating curves from the HEC-RAS models for both existing and future conditions upstream of Richardson Side Road to determine the flood storage available for equivalent flow rates and determined there is an additional 36,000 m³ of available flood plain storage with the future corridor arrangement. This volume is introduced in the lower flow regimes (less than 10 cms) thereby introducing additional protection during the low flow events. It was determined that this is a valid means to establish the flood corridor volume. See Section 6.5
14.The impact of existing and proposed culverts and bridges on flows and water levels within the restoration reach and downstream and the potential impact of ice and ice jams on water levels through the restoration reach and downstream.	The impacts of existing and proposed culverts and bridges have been summarized in Section 6.7. There are no flood level impacts with the structure arrangement proposed. The potential impact from ice jams was discussed in Section 6.3. The manner in which the future corridor is to be constructed would keep the main ice formation in the redefined low flow channel. Therefore with the future corridor/channel there will be a lower potential for any ice jamming. (p. 61)
15.Assess the requirements for flow and water level monitoring for the Carp River to calibrate the models and implement the restoration plan.	Ongoing monitoring will provide data to confirm flow responses for a variety of scenarios. See Section 7.1 The selected locations for present monitoring efforts will eventually provide data to resolve the tributary concerns and complete the validation of the model. (p. 76)
16.The adaptive management measures established in the draft Implementation Plan for updating the models as development progresses and monitoring data becomes available to assess flows and water levels, and minimize flood risk.	Additional recommendations have been made to the adaptive management measures to account for the worst case scenario until such time as data collected substantiate the adjusted XPSWMM and HEC-RAS models. Sec 7.2 describes limits on phasing of development until these models have been substantiated with additional validation events. This information is also expanded in Section 4.2 of the Phase 2 section of this document.
17.The analysis of storm water management facilities, habitat restoration pools and floodway width and their impact on flows and water levels.	These features were reviewed in Section 3.3.2 and determined to be adequately described in the models.
18.Review the stormwater management criteria and whether additional storm water quantity controls are required to mitigate development impacts.	Kanata West, once developed, will generate 145,000 m³ additional runoff volume. The proposed facilities have an active volume of 100,500 m³ for extended detention volumes. They are adequately designed since they will address the frequent events and provide additional protection during more common storm events. Due to the nature of the corridor (ie slow moving) there is less evidence of additional improvements with an increase in post to pre controls to the 100 year event. See Section 6.8. The proposed SWM facilities are adequate for quantity control should the volumetric issues resulting from the worse case scenario be addressed through other means as suggested. (p. 72) Future interim facilities have been recommended to have full 100 year post to pre controls. (Section 4.1 Phase 2)
19.Validate and re-run the models and produce final flows and water levels for the restoration reach and the downstream Carp River. Consider the MNR Technical Guide “River and Stream Systems: Flood Hazard Limits” with regards to how the Restoration Project is designed.	Additional changes were requested and made to the corrected hydrologic and hydraulic models. The revised XPSWMM models with conduit adjustments provided new input hydrographs to the existing and future HEC-RAS models. The impacts for existing and future conditions are summarized in Table 3-2 and 3-6. These models were subsequently run to provide information to help frame the worst case scenario to establish targets to be applied until there is monitored data to validate the models.
20.Comment on the acceptability of any increases in existing flood levels and/or velocities for the 2 to 100 year return period events for the restoration reach and existing upstream and downstream developments.	There is an increase in water levels in Poole Creek due to the latest correction in the hydrologic model. The existing conditions dynamic HEC-RAS model for the Carp River also has starting water levels that are up to 10 cm higher. The water level change is reduced further downstream in the model. Future design considerations should not impact flood levels in the Carp River corridor or the two main tributaries in this study area. A 5 to 10 cm change in water level is indiscernible in field measurements due to undulations in the stream surface flow conditions. Sec 3-4 Table 3-6 provides the comparison of flood levels with the revised HEC-RAS model. It is important to note that there will be no impact to existing flood levels at the Hwy 417 structures.
21.Prepare a Phase 1 report outlining the findings of the model review/validation/re-run in terms of flows and water levels and implications for the Restoration Plan and the other 22 Class EA projects in the Kanata West area including structuring and phasing related to the issues raised in Phase 1.	The model reviews and changes have implications to water levels predominantly in Poole Creek. A review of the Class EA projects that has been completed would suggest an update to the Restoration Plan EA to reflect the modified flood levels in Poole Creek. The Schedule C transportation projects with structures crossing Poole Creek will require amendment to the functional design features included in the documentation. There are no impacts to the planning level decisions that were made for these Schedule C projects. There are no changes to the Carp River corridor that warrant any changes to the other EA projects. Any Poole Creek water level modifications should be taken into account with detailed design applications for interim phases of development being considered as part of the adaptive management measures outlined in the Dec 2007 Implementation Plan.
22.Briefing and presentation of Phase 1 results.	Phase 1 results were presented to the Project Advisory Committee.

Phase 2 Tasks – Carp River Restoration Plan - Third Party Review

ToR Task Description	Response in Report
1. Address the appropriate timing within the process for geotechnical investigations and examination of geotechnical hazards within the floodplain, including slope stability issues and impact of fill on clay/peat soils.	The issue was discussed in the context of pertinent MNR documentation (Section 2). Additional geotechnical documentation will be required to support drawings for permit applications. There will also be a need for geotechnical field support during certain construction projects with slope contouring, etc. These geotechnical measures do not need any further investigations to be included in the Class EA documentation that has been tabled. (p. 85)
2. Examine the Flow Characterisation and Flood Level Analysis, Carp River, Feedmill Creek, and Poole Creek report and advise on the timing of updated flood plain mapping to the MNR Technical Guide Standards.	A recommendation has been made to rerun the hydraulic models with as-constructed measurements to become the basis for creating new flood plain mapping once the Restoration Plan is completed. See Section 3.1.
3. Examine the measures established by the City for development in Kanata West to proceed in those areas outside the flood plain where there are approved EA’s, using interim servicing facilities and any recommended conditions on such approvals, such as additional SWM criteria, protecting opportunities for the mitigation of runoff	Interim servicing scenarios were investigated and temporary sizing criteria and positioning of outlet structures for interim facilities with outlets to Poole Creek were suggested. Also, the report recommended that no temporary sediment control facilities be installed in future SWM facilities adjacent to the Carp River. Storm trunk sewer phasing with Pond 5 construction needs to be clarified. Interim facilities are not discussed in the EA documents. See Section 4.1. See also Task 6.
4. Identify the need and timing of incorporating other tributary catchments such as upstream Fernbank lands (developed conditions into the hydrologic models.	Two scenarios were identified on how to deal with future development areas, including identifying in advance targets to be adhered to or a review of future development flow conditions if data is available. The key finding is that the Fernbank lands, in the developed condition, do not need to be incorporated in the models now because it is sufficient to require that peak flows not exceed existing conditions in the upper Carp River and that runoff volume not exceed the suggested 40,000 m³above existing conditions. (p. 102)
5. Review how the City has incorporated a policy how flood plains will be preserved as a flood damage reduction measure and ensuring the application of the Two Zone concept is applied to only existing development areas	Proposed policy 4.8.1 in the revised City Official Plan was reviewed and documented in the report. It was confirmed that it adhered to Provincial statutes and did not promote new development in flood plains. Two zone policies were only to be introduced if needed for existing development areas. See Section 3.2
6. Identify the threshold at which the impacts of runoff from interim development (ie prior to the Restoration Plan being fully implemented) needs to be further mitigated or development staging/phasing needs to be reconsidered	The main location for fill placement in the floodplain is proposed in the first phase of the corridor to be restored (Richardson to 417). This area should not be filled until such time as the restoration plan has advanced to provide sufficient overall volume in the corridor. The Implementation Plan indicated that this area will not be filled until the corridor restoration is virtually complete. (p. 98) If the worst case scenario for corridor volume is accounted for, a cap of 65% of total development area is suggested until the corridor work is completed. See Section 4.2.
7. Assess the geomorphology and whether a sediment balance can be achieved, and the need for quantitative estimates for sediment volumes and sediment transport capacity, and the impacts of any erosion and sedimentation within the restoration reach and downstream	The geomorphology review confirms the composition of material to be transported and the critical channel slope to ensure this material can be moved. The provision of a low flow channel confines where this activity occurs. The shear stresses in the low flow design require the new channel to have a stone base with vegetated banks for protection. Sediment volumes are not provided in the analyses that have been completed. It is also suggested that the composition of material will change through the phasing of development and be ultimately confined to the SWM facilities with the exception of the normal instream processes. See Section 6.
8. Review the criteria used for storm water quality treatment following the Ministry of Environment Storm Water Management and Planning Guidelines, including suspended solids removal.	A review of inherent water quality that is provided for storm water with the application of the design guidelines for best management measures was provided. The normal level of protection was established in the CRSS with agency and public input. The limitations in treating certain types of pollutants were also qualified.
9. Prepare a summary of all the work and its impact on the Carp River Restoration Plan and the implications for all 22 Class EA projects including structuring and phasing including issues raised in Phase 1 and Phase 2	Although changes in water levels in Poole Creek will affect detailed design of future crossings of the Creek, the planning level decisions from the Class EA process do not change for the transportation projects. (p. 115) The watermain projects are not impacted by the hydrologic or hydraulic modeling analyses. (p. 116) Although several issues were identified (hydraulic grade line analysis for storm trunk sewers at SWM facilities, more rigorous monitoring and maintenance for sewer to Pond 5) that require more work at the design stage, this does not impact the Class EA planning decisions for the SWM facilities. The Restoration EA is impacted by the revised hydrologic inputs only for the tributaries. The Carp River corridor with the revised model adjustments has fluctuations in water levels within acceptable ranges and there are no changes at key bridge structures, including the Hwy 417.
10. Estimated budget to complete the revised restoration plan	This estimate is found in City staff report to Council.
11. Briefing and presentation of Phase 2 findings.	Phase 2 findings were presented to the Project Advisory Committee. A technical briefing was held on April 9, 2009 of both Phase 1 and Phase 2 results, and the draft final report was posted on the City website.

NOTES OF MVCA/MOE MEETING ON “INCONSISTENCIES” DOCUMENT 6

MOE RESPONSE TO JURISDICTION ISSUE DOCUMENT 7

TABLE OF COMMENTS AND RESPONSES DOCUMENT 8

H.W. Willemsen, Stittsville

· Two issues with July 2004 Jock River Flood Risk Mapping Hydrology Report – reference to Hobbs Drain and mapping of Flowing Creek and Monohan Drain watersheds

· The watershed from Jinkinson Side Road to the Carp River ( 50 meter drop) is strongly affected by water flow in the bedrock and the topology of the bedrock.

· The current study of the Poole Creek watershed excludes all of the bedrock water east of the Pipeline to Jinkinson from flowing into the Carp and asserted all of it flows towards the Jock.

· About 50% of this water generally flows east along the Highway 7 –Hazeldean corridor with consequent flow south to the Poole creek watershed

· Would like the plan to incorporate his more accurate view but does not believe it would affect the findings unless the current is increased downstream.

· Overall, not unhappy with the report but believes there are incorrect assumptions about the watershed and would like to see the issues dealt with by managing the flow as preferred to storage solutions.

RESPONSE:

The provided information gives further evidence that the upper catchments of Poole Creek warrant the additional scrutiny that has been recommended by the TPR. The model of record however is a surface water model with a particular emphasis on flows that would create a high water level and thereby establish a flood line for future development purposes. The boundaries of drainage areas are based on surface water flows. They do not address groundwater flows.

Wayne Bennett, Engineer Ottawa

· The report authors have struck a reasonable balance in assessing the stormwater management issues and have provided the City a practical approach to moving forward.

· Heartily endorses the Phase 1 and 2 Reports

RESPONSE: City staff agrees.

John Almstedt

· Questions the impartiality of the consultant.

· Does not support this restoration plan.

RESPONSE:

The Third Party Review consultant was selected through a multi-stage process with several screens to ensure that there was no conflict of interest.

Mikelis Svilans, Kanata

· The time allowed for comment was too short

· Does not believe that modelling error has been corrected

· Does not believe that increased storage volumes will reduce flood risks

· Pending developments are still not included in calculations

· All permits should be delayed until further monitoring events

· MVCA should be audited

· Would like to see the flood plain mapping updated for Carp River watershed

RESPONSE:

1. The obvious error (five input hydrograph address points- station numbers changed) was confirmed in the original model file and all subsequent model runs (i.e. June 2008) and updated runs (i.e. Jan 2009) were reviewed to make sure that all hydrographs were accounted for. The water level change referred to in Table 3.6 is a result of a new repair requested by the TPR and completed by the consultant who prepared the hydrology model. The new hydrographs were then introduced into the hydraulic model that also had to be rerun as a result of this repair of the hydrology model. The onus is on the consultant who is designing the corridor to demonstrate that this model and these water level changes are satisfactory.

2. The flood storage volume comparison between the existing and future conditions is based on comparing the volume present in the corridor (indicated by model calculating and accounting for cumulative volume through the study reach) at a particular flow rate at Richardson Side Road. Greenland prepared rating curves to confirm that as a safe flow passed through Richardson Side Road; all other locations were checked for flow at that moment and the volume compiled. Since it is a dynamic model we had to look at the moment when the safe flow condition was occurring and compile the information elsewhere.

The additional volume due to elevated water levels between Palladium Drive and Maple Grove Road has not been factored into the comparison of flood storage volume.

3. Development scenarios with clay type soils are very common in the Ottawa area and the typical response from these areas is well documented without having to have specific monitored data. The additional runoff anticipated from the Fernbank lands has been reviewed with the development consultants and preliminary modeling for that area was reviewed prior to making the volume change recommendation. Although Fernbank has not been incorporated directly into the model, it has been included in the analysis and in all recommendations re phasing and development limits.

4. Having completed and reviewed several hundred modeling assignments, Greenland, in most cases have noted that there has been limited if any monitored data to use to calibrate models. In the majority of assignments, the consultant has transferred data from a known watershed, drainage catchment with similar attributes where there is data available. This particular watershed has excellent data used to model the entire watershed down to the Kinburn gauge. The area proposed for development has similar conditions that have been modelled elsewhere in the Ottawa area with success. The area where there could be some variability of response is the upper reach comprising 30% of the study area where there is a unique geologic feature that may present a variability of response. This was investigated and it was determined that the extent of the variability is up to 12% of the model of record for the upper catchments. This deficit volume has been introduced into the criteria to be applied should applications be approved.

5. There is an opportunity to build a safe corridor with the reintroduction of some natural features. Coupled with the updated mapping and analyses that have been completed, a more accurate representation of the real flood plain can be achieved. The other development and service related issues regarding the flood plain have gone through a rigorous decision making process that not only included the MVC, but other agencies and the public.

Ted Cooper, Engineer, Eganville

Third Party Review Process

· Not enough time was allowed for comment

· The Glen Cairn issue/details should have been part of the consideration of this report

· Believes that the TPR disregarded all of his comments in his October 6 presentation as well as the results of the Glen Cairn floods

· Doubts the independence of the TPR

Technical Review

· The Design Storm should have been based on an urban watershed, not a rural watershed

· There has been no credible hydro technical analysis completed on the Carp River from which it is possible to conclude no quantity SWM controls are required for events up to the 100-year event; and

· The position taken by MVC that flood level increases of 10 cm or less are within the accuracy of the computer models and are of no concern is contrary to longstanding policies used by CAs across the Province.

· Discussion in the TPR concerning storage volumes should be completely re-written so the reader can distinguish between riparian and stormwater storage volumes.

· The data collected from the 2004 Storm event will not be the same when the area is built out.

· Design of Kanata West Pump Station needs to be accurate regarding flood elevation

· HEC RAS modeling results all presuppose sufficient outlet

· The increase in flood levels between Hazeldean Road and Palladium Drive should create numerous approval issues

Policy Review

· Believes there are some two-zone policy inconsistencies in Kanata West

· Would like further explanation of changes in flood plain policies for the area with reference to Mr. Perks’ comments in 2008.

· Currently SWM ponds are not allowed in floodplains and he will challenge the changes proposed for the OP

· TPR did not put enough emphasis on prevention as recommended in the Technical Guidelines

Legal Review

· Questions why the MVCA has allowed development in the floodplain in the past

· Questions if the MVCA has received permission from the affected landowners who may have increased flooding risks

· Believes the recommendations should be rejected and the restoration plan and SW plans rethought

RESPONSE:

1. Meeting with TPR Consultant and PAC

The comments have not been disregarded by the TPR. The parameters were determined to establish a worst-case scenario to give an appropriate starting point to implementing the series of projects and associated development. The TPR has identified a volume that needs to be accounted for in lieu of having a completely calibrated model. By framing the maximum range of variability in the model of record, an additional volume is now being considered that is greater than the entire runoff to be generated by the development of Kanata West. (170,000 m³ above and beyond the 145,500 m³ being generated by Kanata West (difference in post and pre runoff 12 hr event).

The TPR is not a provincial agency and can only render an opinion based on the models that have been reviewed. It is important that provincial agencies and the MVCA have signed off since they are the mandated decision making bodies.

Technical Review

2. Design Storm Selection

The TPR maintained the use of the SCS storm due to the size of the upstream catchment that was to remain rural. At the request of the PAC, Greenland reviewed other shorter duration storms due to the nature of the urban response from smaller catchments to ensure that nothing was missed. The models that are being used incorporate the unit hydrograph theory in order to generate flows from catchments. Specific to this theory, the time of the storm must be smaller than the time between the end of the storm and the arrival of the peak (i.e. lag time). By default, the storm duration has to be less than the time of concentration, contrary to City guidelines. Reference Bruce and Clark 1966.

The length, type and intensity of the rainfall used in a simulation is based on many considerations including type of development, size of the watershed, point of interest and purpose of analysis (e.g. infrastructure design, watercourse response). The appropriate rainfall distribution for the analysis of the Carp River corridor project has been used. To address this comment the 24-hour Chicago rainfall distribution was employed and the results were similar to the 12 hour SCS analysis. The project design is still valid.

3. Double Counting Flood Storage and Riparian Storage

All development increases runoff volume regardless of whether it is having the peak shaved by stormwater storage. This additional volume eventually gets into the river and corridor. The Carp River in this reach is very slow moving. Prudent analysis would be to ensure that all volume whether stormwater or riparian is being accounted for at the same time.

MVCA has consistently required through the analysis of the Carp River restoration plan and will continue to require a site specific review of potential increase in flood risk for increases in 1:100 flood level of 5 cm or greater, as compared to the existing conditions.

4. False Sense of Security – September 2004 event

The discussion on climate change was requested by the MOE after the TPR Terms of Reference had been released. The City will respond to this point. There is some research presently underway in the province that will eventually be able to address some trends. The typical approach at present is to bump up rainfall volumes, discount certain passive features impact, etc, but these measures are at best stopgap until some meaningful trend can be established. Although the Sept 2004 event was greater than a 100-year event (volume wise), it was not as stringent as the 100-year event for shorter more intense storms. These shorter storms will still be useful for individual urban catchment analysis, but the question is whether the Sept 2004 or equivalent storm is becoming an increasing trend?

The Kanata West development will introduce an additional 144,500 m³ of runoff during a 100 year 12 hour storm. The volume analysis suggests an additional 170,000+ m³ to be introduced above and beyond the model of record. If development proceeds with these criteria, it has accounted for a reasonable estimate of the impact of potential climate change.

5. Sanitary Servicing EA projects

All model runs and scenarios show water levels within a similar range (less than 0.3 m variance) in the vicinity of the proposed pumping station. The model review does not show anything that would change the planning level decisions being made at the EA process. The concern raised is always dealt with during detailed design. The consultant has to deal with what is an acceptable level of risk in the design of the station.

6. HEC-RAS Modelling presupposes sufficient outlet

This comment assumes that the dynamic nature of the HEC-RAS model doesn’t work. The model was extended further downstream and an energy balance between subsequent cross sections is calculated and updated for each time increment during the duration of the modeling event. Therefore if there were insufficient outlet further downstream, it would be reflected in higher water levels upstream when this phenomena occurs. The slow moving nature is also compounded by the fact that there are several locations where there is temporary ponding of shallow depths of water due to sediment in the downstream channel. This work also gives evidence of extended time of some modestly elevated water levels being recorded in the field.

The channel/floodplain work ends just downstream of Richardson Side Road but the hydraulic model extends downstream to Village of Carp. Therefore any “outlet”/conveyance issues are reflected in the model reach employed.

7. Increased Flood levels

The TPR has not been given the mandate to decide how the situation should proceed but to identify the extent of the problem with the scenario being modelled. The onus will be on TSH/Aecom to demonstrate that there is no increase to flood risk to the satisfaction of MVC and the City. Greenland has always left widening the corridor as a viable option.

8. Policy Review

i) Minister’s Order

City staff has pursued the issue of “inconsistencies” and the question of floodplain policy jurisdiction. It was not in the Third Party Review Terms of Reference.

ii.) Two Zone vs. Modified One Zone

The PPS reference of 3.1.2 goes on further to identify means in which certain forms of development can take place that is consistent with what has been applied. The two-zone concept is being applied, although the terminology may vary. iii) Locating SWM Facilities in Floodplain

Likewise this type of feature can and has elsewhere been installed adjacent and in contact with the flood plain (i.e. submerged outlet).

iii) MNR Technical Guidelines and LRIA Criteria

The TPR discussed the criteria with members of PAC and the interpretation of clauses was discussed by PAC members with other government officials.

9. Legal Review

The post-development model takes into account all future modifications of the flood plain.

See response 8.

10. Conclusions

The projects are not contrary to the PPS.

David Spence

· There was not enough time to comment on report

· Document should be analysed by City’s engineers

· Believes climate change will increase flood risks

· Concerned about the quality of water coming from the developed areas

· On behalf of the Friends of the Carp River and the Riverkeepers, condemns the process and the report

RESPONSE:

The report has been reviewed by the City’s engineers. A response has been provided on climate change in the staff report. Water quality coming from the development areas will meet provincial standards.

Darlene Conway, Engineer

· Does not understand why increases shown in Table 3.6 are not used to correct restoration plan further

Calibration Issues

· Updated calibration runs should have been included in report

· Drainage downstream of Richardson Sideroad will affect post-development models and needs to be considered

· Current restoration plan and TPR do not account for poor drainage downstream of Richardson Side road

Volumetric Issues

· Rainbarrels and ponding in parks are not acceptable methods to address the volume deficit

· Believes that widening the corridor and increasing downstream flow efficiency are the best flow control options and does not understand why they are not recommended explicitly

Method to Demonstrate Maintenance of Flood Plain Storage

· The floodplain should be maintained in accordance with the LRIA guidelines

· The post-development flood storage volumes will be lower than existing

· Increasing flood levels is not acceptable as a storage method

· No distinction between riparian storage and total storage

Design Storm Selection

· Why isn’t the urban storm distribution being used instead of rural?

· Why not run the urban distribution just to dispel doubts

Stormwater Management Facility Strategy

· Finds the SWM recommendations conflicting

· SWM facilities should not be in the floodplain

Review of Hydraulic Design Brief

· Changes in water levels indicate an impact or effect

· No increases in flood levels are allowed without permission from landowners

· Proposed flood level increases need to be addressed

City Official Plan Implications

· The proposed restoration plan is a mechanism to create developable land from floodplain in exchange for stream rehabilitation. This is not consistent with the natural hazards policies of the Provincial Policy Statement (which make no mention of “modified one-zone) and is not consistent with the draft update to floodplain policies in the City’s Official Plan. This project may be unprecedented in Ontario in terms of the wholesale creation of developable land from floodplain and sets a very bad precedent

Fernbank

· The “model of record” and restoration plan should be updated to reflect full OP build-out in Fernbank before the EAs are re-posted.

· Are the Carp Road Corridor lands accounted for as urbanized in the post-conditions model?

General Comments

· Worst case scenario does not include issues of timing or conditions such as Fernbank, downstream of Richardson Sideroad, etc.

· There are many exceptions used in the report which need to be justified before development proceeds

RESPONSE:

1. Water Level Increases

The TPR was not given the mandate to decide how the situation should proceed but to identify the extent of the problem with the scenario being modelled. The onus will be on TSH/Aecom to demonstrate that there is no increase to flood risk to the satisfaction of MVC and the City. Greenland has always left widening the corridor as a viable option.

2. Calibration Issues

The TPR reviewed calibration related issues with CH2MHill, at which time their position was that their mandate was to determine the maximum water level to be attained through the duration of the storm. They stated that they have matched measured water levels and the other issues pertaining to extended water depths during the recession limb of the storm have no bearing on establishing the flood line. The TPR requested that CH2MHill review the model with the datum findings and revisit the boundary conditions to be set at Palladium Drive. CH2MHill was reluctant to do this unless there was more data collected to be used in the calibration process.

3. Volumetric Issues

City staff will not accept measures to account for the deficit volume that rely on the ongoing cooperation of private homeowners, such as rain barrels, as this may be problematic from an enforcement perspective. The other options mentioned by Greenland will be considered. Staff is recommending that at least a quarter of the deficit volume be accounted for by a permanent corridor width adjustment.

4. Method to demonstrate maintenance of flood plain storage

It is our position that other techniques are available that replace the 0.3 m incremental technique. The TPR analysis followed something similar to point 4 in the LRIA reference provided in the correspondence. The flood storage volume comparison between the existing and future conditions is based on comparing the volume present in the corridor (indicated by model calculating and accounting for cumulative volume through the study reach) at a particular flow rate at Richardson Side Road. We prepared rating curves to confirm that as a safe flow passed through Richardson Side Road; all other locations were checked for flow at that moment and the volume compiled. Since it is a dynamic model we had to look at the moment when the safe flow condition was occurring and compile the information taking place elsewhere.

The TPR rating curve analysis was completed on an earlier version of the HEC-RAS model and does not factor in the high water marks that would have occurred between Palladium Drive and Maple Grove Road. Therefore the 45,000 m³ being suggested in the correspondence is above and beyond what was used to establish the comparison. Additional volume from the elevated water levels between Palladium Drive and Maple Grove has not been factored into the comparison. It was intended to be conservative.

5. Design Storm Selection

The TPR maintained the use of the SCS storm due to the size of the upstream catchment that was to remain rural. At the request of the PAC, Greenland reviewed other shorter duration storms due to the nature of the urban response from smaller catchments to ensure that nothing was missed. The models that are being used incorporate the unit hydrograph theory in order to generate flows from catchments. Specific to this theory the time of the storm must be smaller than the time between the end of the storm and the arrival of the peak (i.e. lag time). By default, the storm duration has to be less than the time of concentration contrary to City guidelines. Reference Bruce and Clark 1966.

6. Stormwater Management Facilities

The interim SWM facilities are to be located away from the Carp River corridor and will in all likelihood outlet into drainage paths that would have to maintain the same flow conditions entering the present river corridor. Also there are interim facilities that may outlet into other tributaries temporarily. These two features are not described in the documentation that the TPR had to review. The post to pre criteria would be applied by default if these were independent applications without a watershed study to dictate otherwise.

The ultimate SWM facilities adjacent to the Carp River corridor are sized based on findings in the modeling analysis that indicated a potential of coincident peaks for Ponds 4 and 5. The provision of water quality only was applied throughout the corridor. The TPR can endorse this solution, as with any other review body, with additional data to support the model of record (specifically for timing of flows). Without this data, the TPR will agree to the strategy with the provision of the additional volume to frame the “worst case scenario”.

7. Review of Hydraulic Design Brief

The TSH hydraulic design brief identified some other rationale for allowing higher water levels by averaging the impact throughout the whole reach. The TPR discussion centered around what constitutes an acceptable change in levels provided there is no flood risk previously identified. MVC uses 5 cm. The TPR recommendation is that it can be up to 10 cm due to the variability of vegetation seasonally and field measurements could vary due to undulations in the water surface during sampling. The discussion was directed to lands within the study corridor where the ownership of the lands is within the owners group. Again the onus will be on the consultant of record bringing forth the design to secure approvals for the plan and water levels proposed.

8. City Official Plan Implications

The TPR are aware of several applications throughout the province where development has driven the flood line policy being applied. Two recent examples (Massey Creek in GRCA presently being tendered, Cawkers Creek in KRCA). Even the TRCA Valley and Stream Corridor Plan allowed for a 50% build out of building envelopes for areas where there are existing buildings. These areas were not designated Special Policy Areas under the Provincial Policy Statement but were reviewed similar to Special Policy Areas.

The purpose of the restoration plan is not to create developable land from flood plain lands. The purpose is to restore a more natural channel/flood plain system, increase/restore fish habitat and achieve a sediment balance/transport. The mechanism to achieve the restoration project (funding and landownership) is the filling of some of the flood fringe areas.

9. Fernbank Lands

The consultant for the model of record has stated that it is a planning level model that reflects the conditions at the time the model was prepared. The additional runoff anticipated from the Fernbank lands has been reviewed with the development consultants and preliminary modeling for that area was reviewed prior to making the volume change recommendation. The development consultants for the Fernbank lands are satisfied that the criteria recommended can be met. The volumetric analysis does include an allowance for the Fernbank lands in the developed condition.

The Carp Road Corridor lands are not included in the model in the developed condition. These lands do not have piped water and sewer services and will not be developed to urban densities. Restrictions can be placed on the volume of stormwater runoff permitted, if required.

10. General Comments

The worst-case scenario does look at the worst two hours in the storm and assumes that the entire volume arrives well within the two-hour window where it can be argued it may be between four to six or eight hours (to be determined with monitoring). More water is being introduced by skewing the upper reach rural catchment parameters than is generated by the entire Kanata West development. During the two-hour window this volume changes storage capacity an 80,000+-m³ surplus to the 85,600-m³ deficit when compared to the measured response from the model of record. It does include a build out for the Fernbank lands. The accounting exercise is based on flood volume capacity set at a point in the model run when there is a safe conveyance of the flow downstream of Richardson Side Road. There are points in the storm when there is more water in the system in the model but this is not being used, thus making this a conservative assessment.

Frank Hendriksen, Engineer

· Logical and prudent recommendations that he agrees with

· The reasons for the time involved in this process should be considered

· Suggests all parties should have come together to discuss in the first place

· Some duplication of engineering work

· AG’s office was perhaps not equipped to deal with this issue

· The City did not use the media to the same effect as those in opposition

· Applauds the thoroughness of the report and the recommendations

RESPONSE:

City staff agrees with the comments on the Third Party report.

Mike Green, KWOG

· Concur with the recommendation that the models be kept with one master keeper and recommend the Conservation Authority take that responsibility

· All options should remain open and be evaluated on a case-by-case basis for each application in order to permit the most appropriate measure based on local conditions and development type. If the model validation indicates these additional storage volumes are not required or can be reduced, adjustments can easily be made as development occurs.

· Would like the report to show further clarification of development thresholds and timelines to avoid any confusion

RESPONSE:

The report identifies the following with respect to model validation:

o Storm events of 25 mm volume or greater may be suitable to validate the routing of flows through the tributary corridors depending on storm duration. This volume is typically found in at least four events a year. The volume should be distributed over a two to six hour duration to allow for meaningful measurements to be taken.

o The minimum requirement would be one additional monitored flood event supported by several small events that could be used to gauge upper catchment response as previously mentioned.

The report mentions a wider range of options to account for the worst-case volumes including increases in downstream flow efficiency or flood corridor width (p. 55) and additional volume in interim SWM facilities (p. 73) as well as on-site controls.

Specifically regarding the use of on-site controls to be implemented to account for the worst case volumes (see point 2)

1. The Threshold Summary is based strictly on a volume accounting exercise. The City or MVC may have other criteria that they would apply to arrive at the threshold percentages. Also there are practical limitations that will have to be addressed with interim servicing that may mean that these percentages are not achievable.

2. A review of the measures proposed to accommodate the additional volume is as follows:

· On street storage in sags is not an option since it has already been accounted for in the criteria used in the models of record (i.e. DDSWMM model used City criteria to set flows that can get into sewer)

· Parkland storage will have to be endorsed by the City. We understand that this is not the case presently.

· Temporary expansion of ponds could have the active storage increase used in the accounting.

· Roof top/ parking lot/underground storage can be used if not already reflected in the parameters used to set up the DDSWMM model of record.

3. Suggested clarification in report

The 100 to 120 m³/ha is a suggestion that will in all likelihood require the City to enter into the target-setting program that has been recommended. The prorated amount would have to be distributed throughout portions of the watershed. Specifically, it would make sense to consider distributing this volume through each of the catchment areas to the proposed ponds. (i.e. since Pond 5 has a significantly larger drainage area than Pond 2, its drainage area would have more volume to account for)

Erwin Dreessen

· What does the increase in water levels at Maple Grove and Palladium mean for the development there?

· The indictment of the Kanata West proponents to not have made the effort to collect the necessary data years ago stands.

· It would appear that tables 6-2 and 6-4 (pages 66-68), and much of the subsequent information, compare apples and oranges.

· Would appreciate the principles explained in lay terms

· Approves of the recommendation to keep the model with one overseer

· Has never heard reference to a “modified one zone” policy before this

· Does not believe the TPR is an independent review

· Believes the urbanization of the Fernbank lands should be added to the conditions

· How was the 34% development calculation arrived at?

RESPONSE:

1. The TPR has not been given the mandate to decide how the situation should proceed but to identify the extent of the problem with the scenario being modelled. The onus will be on TSH/Aecom to demonstrate that there is no increase to flood risk to the satisfaction of MVC and the City. Greenland has always left widening the corridor as a viable option.

2. Having completed or reviewed several hundred modeling assignments, in most cases there has been limited if any monitored data to use to calibrate the model. In the majority of assignments, the consultant has transferred data from a known watershed, drainage catchment with similar attributes where there is data available. This particular watershed has excellent data used to model the entire watershed down to the Kinburn gauge. The area proposed for development has similar conditions that have been modelled elsewhere in the Ottawa area with success. The area where there could be some variability of response is the upper reach comprising 30% of the study area where there is a unique geologic feature that may present a variability of response. This was investigated and it was determined that the extent of the variability is up to 12% of the model of record. This was taken into account should the development community wish to proceed without the data that would substantiate the model. This 12% volume has been introduced into the criteria to be applied should applications be approved.

3. The TPR maintained the use of the SCS storm due to the size of the upstream catchment that was to remain rural. At the request of the PAC, Greenland reviewed other shorter duration storms due to the nature of the urban response from smaller catchments to ensure that nothing was missed. The models that are being used incorporate the unit hydrograph theory in order to generate flows from catchments. Specific to this theory the time of the storm must be smaller than the time between the end of the storm and the arrival of the peak (i.e. lag time). By default, the storm duration has to be less than the time of concentration contrary to City guidelines. Reference Bruce and Clark 1966.

4. The flood storage volume comparison between the existing and future conditions is based on comparing the volume present in the corridor (indicated by model calculating and accounting for cumulative volume through the study reach) at a particular flow rate at Richardson Side Road. We prepared rating curves to confirm that as a safe flow passed through Richardson Side Road; all other locations were checked for flow at that moment and the volume compiled. Since it is a dynamic model we had to look at the moment when the safe flow condition was occurring and compile the information taking place elsewhere.

5. There are clauses in the provincial documents that support the decisions that have been made by several agencies with the mandate to introduce the channel restoration measures and revisit flood mapping with improved data and models.

6. The TPR is recommending that an additional 170,000 m³ of runoff (going from an 87,000 m³ surplus with existing model to 85,600 m³ to be added) be accounted for until additional data is collected. There have also been additional changes to models of record.

7. The consultant for the model of record has stated that it is a planning level model that reflects the conditions at the time the model was prepared. The additional runoff anticipated from the Fernbank lands has been reviewed with the development consultants and preliminary modeling for that area was reviewed prior to making the volume change recommendation. The development consultants for the Fernbank lands are satisfied that the criteria recommended can be met.

8. There is a certain area that can be developed that will generate additional runoff volume. The development (Fernbank and Kanata West) will generate 184,500 m³ of new runoff volume with full build out. The 34% constitutes 62,900 m³ of runoff volume approx. If there is an 85,600-m³ shortfall, then development is reduced from 184,500 m³ to 98,900 m³. If the restoration plan has not been built, there is 36,000 m³ of new volume that has not been introduced therefore reducing 98,900 m³ to 62,900 m³. However, the City staff is recommending that each development application be required to include a prorated portion of this volume. Also, the restoration plan would have to commence before this build out % is achieved.

The proposed recommendations would require that all development application approvals in Kanata West and the portion of Fernbank draining to the Carp River accommodate a per hectare share of the 85.600 cubic metre deficit volume until data is available to confirm the model.

[1] Jobin, Daniel, 2001. Impacts and Adaptation of Drainage Systems, Design Methods & Policies. Presented to Natural Resources Canada ATURAL RESOURCES CANADA Climate Change Action Fund: Impacts & Adaptation Contribution Agreement A330.

[2] Watt, W. Edgar, Waters, D., McLean, R., 2003. Climate Change and Urban Stormwater Infrastructure in Canada: Context and Case Studies, Report 2003-1, Toronto-Niagara Region Study on Atmospheric Change, Report and Working Papers Series.

[3] Adapting Infrastructure To Climate Change In Canada's Cities And Communities, A Literature Review, Research & Analysis Division, Infrastructure Canada

December 2006

Report to/Rapport au :

SUBJECT:

OBJET :

EXECUTIVE SUMMARY

Requirements of the Minister’s Order of 21 July 2008

RÉSUMÉ

Exigences de l’Arrêté du ministre du 21 juillet 2008

Modelling

Highlights of Greenland findings and recommendations

Staff recommendation

Impact on Class EA Projects

Greenland findings and recommendations

Minister’s Order of July 21, 2008

Response to Council motion re jurisdiction

Climate Change

Going Forward

Development Approvals in Kanata West

Requirements of the Minister’s Order of 21 July 2008

LEGAL/RISK MANAGEMENT IMPLICATIONS

DISPOSITION

Policies

Third Party Review Process

Technical Review

Policy Review

Legal Review

Calibration Issues

Volumetric Issues

Method to Demonstrate Maintenance of Flood Plain Storage

Design Storm Selection

Review of Hydraulic Design Brief

Fernbank

General Comments