8.             PINECREST CREEK NATURAL CHANNEL RESTORATION PROJECT

 
PROJET DE RÉHABILITATION DU CHENAL NATUREL DU RUISSEAU PINECREST

 

 

 

Committee recommendation

 

That Council approve $160,000 in partnership funding for the restoration of Pinecrest Creek under the City's Stream Restoration Program

 

 

Recommandation du Comité

 

Que le Conseil approuve le financement en partenariat d’un montant de 160 000 $ pour la réhabilitation du ruisseau Pinecrest en vertu du Programme de restauration des cours d’eau de la Ville.

 

 

Documentation

 

1.      Deputy City Manager's report Planning, Transit and the Environment dated
7 May 2007 (ACS2007-PTE-POL-0031).

 

Report to/Rapport au :

 

Planning and Environment Committee

Comité de l'urbanisme et de l'environnement

 

and Council / et au Conseil

 

07 May 2007 / le 07 mai 2007

 

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

Directrice municipale adjointe,

Planning, Transit and the Environment /Urbanisme, Transport en commun

et Environnement  

 

Contact Person/Personne ressource : Carol Christensen, Manager/Gestionnaire, Environmental Sustainability/Durabilité de l’environnement, Planning, Environment and Infrastructure Policy/Politiques d’urbanisme, d’environnement et d’infrastructure

(613) 580-2424 x21610, carol.christensen@ottawa.ca

 

Bay (7), College (8)

Ref N°: ACS2007-PTE-POL-0031

 

 

SUBJECT:

PINECREST CREEK NATURAL CHANNEL RESTORATION PROJECT

 

 

OBJET :

PROJET DE RÉHABILITATION DU CHENAL NATUREL DU RUISSEAU PINECREST

 

 

REPORT RECOMMENDATION

 

That Planning and Environment Committee recommend that Council approve $160,000 in partnership funding for the restoration of Pinecrest Creek under the City's Stream Restoration Program

 

RECOMMANDATION DU RAPPORT

 

Que le Comité de l'urbanisme et de l'environnement recommande au Conseil d'approuver le financement en partenariat d’un montant de 160 000 $ pour la réhabilitation du ruisseau Pinecrest en vertu du Programme de restauration des cours d’eau de la Ville.

 

 

BACKGROUND

 

Council has established a capital budget for the restoration of streams recognizing that, as for all City assets, there is a need to maintain streams in a manner that minimizes costs and protects public health, property, infrastructure, and the environment. 


Identification of required restoration projects to date has been based on recommendations arising out of City lead subwatershed studies.  The subwatershed approach is required to ensure the recommended restoration projects are in context with the overall function of the subwatershed. 

This report recommends City funding for works that are identified through an NCC project rather than a City project.  This recommendation incorporates directions identified in the Lower Rideau Watershed Study, as endorsed by Council, to review and update priorities and management actions in partnership with other agencies to maximize benefits and minimize costs by coordinating efforts and developing common standard practices.

 

The NCC has completed a study of the erosion problems along the 2.5 km length of Pinecrest Creek that remains open above ground (The upstream and downstream portions are buried in sewers).  The project has identified contributing factors to the erosion problems and recommends long terms solutions to address extensive and on-going erosion in Pinecrest Creek that:

-     causes loss of property alongside the Transitway (Figure 1)

-     threatens the integrity of infrastructure including culverts, roadways, and pathways (Figure 2)

-     contributes to reduced capacity in culverts and structures under City and NCC roadways and pathways (Figure 3)

-     significantly degrades fish habitat due to excessive erosion

 

Urban stormwater runoff is a primary factor contributing to the erosion problems.  It dramatically increases the forces causing erosion. Pinecrest Creek has the most urbanized watershed in the City of Ottawa.  Most of the development within this watershed took place at a time prior to modern stormwater management practices.

 

The approach followed by the NCC has addressed the hydrology and erosion processes at the subwatershed level for Pinecrest Creek.  The proposed solutions follow natural channel principles that enhance fish habitat while mitigating the increased erosion forces resulting from urban stormwater runoff through a number of measures including:

-     adjusting the channel alignment to be consistent with the flow patterns, thereby minimizing problem areas that cause excessive erosion mad velocities under high flow conditions; and

-     re-establishing the connection of the channel to floodplains where the over-bank areas support the natural dissipation of energy through the distribution of high flows across larger areas instead of funnelling the flows and associated high energy through the channel.

 

The project's benefits include restoration and protection of property along the Transitway and protection of infrastructure. The approach is also being documented as a case study to provide a reference to other practitioners and agency reviewers for future similar studies and works, thereby maximizing the value of knowledge gained through the project.  On-going monitoring of the creek will provide additional information consistent with the adaptive management principles of improving our knowledge and practices in protecting and restoring streams  and aquatic habitat.

 

A complete listing of the high priority improvements to Pinecrest Creek is provided in Table 1 with estimated construction costs.  A reference map to the locations is provided in Figure 4.  The NCC and the City are the sources of funds for the project. 


The majority of City funding will address the restoration of the Transitway berm ($115,000 - Reach 1: Sites 4, 5, 6) with the remainder contributing to restoration of erosion sites just downstream of a major storm sewer outfall and just upstream of a Transitway culvert, where significant desposition is occurring ($50,000 - Reach 3: Sites 24, 25, 26).  The identification of priority sites takes into account the level of risk to infrastructure as well as an understanding of how the adjustments made at one location may affect other locations along the stream.

 

Table1: Pinecrest Creek Priority Improvements and Estimated Construction Costs

Priorities

Reach

Sites

Budget

Immediate

1

4, 5, 6

$115,000

2

10, 11

$33,000

3

24, 25, 26

$50,000

4

19, 20, 21

$46,000

5

17, 18

$36,000

 

 

$280,000

6

13, 14

$26,000

7

1, 2

$42,000

8

7, 8, 9

$95,000

Sub-total

$443,000

Monitoring Required

9

3

$30,000

10

27, 28, 29

$127,000

Sub-total

$600,000

Capacity Concerns

Culverts

Sub-total

$85,000

Total

$685,000

 

The selected priority works on Pinecrest Creek have been compared with other works recommended in previous subwatershed studies including:

-     Carp River Watershed Study including Poole Creek and Feedmill Creek

-     Shirley's Brook - Watt's Creek Subwatershed Study

-     Shields Creek Subwatershed Study

-     Sawmill Creek Subwatershed Study.

 

Extensive works have been identified for Carp River, Poole Creek and Feedmill Creek, with funding to come from the proponents for Kanata West and the City (Carp River Restoration 903940).  City funding is being provided for the priority works recommended for Shields Creek (Stream Restoration 902203).  Works are planned for Sawmill Creek in 2008.  While works have been identified for Shirley's Brook and Watt's Creek, there are limited opportunities due to property ownership and otherwise relatively low urgency for the identified sites.

 

Based on the above review the works proposed for Pinecrest Creek have been determined to be the most effective investment for the available budget.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1:  Loss of Bank Material from Berm by the Transitway Between 2002 and 2005

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1:  Loss of Bank Material from Berm by the Transitway Between 2002 and 2005

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2:  Erosion Around Pathway Bridge Foundations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3:  Sedimentation of Box Culvert Reducing Capacity

Figure 4:  Pinecrest Creek Priority Sites

 

 

CONSULTATION

 

The National Capital Commission has a public consultation program for this initiative addressing the requirements of the Federal Environmental Assessment Process as the proponent for the works.

 

 

FINANCIAL IMPLICATIONS

 

The identified $160,000 is available in stream restoration account 902203.

 

 

SUPPORTING DOCUMENTATION

 

N/A

 

 

DISPOSITION

 

Planning, Transit and the Environment Department, Environmental Sustainability Division staff and Legal Services Branch will prepare an agreement with the National Capital Commission specifying requirements for the use of the funds.