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The Tatlow Creek revitalization project Milley, Susan Olucia 2003

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THE TATLOW CREEK REVITAUZATION PROJECT by SUSAN OLUCIA MILLEY B.F.A., The University of British Columbia, 1998 Dip., Art Hist., The University of British Columbia, 2000  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF  MASTERS OF LANDSCAPE ARCHITECTURE in THE FACULTY OF GRADUATE STUDIES (Department of Landscape Architecture)  We accept this thesis as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA November 2003 © Susan Olucia Milley, 2003  In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l l m e n t o f the requirements f o r an a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e a n d s t u d y . I f u r t h e r agree that permission f o r extensive copying o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may b e g r a n t e d b y t h e h e a d o f my d e p a r t m e n t o r b y h i s or h e r r e p r e s e n t a t i v e s . I ti s understood that copying o r p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t b e a l l o w e d w i t h o u t my w r i t t e n permission. . .  Department o f  L/(kj h^TA  f^E  Af?a-ll7~B<?T? JZ?F  The U n i v e r s i t y o f B r i t i s h Vancouver, Canada  Date -fXLTQRtt  Columbia  fO^QOO*)  T H E UNIVERSITY O F BRITISH C O L U M B I A ABSTRACT  THE TATLOW CREEK REVITAUZATION PROJECT by Susan Olucia Milley Chairperson of the Supervisory Committee: Professor Patrick Condon Department of Landscape Architecture  My project deals with one of the greatest resources on earth: water.  Increasing populations and land development requires  increased responsibility to preserve and enhance natural hydrologic processes as much as possible. But most often, current development and engineering practices do not recognize this growing responsibility, as urban water courses have been buried and / or culverted beneath the ground. Rainwater has been given an "out of sight out of mind" treatment as it is funneled into vast and expensive sewer system networks which leads to expensively and unnecessarily treated water, and destroys the natural recycling process of the hydrological system which recharges our water resources. One method of regenerating the hydrological system is by revealing, or 'daylighting' buried streams, and by implementing measures which will sustain them in their complex urban contexts. Streams within the Greater Vancouver area were once common. Now few streams remain in this urban landscape, and fewer yet are healthy enough to support their once-thriving fish habitats. Healthy streams and their environments create diverse habitats for ii  animals and plants, create pathways for movement in the larger landscape, reduce flooding of larger water bodies and reduce the amount of water being unnecessarily treated with sewage. Furthermore, streams give character and identity to the landscape and foster in people a greater sense of ecological recognition, community pride, value, and stewardship. My research is based on my belief that by re-introducing streams back into our urban fabric and designing effective stormwater design strategies to sustain them, we can greatly enhance and benefit both the ecological environment as well as our city communities. My thesis presents a model for daylighting Tatlow Creek; an urban stream in the Greater Vancouver district of Kitsilano. This model strives to: 1 ) Daylight Tatlow creek North under Point Grey Road, through Volunteer Park and into English Bay 2) Naturalize the riparian area 3 ) Restore the creek's base flow by suggesting short and longterm strategies for infiltration throughout the Tatlow Watershed. Tatlow Creek presents a unique opportunity in which to propose a viable system of green infrastructure which thoroughly integrates an urban park with its medium-density urban context. This system designs for a strategically planned and managed network of green spaces and corridors interconnected with an existing urban environment, which supports native flora and fauna, sustains water resources and natural hydrological processes, and contributes to the health and quality of life of the community. The district of Kitsilano currently possesses many positive aspects of sustainable ecological design, and as such presents a favourable practicability for adapting and retrofitting these with a long term design strategy for its entire  Ul  watershed.  This would then eventually connect with an expanded  green infrastructure network throughout the greater Vancouver region.  IV  TABLE OF CONTENTS Abstract  11  Table of Contents List of Figures  v  v  Acknowledgements Preface  " '  x  x  ''  FOREWORD  1  INTRODUCTION  2  1.1 The Importance of Dayligting  3  1.2 Methodology  4  1.3 Tatlow Creek 1.4 The Water Source 1.5 Site Analysis  6  1 2  1  1.6 Opportunities 1.7 Constraints  4  1 6  1 8  DESIGNS 2.1 Existing & Proposed 2.2 Creek Channel MASTER PLAN  2 1  2  8  4  2  V  2.3 Green-Grey Grid  47  2.4 Concluding Remarks  54  Bibliography  57  vi  LIST O F FIGURES  Figure 1 Regional Location of Tatlow Park V a n m a p : http://www.city.vancouver.bc.ca/vanmap/  6  Figure 2 Tatlow and Volunteer Parks C o u r t e s y of City of V a n c o u v e r E n g i n e e r i n g ; Reid Crowther & Partners  6  Figure 3 Aerial View of Tatlow Park, Looking North Copyright G e m i n i Photo, 1987  7  Figure 4 The Tatlow Watershed C o u r t e s y of C i t y of V a n c o u v e r E n g i n e e r i n g ; Reid Crowther & Partners  9  Figure 5 Section of a Perforated Infiltration Pipe D r a w i n g by A u t h o r  12  Figure 6 Detail of Green Corridors Map  Courtesy  of  City  of  Vancouver  Engineering;  Partners  Reid  Crowther  & 13  Figure 7 Aerial of Volunteer Park Copyright Schulhof Photography, 1997  15  Figure 8 Tatlow Park P h o t o g r a p h by A u t h o r  21  Figure 9 Tapwater entering Tatlow Creek Photograph by Author  ...  21  Figure 10 Existing Site Conditions Drawing by Author  22  Figure 11 Culvert under Point Grey Road Photographed by Author  23  vii  Figure 12 Proposed Creek Channel Drawing by Author  24  Figure 13 Proposed Lookout Drawing by Author  25  Figure 14 Vertical Structure of a Stream Corridor Drawing by Author  26  Figure 15 Native Plant List By Author  27  Figure 16 Creek Channel Cross-Section D r a w n b y A u t h o r ; Idea c o u r t e s y of N i c k P a g e  28  Figure 17 Creek Channel Plan D r a w n by A u t h o r  29  Figure 18 Slope Stabilization Techniques F i g u r e s 8-4 F r o m Flink, C h a r l e s A . a n d R o b e r t M. S e a m s , ( 1 9 9 3 ) G r e e n w a v s : A g u i d e to P l a n n i n g , D e s i g n a n d D e v e l o p m e n t , W a s h i n g t o n , D C , Island P r e s s .  29 Figure 19 Cross-Section with Toe-Slope Erosion Control D r a w n by Author, Structure c o u r t e s y of N i c k P a g e  30  Figure 20 Log Weir: C r o s s Section Drawn by Author  30  Figure 21 Log Weir: Plan and Long Profile D r a w n by A u t h o r  31  Figure 22 Existing Pipes Beneath Point Grey Road Drawn by Author  32  Figure 23 Section of Proposed Culvert Beneath Point Grey Road Drawn by Author  32  Figure 24 Perspective of Proposed Culvert/Bridge D r a w n by A u t h o r  33  Figure 25 Proposed Culvert/Bridge Fagade Drawn by Author  33  Figure 26 Proposed Culvert Dimensions and Structure Drawn by Author  34  Figure 27 Existing and Proposed Land Profiles Drawn by Author  36  Figure 28 Existing Contours Drawn by Author  35  Figure 29 Proposed Contours Drawn by Author  35  Figure 30 Proposed Creek Profile D r a w n by A u t h o r  36  Figure 31 Existing Irregular Creek Channel P h o t o g r a p h e d by A u t h o r  37  Figure 32 Cross-Section Site Map and Sections A to E F i e l d - M e a s u r e d a n d D r a w n by A u t h o r  38-40  Figure 33 Master Plan D r a w n by A u t h o r  42  IX  Figure 34 Section Plan with Sections A to F Drawn by Author  43-46  Figure 35 Curb Inserts Drawn by Author  48  Figure 36 Phase-In Plan for a Green-Grey Street Grid M a p C o u r t e s y of C i t y of V a n c o u v e r E n g i n e e r i n g ; R e i d C r o w t h e r & Partners  51  Figure 37 Plan and Section of a Green-Grey Street T y p o l o g y Drawn by Author  52  Figure 38 Green and Grey Street Profiles Drawn by Author  53  Figure 39 Catch Basin Retrofit Drawn by Author  50  Figure 40 Roadside Swale Drawn by Author  54  ACKNOWLEDGEMENTS  I would like to express my gratitude to the members of my committee for their support and guidance; Professor Patrick Condon, Dr. William Marsh, Nick Page and Maged Senbel.  XI  PREFACE  "Imported Sequoia trees add an air of dignity to Tatlow Park, where they tower above short-cropped grass and the remains of a long-ago-tamed stream. What remains of Tatlow Creek...is a tiny trickle of water—from a leaking water pipe— guided by rounded rocks carefully placed along its bank..." Gareth Kirkby, The Georgia Straight,  V a n c o u v e r , B C , M a y 29 , 1997 t h  xii  F  O  R  E  W  O  R  D  Tatlow Creek was scheduled to be daylighted. The idea came about in 1995 when the West Kitsilano Residents' Association formed a group to investigate the possibilities of such a project. In 1996, they, along with staff of the Vancouver Parks Board, City Engineering, and the Department of Fisheries and Oceans, had a meeting together to discuss the feasibility of this endeavour.  City engineers maintained  that indeed, storm water could be diverted back to a natural creekbed and tunnelled under Point Grey Road. implemented in 1997.  1  The project was set to be  1  S F U (n/d). A Strategic Concept Plan for A Model Sustainable Community in South-East False Creek, Simon Fraser University's Geography 449 class: Environmental Processes and Urban Development. http://www.sfu.ca/cedc/students/qeoaclass/qrnanbib.htm  1  INTRODUCTION  M y design goal in the Tatlow C r e e k Revitalization Project is to daylight the existing urban creek to its mouth at English B a y and to design for its sustained and healthy baseflow.  M y objectives in  accomplishing this goal are: 1. T o connect the existing creek c h a n n e l a c r o s s a busy road and to design a n adequate stream c h a n n e l and floodplain appropriate to the site conditions and 5-year stormwater volumes; 2. T o design a suitable riparian environment for the p r o p o s e d and  existing  creek c h a n n e l ; and  3.  To  suggest gradual  design  transformations which would turn the existing "hard, impervious and grey"  urban  infrastructure  into  a  "soft,  infrastructure.  M y d e s i g n s illustrate  retrofitted  an  into  existing  urban  pervious  and  a proposed stream  context,  in  partnership  green" channel with  a  suggested incremental retrofit and redevelopment of the watershed area to infiltrate stormwater which would then ensure a sustained creek baseflow.  T h i s would have additional benefits, including increased  stormwater quality and quantity control, and d e c r e a s e d d e p e n d e n c e o n sewers, culverts, and other expensive m e a n s of channeling water.  By  taking advantage of freely available natural p r o c e s s e s , I aim to m a n a g e precipitation a s c l o s e to where it falls a s possible and d e s i g n for a  2  "green infrastructure" to replace costly conventional infrastructure for stormwater storage, treatment and management. 1.1 The Importance of Daylighting Urban streams are an important but continually disregarded part of the landscape.  Daylighting streams provides many benefits,  including: Relieving under-capacity stormdrains and culverts; reducing runoff velocities thereby helping to prevent erosion, property damage and habitat loss; replacing old and damaged culverts with an open drainage system that is more accessible and can be more easily repaired and monitored thus reducing costs; diverting urban runoff from combined sewer systems before it mixes with sewage thereby reducing combined sewer overflows into English Bay and costly burdens on the lona treatment plant; improving water quality entering English Bay by exposing water to air, sunlight, vegetation and soil- all of which help filter and neutralize pollutants; creating fish, aquatic habitat and riparian habitat and linking greenway corridors for wildlife and pedestrian movement; providing active and passive recreational value for all ages; serving as an educational "nature laboratory" for urban schools; beautifying neighbourhoods; increasing property values; benefiting nearby businesses by attracting people to the area; creating job opportunities in building and maintaining the stream and park; building civic spirit and fostering community relationships; reconnecting people  to nature through the look, feel, smell and sound of o p e n water, riparian vegetation and aquatic and terrestrial life; fostering a s e n s e of "existential i n s i d e n e s s " by creating a vibrant and profound s e n s e of 2  place which people will be more likely to cherish and nurture.  3  Furthermore, the Greater V a n c o u v e r Regional District is expected to experience significant population growth over the next 50 years, and the increased urban densification and land development will increase the rate and volume of stormwater runoff. Consequently, this will have several effects including the need for upgrades and repairs to drainage infrastructure; increased risk of flooding; and increased pressure and d a m a g e to water quality and aquatic s y s t e m s .  4  1.2 Methodology T h e methodology I a m using for my design is that of "stormwater source control", a proactive a p p r o a c h which a i m s to capture rainfall at or near its source and subsequently return it to its natural hydrologic pathways by infiltrating it into the ground, and allowing the water to travel by interflow; subsurface pathways which flow laterally towards a  2  3  A meaningful term coined by Edward Relph in his book Place and Placelessness, 1976. List adapted from Pinkham,  R.  (2000). Daylighting:  New Life for Buried Streams.  Old  Snowmass, Colorado, Rocky Mountain Institute, i-iv. CH2MHILL (2002). Effectiveness of Stormwater Vancouver Sewerage & Drainage District, 2. 4  Source  Control.  Vancouver,  Greater  4  streambank or other depression which intersects the water table.  5  Alternatively, rainfall can be intercepted by vegetation, depression storage pockets for longer term infiltration, or it can be dispersed through the air by evapotranspiration. A target condition for stormwater source control methodology is for at least 90% of all rainfall to be returned to these natural hydrologic pathways or for it to be reused at or close to its source, since research shows that once the imperviousness of an area exceeds 10%, stormwater related impacts begin to occur. This is accomplished primarily by turning as much of 6  the watershed over to pervious and vegetated soil as is possible. Consequently, my designs include retrofitting streets, sidewalks, roofs and other impervious surfaces to either absorb or infiltrate water runoff, or to convey it to cisterns, dry wells, or other suitable vegetated infiltration pockets such as swales or wetlands.  This process  incorporates retrofitting existing engineered infrastructure such as curbs and catch-basins to accommodate these changes. Additionally, planting deciduous and evergreen trees will intercept rainwater yearround, to evaporate from leaves or more slowly infiltrate into the soil.  Marsh, W . M. (1998). Landscape Planning: Environmental Applications. New York, John Wiley & S o n s , Inc, 185. 5  6  CH2MHILL  (2002). Effectiveness  of Stormwater  Source  Control.  Vancouver,  Greater  Vancouver Sewerage & Drainage District, 1.  5  1.3 Tatlow Creek Tatlow Creek, or First Creek, is located in Tatlow Creek Park, a 1.41 hectare  • Qa*rt y  -1.  Kfciyr M  area  Mount Measant  [  I Kwrcd*  Figure  1  the  residential  *Ut. -ft I J.bjl ...  in  . ) '[ '  Kitsilano  '.Vtl-I.li*  mainly  district  (Figure  1).  of  The park  is bounded by Point Grey  S h o w i n g the location of Tatlow Park in V a n c o u v e r  Road on the North, West 3 Avenue  on  the  rd  South,  MacDonald on the East and  iGnnn  Bayswater  on the West  frWrtn n• 1*11  (Figures  I B QunHD!  iUlJJ UliliUJIE TIJJjJiJJii ITTT Tin  [MMigp  jLL  CWrfHrnfH  2,  3).  The entire  G I J W | P Tatlow Creek Watershed J LLii area (the catchment area)  j^##rH b=f?r#  was about 1.41 km , with its 2  Figure 2 Tatlow a n d V o l u n t e e r Parks  headwaters being close to Marguerite and Matthews avenues  (Figure 4 ) .  7  Like any natural stream,  the continual presence of water in Tatlow Creek was guaranteed by the gradual and steady conveyance of groundwater to it. This is water  7  P i t e a u A s s o c i a t e s (2000). R e s t o r a t i o n o f First C r e e k , T a t l o w P a r k , V a n c o u v e r ,  1.  6  which  has  infiltrated  and  filtered  through  the  ground,  resurfacing where the stream bed intersects the water t a b l e .  gradually 8  S u c h a steady supply of water to the  stream  would  thereby  constitute the C r e e k ' s baseflow during both dry a n d wet periods. According  to  an  old-time  resident in the a r e a , the creek c h a n n e l north of 4  H  t h  avenue was  in a d e e p gully until the 1 9 2 0 ' s w h e n it w a s filled in, partly with  Figure 3 Aerial View North  city garbage.  Furthermore, the  p r e s e n c e of s e d g e g r a s s in the intertidal z o n e along the shoreline indicated that a regular freshwater outflow w a s present, a n d like m a n y healthy streams, Tatlow C r e e k supported spawning fish populations, namely  salmon  and trout, until about  the  turn of  the  century.  9  Additionally, o n e of the primary goals of the S a l m o n i d E n h a n c e m e n t P r o g r a m of the Department of Fisheries a n d O c e a n s is the restoration of s a l m o n stocks. O n e of the main techniques which this e m p l o y s is  Marsh, W . M. (1998). L a n d s c a p e Planning: Environmental Applications. N e w York, J o h n Wiley & S o n s , Inc, 1 8 5 . > ' Piteau A s s o c i a t e s  (2000).  R e s t o r a t i o n o f First C r e e k , T a t l o w P a r k , V a n c o u v e r ,  1.  7  "the  removal  or  passage  around  manmade  a n a d r o m o u s s a l m o n a c c e s s to historic habitats"  barriers 10  to  allow  T h i s information  justifies the suitability of Tatlow C r e e k a s an appropriate candidate for daylighting.  1 0  F o y , M . ( 1 9 9 7 ) . R e s t o r a t i o n in the L o w e r M a i n l a n d . U r b a n S t r e a m P r o t e c t i o n , R e s t o r a t i o n a n d S t e w a r d s h i p in the  Pacific Northwest:  Are we achieving desired results?, Douglas  College, N e w Westminster, Q u a d r a Planning Consultants Ltd, 76.  8  Figure 4 T h e Original Tatlow Creek s t r e a m c o u r s e a n d w a t e r s h e d area (kidney s h a p e d outline). T h e s h a d e d area is the e n g i n e e r e d w a t e r s h e d c o n s i s t i n g of c u r b e d roads, c a t c h b a s i n s a n d p i p e s . T h e roman numerals indicate separate c a t c h m e n t areas.  Surficial sediments within the watershed are typical of the Greater Vancouver area; a mixture of glacial drift consisting of silty sediments broken up by pockets of sand, gravel and stony silt, and along the English Bay shoreline, sedimentary bedrock is exposed.  11  Geotechnical engineering surveys have shown that these sediments  11  Piteau Associates  (2000). Restoration  of First Creek, Tatlow Park, Vancouver,  2.  9  have  a  "relatively  low  permeability,  however  experience with  excavation in the area suggests that there are some localized pockets of more permeable sand units in the area". Indeed, numerous studies 12  of soil characteristics within the greater Vancouver area suggest that there exist enough pockets of sand and gravel interspersed within the sub-surface sediments as to ensure a regular infiltration capability. In one case study conducted by the James Taylor Chair, stormwater infiltration in Amble Greene, Surrey, was successfully achieved using natural infiltration methods, in a soil profile comprised of the same layers as those found in the Tatlow Creek watershed: "...a layer of topsoil, which varies in thickness from 0.1 metres to 0.5 metres, above a fairly compacted layer of gravely sandy soil, which reaches depths of 2.0 metres. Immediately below this gravely soil, is a more impervious layer, which is referred to as 'hardpan' and composed of fine sand and silty-clay." Moreover, subsequent evaluation of the site 13  to date claims: "Overall, the project has been successful at minimizing stormwater runoff from the site. And, despite the underlying hardpan layer impeding the flow of water to the deeper water table, the soil layer above the hardpan layer acts effectively as a reservoir during  Condon, P. (2000). Amble Greene, District of Surrey, B C Alternative Stormwater Management Systems: Technical Bulletin. Vancouver, T h e J a m e s Taylor Chair in Landscape & Liveable Environments, 2. 1 3  10  saturation periods.  It appears that these 2 metres of generally  compacted soil have adequate storage capacity for even the 100-year storm. (There have been two hundred-year storms since the project was  built).  There are no discharges of stormwater from the  infiltration-based portions of the site. Due to the effectiveness of the stormwater system at Amble Greene, ninety five percent of the developer's contributions for [conventional] downstream drainage facilities were rebated 2 years from the end date of construction."  14  Further characteristics of the Tatlow Creek hydrogeology were described in a report for the city of Vancouver by Klohn-Crippen Consultants Ltd., which attributed the watershed as being within a "groundwater discharge zone". These are zones in which there is a "net migration of groundwater toward the ground surface, which results in shallow water tables and an all-year-round discharge to surface channels, which typically sustains creek baseflows. then  urban  development,  including  house  and  Since  infrastructure  construction, has likely created a deeper water table in many places.  15  Given that the area is within a groundwater discharge zone, in addition to the interspersed pockets of permeable sand within the 1 4  1 5  Ibid, 3. Piteau Associates (2000). Restoration of First Creek, Tatlow Park, Vancouver, 3.  11  ground a n d a " c o n s i d e r a b l e northward groundwater g r a d i e n t " site  provides  the  b a s i s for  a functioning  creek  with  16  the  sustained  b a s e f l o w s a n d a n opportunity to revitalize its o n c e - plentiful s a l m o n population, if appropriate d e s i g n s c a n be retrofitted into the existing urban context. 1.4 T h e W a t e r S o u r c e By implementing stormwater s o u r c e control methodology into my design, I aim to restore a sustained baseflow to Tatlow C r e e k .  To  create an immediate, short-term baseflow in the creek however, this involves employing the city's pipe-separation project.  The Vancouver  engineering department is currently changing the city's s e w e r s y s t e m from  a combined  s y s t e m (where  VEGETATED PERMEABLE SURFACE (MINIMUM GRASS)  storm  and sanitary s e w e r  flow  R O C K FOR CURB ^ — -  H20  PERFORATED PIPE WRAPPED IN FILTER FABRIC  •~T~  . PIPE TO CATCHBASIN OR OTHER STORAGE/FILTRATION AREA CATCHES FIRST-FLUSH WATER A N D OVERFLOWS  PERFORATED INFILTRATION PIPE  Figure 5  16  Ibid., 3. 12  together in one pipe) to a separated system with pipes for each. Their goal is to remove all combined sewers by 2050. My design proposes 17  to only lay the sanitary sewer pipe, and replace the storm pipe function with a network of perforated pipes which allow rainwater immediate infiltration capability  (Figure 5).  Such pipes are to be located under roadside swales and along the edges of impervious surfaces which generate sheet flow (driveways, tennis courts...). If and when flooding occurs, these swales, pervious streets and green corridors are designed to act as existing roads do- to store or channel and convey excess water to a safe flooding area. In this case, such a place could be a park, other greenspace, wetland,  E  N  G  L  I  S  H  ^  or even a larger body of water such as English Bay (Figure  6).  In  the Vancouver region, swales can absorb 24mm of water per day during winter, and water will enter the perforated pipes only after the  „. Figure 6 Detail s h o w i n g green c o r r i d o r s c o n v e y i n g e x c e s s stormwater to E n g l i s h  swale  17  has  become saturated. B a y  City of Vancouver (2003). Broad City Initiatives, http://www.city.vancouver.bc.ca/sustainability/initiatives.htm.  13  Swale sizes can also be varied to intercept interflow farther beneath the ground.  18  Through these means, a more immediate source of  infiltrated water will recharge Tatlow Creek.  However, as the  changeover to infiltration pipes and a green infrastructure network is gradual and piecemeal, the creek may not be able to maintain baseflow in the short-term.  In this case it may be necessary to augment the  infiltrated water flow with tap water from the existing GVRD pipe, and to employ a shut-off mechanism to ensure that the creek does not receive a disproportionate volume of water in relation to its designed capacity. This reinforcement would then be phased out over time, as more and more of the watershed area will be connected with green infrastructure which will absorb, filter, and channel water which will recharge the creek and ensure it receives a naturally sustained baseflow. 1.5 Site Analysis Currently, the Tatlow Creek Watershed is comprised of medium density residential and commercial areas. The landscape as such is made up of various built layers including roofs, roads, driveways, foundations and pipes, which make up a large percentage of impervious areas. Beneath the streets, the integrated network of sub-  1 8  Condon, P. (2003). Green Municipal Engineering for Sustainable Communities, http://vwvw.sustainable-communities.agsci.ubc.ca/bulletins/municipal_engineer_article.pdf.  14  surface stormdrains function to override the sites' natural hydrological p r o c e s s e s a n d is delineated by the large s h a d e d a r e a in figure 4. T h i s area represents the engineered system of c a t c h b a s i n s a n d pipes, a n d it c a n be s e e n that all of this contributes to a very large percentage of i m p e r v i o u s n e s s a s stormwater is tunneled a n d directed through  the  system to the waste treatment plant, or spills out with raw s e w a g e via overflow pipes into English B a y during large storms. Controlled in this way, stormwater has no o c c a s i o n to meet the ground a n d therefore cannot recharge the groundwater which subsequently f e e d s into a n d maintains stream baseflows. A  n u m b e r of g r e e n s p a c e s dot the watershed a r e a , including  those in schoolyards, fields, boulevards, a n d most notably the unique pocket parks nestled between the prime residential properties strung along the English B a y shoreline.  ;,_„..,•'-•'""  "  O n e s u c h g r e e n s p a c e is Volunteer  ENGLISH BAY  F i g u r e 7 View of Volunteer Park, l o o k i n g s o u t h t o w a r d s Point G r e y Road  Park, which is located directly north from Tatlow Park across Point Grey Road (Figure  7).  Historically, the route of Tatlow Creek ran through the west side of this park to its mouth at English Bay, and as an existing greenspace, Volunteer park makes a predictably appropriate location through which Tatlow Creek should continue to flow. 1.6 Opportunities Though urban development in the area increased imperviousness and disrupted the natural hydrological recharge capabilities of the ground in the watershed, the site nevertheless presents many opportunities for achieving the gradual transformation of the hard, grey, impervious infrastructure into a soft, green, and pervious system to replenish creek baseflows and provide for a more sustainable, costeffective arrangement to create urban and ecological revitalization and rehabilitation.  One such opportunity exists through the previously  mentioned pipe-separation construction undertaken by the City of Vancouver, which provides the capability to  replace the old,  conventional pipe systems with the new green infrastructure which lets stormwater permeate into the ground or travel through a networked series of trenches to specific green, "flood-out areas" which can also provide biofiltration for the water. When taking advantage of the many existing greenspaces and edges in the area, they can provide places 16  for creating wetlands which serve as areas of stormwater detention, filtration, valuable habitat, as well as spaces for learning. This additionally presents increased long-term savings from costly pipe laying and curb construction when integrated into a larger arrangement with green roads. Another opportunity for implementing the green network is with regard to the significant  population growth which the Greater  Vancouver Regional District is expected to experience over the next 50 years.  As Greater Vancouver's population density increases, many  older residential and commercial buildings will need to be re-built, renovated or retrofitted.  Consequently, these buildings could be  integrated to support the green infrastructure system. Minimally, roof leaders and gutters could be disconnected from the storm sewer system and otherwise diverted into swales and wetlands for biotreatment and infiltration. Designs for development for zoning and land use could be reconciled and structured in accordance and compatibility with the objectives of the new, green, goals and objectives, and local codes such as those for plumbing, building, street design, drainage and property management could also be modified or eliminated, if incompatible.  In order to assure watershed-wide restoration and  redevelopment goals, a coordinating procedure should be set up to review redevelopment plans to guarantee the success of ecosystem 17  development objectives and to verify that projects do not contradict each other.  Education is vital to such an initiative, and developers,  citizens, and city officials would work more effectively towards realizing long-term goals if broader-scale linkages within the system are better understood.  19  Undoubtedly, significant re-development of an entire watershed area will take many years as such progress is incremental. Nevertheless, the important part is to begin, and my designs aim to present the beginning of such a change. 1.7 Constraints Creating a soft infrastructure in a hard environment creates the issue of how to deal with the existing layers which more often than not impeded such construction and retrofitting.  Designing a bridge  underneath Point Grey Road, for instance, necessitates the retrofit of a structure which would be able to circumvent, yet incorporate, the large utilities beneath it. Such construction naturally accrues an initially large pricetag, but the cost of this retrofit coupled with a green infrastructure plan, would be subsidized in the long run, as costs associated with conventional "grey" construction are thereby reduced or eliminated.  1 9  Ferguson, B. (1999). Re-Evaluating Stormwater: The Nine Mile Run Model for Restorative Development. Snowmass, Colorado, Rocky Mountain Institute, 29.  18  Another apparent constraint lies within the fact that this is, after all, a constrained urban area, and designing for a healthy creek requires a substantial riparian zone and floodplain. The Department of Fisheries and Oceans defines a substantial riparian zone as "at least 15 metres from each side of the watercourse, from the high water mark, in a residential/ low density area." Because the largest distance between 20  high water mark and urban edge in my design is 15 metres, this is technically a constraint.  However, I believe that my proposed  landscape designs and infrastructure retrofits filter and convey water more effectively than a more substantial buffer would in a 'natural' creek situation.  As a result of these interventions, my design  accounts for the loss of these extra metres of riparian area. A more physical drawback in designing the proposed creek channel through Volunteer Park relates to the topography and geology of the site. The north end of the park is flanked by a 3.5 metre high bluff, and the erodible sedimentary makeup of the soil prevents the channel from lying at more than a 10% grade without significant armouring. This limitation has been taken into account in my ensuing channel design.  2 0  Chilibeck, B. (1993). Land Development Guidelines for the Protection of Aquatic Habitat, Ministry of Environment, Lands and Parks, Integrated Management Branch, 18.  19  20  D E S I G N S 2.1 Existing & Proposed Tatlow Park is a picturesque park within a residential neighbourhood. It includes some of the city's oldest Sequoia trees, and white birches line its gently sloping grasscovered banks  ( F i g u r e  8).  It is a quaint park straight out of a fairy tale, and as such is popular for weddings and family F i g u r e  8  T a t l o w  picnics.  P a r k  21  However, the  park does not represent a natural, functioning stream environment. Tatlow creek is an existing 55 metre section within the park, and is fed by tap water during the F i g u r e  9  T a p  w a t e r  e n t e r i n g  T a t l o w  C r e e k  Douglas Paterson, personal communication, January, 2003, UBC.  21  summer months which enters the creek by way of a GVRD pipe  (Figure  9). This is noted as the spot where the creek begins, in figure 10. From this contrived source, the clear, chlorinated water flows tentatively amongst strategically placed stones through the irregular, mudlined channel to finally exit the park, intermittently, under a culvert adjacent to Point Grey Road  (Figure 1 1 ) .  It is speculated that the water eventually discharges from EXISTING SITE CONDITIONS  the old culvert  Figure 1 0  22  into English Bay. This culvert is shown in figure 10 as at the location 22  where the creek ends. Fortunately, the location and site conditions of Volunteer and Tatlow parks present some good prospects for a daylighting connection. The major obstacle to attaining this goal however, is Point Grey Road and the deeply embedded infrastructure that lies beneath it. To resolve this complication Figure 01  Culvert under Pt. G r e y R d .  designed a culvert-bridge, which is seen in the resulting proposed creek channel diagram  (Figure 12).  This  diagram shows my proposed 60 metre channel length from the culvert, which first turns 5 metres east of its former location in Tatlow Park to run perpendicular under Pt. Grey Road into, and through Volunteer Park to its mouth at English Bay. At grade, I propose a connecting pedestrian path across the busy street to allow easier access to and from both parks. Other significant changes to the parks involve Piteau Associates ( 2 0 0 0 ) . Restoration of First Creek, Tatlow Park, Vancouver, 2 .  23  widening a n d stabilizing the entire creek c h a n n e l to m a k e allowance for increased a n d continual annual flows. Furthermore, I a d d e d a circuitous pedestrian path through Volunteer P a r k and connected both sides of the p r o p o s e d creek with a wooden pedestrian bridge, to be d e s i g n e d in the s a m e spirit a s those existing in Tatlow Park. T h e paths within the park PROPOSED CREEK C H A N N E L  /  N  lead to a Figure 12  .  ,  raised, w o o d e n platform lookout  (Figurei3)  which takes advantage of the site's fantastic 24  views of downtown Vancouver, the north shore mountains, and the sunset, a s well a s of the creek mouth and channel. T h e structure is draped with a native, coastal honeysuckle w h o s e roots, and the roots of shrubs planted beneath it, provide extra slope stability for the north-east U  corner a n d e d g e of the park, which will r e m a i n steep. At the creek's mouth I a m proposing  Figure 13 T h e L o o k o u t  a s p a c e for an estuary, which will provide a transitional e d g e for s a l m o n a s they adjust for the freshwater environment. All of these s p a c e s , including those within Tatlow park, are l a n d s c a p e d with native plants in s u c h a w a y a s to create a specific plant gradation.  25  This gradation is m a d e up of an overstorey, understorey a n d groundcover, a n d not only e n s u r e s a thick riparian e d g e to the creek which functions to deter a c c e s s by people and d o g s , but also creates valuable habitat for birds and other small m a m m a l s , creatures and o r g a n i s m s which typically live in and around streams  ( F i g u r e 14).  The  continual a n d growing p r e s e n c e of this flora a n d fauna helps to maintain a healthy creek and creek environment, which c a n support thriving a n d sustained fish populations.  VERTICAL STRUCTURE O F A STREAM C O R R I D O R F i g u r e 14  A s previously mentioned, the planting plan is b a s e d o n a native assortment of d e c i d u o u s a n d evergreen plants, a n d include m a n y 26  which were historically present in the a r e a . A c c o r d i n g to o n e s o u r c e , V a n c o u v e r w a s forested with overstories s u c h a s D o u g l a s Fir, C e d a r and W e s t e r n  Hemlock which towered  approximately 1000 years o l d .  2 3  over 99 metres,  and  were  T h e s e and other plants, m a n y of t h e m  berries, c o m b i n e d to form a rich and varied environment which I intend to emulate a s much a s possible in my design  OVERSTORY  (Figure 15).  UNDERSTORY Evergreen  Evergreen  Western Red Cedar thuja plicata Douglas Fir Pseudotsuga menziesii Western Hemlock Tsuga heterophylia Pacific Madrone Arputus mennesii Shore Pine Pinus contorta var. Contorta  Pacific Rhododendron Rhododendron macrophyllum Evergreen Huckleberry Voccinium ovatum Tall Oregon Grape Manonia acquitolium Silk-Tassel Bush Garrya emptied  Deciduous  Deciduous  Big Leaf Maple Acer macrophyllum Greene's Mountain Ash Sorbus scoputino Vine Maple Acer circinatum Paper Birch Betulo papyritera Pacific Crabapple Malus fused  Thimbleberry Rubus parviflorus Salmonberry Rubus chamaemorus Red Elderberry Sambucus rocemosa O c e a n Sprdy Holodorus discolor Nootka Rose Rosa nutkana Pacific Ninebark Physocarpus capitatus Cascara Rhamnus purshiana Servceberry Ameianchier alnifolia Red-Osier Dogwood Cornus stolonifera Hardhack Spiraea douglassi ssp. Douglass! Western Trumpet Honeysuckle Loncera ciliosa  GROUNDCOVER Evergreen Salal Gaultheria shallon Oregon Grape Mahonia nervosa Kinnickinick Ardostophyllos uvo-ursi Western Sword Fern Polystthum munitum Creeping Snowberry Gaultheria hispiduld St, John's Wort Hypericum calycinum WETLAND (To withstand both drought and inundation) Western Red Alder Alnus rubra Paper Birch Betula papyriferd Redtwig Dogwood Cornus stolonifera Cattail Typho lotitolia Common Rush Juncus eftusus Dense Sedge Carex densa  ESTUARINE  •'Ii,'!  Saltgrass Distlchlis Saltwort Salicornia Eelgrass Zostero marina Sweetgale Myricogale Lyngebye's Seage Carex lyngbyei Bulrush Scirpus californicus Broad-leaved Cattail Typha latifolia  Native Plant List  Figure 15  23  Macdonald, B. (1992). Vancouver: A Visual History. Vancouver, Talonbooks, 10.  27  2.2 C r e e k C h a n n e l T h e creek channel depth and width is b a s e d upon calculations for a 5-year storm, with a maximum flow velocity of  1.80m /second. 3  24  T h e s e n u m b e r s , however, represent the m a x i m u m velocity from a n immediate  stormwater  discharge from  the  engineered  catchment  s y s t e m s I a n d II in figure 4. This refers to water c o m i n g directly from the  stormwater  pipe  to  the  creek.  With  my  proposed  green  infrastructure d e s i g n , however, s u c h a s u d d e n velocity of water would not be attained since stormwater must first infiltrate through the ground  I 2M  F i g u r e 16  Creek Channel Cross-section  and gradually reach the creek by w a y of interflow. these  numbers  is therefore  a "safe" target  M y d e c i s i o n to u s e  maximum  based  on  predicted peak flows for a direct water discharge to the creek. 2 4  A a r o n Grill, C i t y o f V a n c o u v e r E n g i n e e r i n g , p e r s o n a l c o m m u n i c a t i o n , J u n e 5, 2 0 0 3 .  28  Figure 17 Creek C h a n n e l Plan  Moreover, in order to protect against erosion of the b a n k s w h e r e the creek d e s i g n obliges the slope to be steep, I h a v e suggested two methods of slope stabilization; live cuttings and live cribwall  (Figure 18).  Figure 18 S l o p e stabilization t e c h n i q u e s  A n o t h e r w a y of strengthening a terraced bank floodplain is by constructing a "toe" using rocks and c o b b l e s  (Figure 1 9 ) ,  or, if the s l o p e 29  isn't too steep (<50%), then stability c a n be a c c o m p l i s h e d simply by using rocks and logs in conjunction with various plant layers.  CROSS-SECTION WITH TOE-SLOPE EROSION CONTROL Figure 19  In a n effort to keep the creek c h a n n e l below a 1 0 % gradient through the softer sedimentary soil layers in Volunteer Park, I h a v e designed  a  Figure 20 L o g weir: c r o s s - s e c t i o n  30  channel. These could be fashioned of rocks or logs, and function to keep water velocity in check (Figures  20,21).  Figure 21 L o g weir: Plan, a b o v e a n d L o n g Profile, below  In order for the creek to successfully cross from Tatlow into Volunteer Park, it needed to cross under Pt. Grey Road, and I had to design around the existing infrastructure beneath it. Under the typical 30 cm road base, there lies a 60 cm deep utilities box with water, gas and hydro pipes. Below that is the main GVRD combined sewer-water trunk pipe, 1.8 metres in diameter  (Figure 22).  31  Figure 22 Showing the existing pipes beneath Pt. Grey Road  Accordingly, I am proposing a concrete T-shaped culvert which functions as a suitable bridge over the creek while simultaneously suspending the hefty infrastructure above it. The culvert would be integrated with my green infrastructure plan by including swales at both sides which filter stormwater runoff before allowing it to enter into the creek by way of  attractive  spouts  on  either side of the  structure  (Figures 23-25). Section of culvert beneath Point Grey Road  Figure 23  32  Figure 24 P e r s p e c t i v e view of p r o p o s e d culvert/bridge with biofiltration s w a l e s a l o n g Point G r e y Road  T h e d i m e n s i o n s of the culvert itself h a s the s a m e b a s e width a s the creek c h a n n e l , and a height of 1 metre to allow for light a n d air  Culvert dimensions  Culvert interior with grouted stone baffles Figure 26  penetration  (Figure  26).  Furthermore, the culvert h a s stone baffles  34  grouted in place on its base, to prevent the increased velocity which can o c c u r in smooth channels. T h e culvert c a n h e n c e be s e e n situated in its overall context, in the existing and proposed land profile  (Figure 27).  A s the existing Tatlow  C r e e k is, o n average, a depth of 3 metres below top of bank, the c h a n g e in depth to a c c o m m o d a t e the culvert beneath the road utilities w a s not of c o n s e q u e n c e . A s the land profile in figure 2 7 s h o w s , the most significant c h a n g e occurs to the grading within Volunteer Park, which is intended to minimize the distance between the top of the proposed bank and the creek, a s well a s to provide for a gently sloping c h a n n e l gradient. T h e s e contour c h a n g e s are evident in figures 28 a n d 29.  Figure 28 E x i s t i n g c o n t o u r s  F  i  g  u  r  e  2  9  Proposed contours and channel  35  A s noted in figure 2 9 by the d a s h e d circles, the r e m o v a l of existing trees w a s required.  Superfluous earth produced by the land grading  p r o c e s s could then be used to build up the s i d e s of the existing creek to conform to the addition of the n e w creek c h a n n e l , or u s e d in urban agriculture projects a n d community g a r d e n s in the neighbourhood. T h e p r o p o s e d creek profile s h o w s the creek gradient a n d 7 weirs s u g g e s t e d along its length  (Figure 30).  At the beginning of the creek in Tatlow P a r k I h a v e p r o p o s e d a wetland w h i c h traps a n d filters receiving water before slowly draining creek. come nearby  Such from  it  into  water the  the  could  roofs  of  r e s i d e n c e s , sheet-  30 cm width flow from the adjacent tennis courts,  and  infiltrating  the  constantly  water  from  roadside s w a l e s . S i n c e Tatlow C r e e k is  Figure 31 Irregular creek c h a n n e l  not  a  normally  functioning  stream, its c h a n n e l is likewise not representative of s u c h .  A s it  currently lies, the c h a n n e l widens from a sprawling 5 metres, d o w n to a 37  puny, g r a s s c o v e r e d 30 c m with depths from a m a x i m u m 2 9 c m to 9 cm,  respectively  (Figure  31).  T h e existing c h a n n e l h e n c e requires regularization to stable  flow  support  and  a  adequate  depth, a n d to allow for fish passage. I then m e a s u r e d c r o s s sections A to E of the creek in Tatlow P a r k to establish a more accurate depiction of the existing profile. S e c t i o n s A  to  E  represent  profiles a s they  these  could  be,  with my s u g g e s t e d c h a n n e l design CROSS-SECTION SITES Figure 32  t  h  e  m  superimposed (  R  g  u  r  e  3  2  a  n  d  on c  r  o  s  s  sections A-E).  38  CROSS-SECTION A  CROSS-SECTION  C  CROSS-SECTION D  U p to this point, I have modified and connected the existing creek channel a c r o s s Point G r e y R o a d and d e s i g n e d a n adequate stream c h a n n e l a n d floodplain appropriate to the site conditions a n d 5-year stormwater volumes. I have suggested a suitable riparian environment for the proposed and existing creek c h a n n e l and have initiated the foundation for gradual design transformations which would turn the existing "hard, impervious and grey" urban infrastructure into a "soft, pervious a n d green" infrastructure,  which would  subsequently  re-  charge the creek. Figure 33 is the master plan which illustrates t h e s e c h a n g e s in totality.  41  Figure 33  42  T h e following sections (A-F) illustrate the proposed character a n d landform of the site and correspond to the marked locations o n the master plan a r e a s h o w n in figure 34.  F i g u r e  34  43  -t-  -t-  2.3 Green-Grey Grid Until now I've begun to suggest designs for realizing a creek baseflow using swales and wetlands.  The master plan shows additional  changes which include vegetated, grass or gravel swales on every road, and a "green-grey grid" street network which forms the basis of the green infrastructure system. This endeavour instigates a long-term watershedto-region strategy for sustaining not only our creeks but a healthy hydrological system, water reservoir, ecology and society. Sustainable fish habitats are dependent on functional watershed processes. Certainly, "If fish could talk and we asked them, "Which of our engineering techniques have had the most negative impact on fish habitat?", my guess is that the answer would be paving"  25  Indeed the green-grey grid is an attempt to mitigate, and over time eliminate, the harmful effects that paving causes on the watershed and ecology. - The network is comprised of a grid of streets; some green, some grey as the name suggests. Green streets contain the following characteristics: they are 100% permeable; they are narrower than grey streets, pedestrian oriented and as such vehicle access (with the  Bomford, J . (1997). C a n Fish Habitat Be Engineered? Urban Stream Protection, Restoration and Stewardship in the Pacific Northwest: Are we achieving desired results?, Douglas College, Quadra Planning Consultants, Ltd, 63.  47  exception of e m e r g e n c y vehicles) is limited or d e n i e d ;  26  a n d they are  highly vegetated. B e c a u s e of these particular qualities, green streets are generally, but not exclusively, residential streets and lanes. G r e y streets, on the other hand are the busier arterial a n d collector streets which permit vehicle a c c e s s , a n d are permeable in that stormwater runoff is directed to s w a l e s a n d infiltration strips along both sides of the streets. F o r streets where construction (such a s pipe-separation) is not taking place a n d curbs cannot be readily eliminated without e x c e s s i v e cost, such  streets  retrofitted inserts  could  with which  be curb  permit  runoff to enter the linear SWaleS (Figure 35). ASPHALT  R O A D :  C O L O U R E D O R  OTHER  GLASS,  TILE,  Mutually,  R E C Y C L E D  these  IVIAItKIAL M ATERIAL C U R B INSERTS Figure 35  green  a n d grey  streets  aim to infiltrate all of the  stormwater which falls onto paving, or a n y other road surface.  Taken  together with residential a n d c o m m e r c i a l stormwater re-use, in the form of roof g a r d e n s or cisterns for instance, or re-direction to nearby wetland pockets a n d swales, 9 0 to 1 0 0 % of all stormwater c a n be infiltrated a n d  1  T h e Netherlands' woonerf  is an example of such a narrow, generally residential, pedestrian-  oriented street, but may not be permeable.  48  in this way can subsequently re-charge the baseflow not only in Tatlow Creek, but in other daylighted urban streams as well. Such a network would be phased in over time, and on a regional scale connected to commercial and industrial districts and other, larger greenspaces and greenways in and around parks, schools, hospitals and the like. Figure 36 shows a 10-year, 25-year and 100-year recommended phase-in plan for the grid, while figure 37 proposes an example green-grey street pattern within the Tatlow Creek watershed and its corresponding street section. Figure 38 then provides detailed examples of each proposed street typology. As previously mentioned, my designs also include retrofitting existing engineered infrastructure such as curbs and catch-basins to enhance the green-grey grid.  As my design proposes a network of  perforated pipes which allow rainwater immediate infiltration capability, the stormwater runoff has 3 options: 1. going straight into the ground 2. going into a perforated pipe which leads to a wetland or other biofiltration pocket, or 3. going through a perforated pipe into a catch-basin which is specifically designed for filtering first-flush runoff; that which occurs in the first 1-1.5  hours of a storm, and which contains the  highest  49  concentrations of pollutants like oils, s o a p s , metals, fertilizers, pesticides and s e d i m e n t s .  27  After filtering through the catch-basin, the water would then carry on through perforated pipes to infiltrate into the ground to a creek or wetland (Figure 39).  S u c h pipes are to be located under roadside s w a l e s a n d along  the e d g e s of impervious a r e a s w h i c h cannot otherwise be m a d e permeable, with drainage holes that would allow a s l o w drip of water to go through, but REMOVEABLE GRATE  not a fast flow PERFORATED PIPE >E  in OVERFLOW TO ESIOFILTRATTON AREA  a  large  storm,  thus  METALS FILTER  avoiding  SEDIMENT A N D GREASE TRAP PERFORATED PIPE TO CREEK  contaminants  C A T C H BASIN RETROFIT: S T O R M PIPE M O D E L  from  leaking  through  Figure 39  (Figure 40).  (continued on page 54)  Kulzer,  L.  R.  (1997). Stormwater  Quality  Control.  Urban  Stream  Protection,  Restoration  and  S t e w a r d s h i p in t h e P a c i f i c N o r t h w e s t : A r e w e a c h i e v i n g d e s i r e d r e s u l t s ? , D o u g l a s C o l l e g e , N e w Westminster, Q u a d r a Planning Consultants Ltd, 4 9 .  50  LU  EE  o CL LU  CT  I —  CO  0  O cr  cr  i— CO  >LU  cr 0  a. ii  00 CO  3  O)  R O A D S I D E SWALE F i g u r e 40  Implementing  s u c h a broad-scale restructuring in a d e v e l o p e d  urban context is no doubt a long-term strategy. 2.4 C o n c l u d i n g R e m a r k s In addition to the benefits I have previously mentioned, executing the green-grey grid s c h e m e and allowing c r e e k s to c h a n n e l stormwater would m e a n a long term cost savings, e v e n though the initial cost of daylighting the creek would be large; at least $ 6 0 0 per m e t r e . catch-basin retrofits and maintenance may prove to be costly.  And  28  But in  the long term, these c o s t s would be s u b s i d i z e d by other s a v i n g s . Simply  having  stormwater  uselessly treated  in  the  lona  Island  W a s t e w a t e r Treatment Plant, only to have it p u m p e d out into English Bay,  2 8  is  a  cost  of  approximately  $70  000  per  cubic  foot  per  S F U (n/d). A S t r a t e g i c C o n c e p t P l a n for A M o d e l S u s t a i n a b l e C o m m u n i t y in S o u t h - E a s t F a l s e C r e e k , S i m o n F r a s e r U n i v e r s i t y ' s G e o g r a p h y 449 c l a s s : E n v i r o n m e n t a l P r o c e s s e s a n d U r b a n Development. http://www.sfu.ca/cedc/students/qeoqclass/qrnap37.htm  54  year. Furthermore, the GVRD would save an additional amount from superfluous tap water which runs through Tatlow Creek during the summer months. The cost of water in 2003 is a flat rate of $271.00 per year for single family dwellings, and the metered rate for multi-family residential, industrial or commercial customers is approximately 46.3 cents per cubic meter. The re-use of water using cisterns and other 30  means of storage could save money to these groups as well. Moreover, the cost to the city, and thus to the taxpayer, for laying water pipe infrastructure is approximately $150.00 per linear metre.  31  This cost however does not reflect the additional fees for labour and materials such as asphalt and fuel. Additionally, further costs are saved since green roads do not require re-paving or considerable maintenance, and even more money would be saved by not constructing curbs. Perhaps needless to note given the location of the creek, but as a result of the enhanced aesthetic and recreational nature of the proposed site, property values would rise in the area, and taxes would decrease as infrastructure maintenance costs would be lowered. 2 9  3 0  3 1  ibid. Vancouver Engineering Water Rates: Cost of Water 2003. http://\AMw.citv.vancouver.bc.ca/enqsvcs/watersewers/water/rates.htm Condon,  P.  (2003).  Green  Municipal  Engineering for  Sustainable Communities,  http://www.sustainable-communities.agsci.ubc.ca/bulletins/municipal_engineer_article.pdf.  55  Further, because landscaping would be carried out to emulate what would be found in a regional native forest setting, the otherwise high maintenance costs for lawn-mowing and applying fertilizers and pesticides would be reduced, or eliminated. In all, these costs add up to a significant amount which should not be overlooked when assessing the true value of daylighting creeks and applying green infrastructure designs. Throughout my thesis I have intended my designs to suggest an overall vision for an urban environment, in which the preservation of water and the significance of creek daylighting is central. I hope that I have achieved my design goal and objectives, designed an integrated and convincing system which not only revitalizes out hydrological and ecological systems, but also implements successful measures which will sustain them in their complex, densifying and transforming urban context.  56  BIBLIOGRAPHY  Bomford, J. (1997). Can Fish Habitat Be Engineered? Urban Stream Protection, Restoration and Stewardship in the Pacific Northwest: Are we achieving desired results?, Douglas College, Quadra Planning Consultants, Ltd. CH2MHILL (2002). Effectiveness of Stormwater Source Control. 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