Sustainability and the Delaware Waterfront Connecting Philadelphia back to the Delaware River: Guiding Strategies to Integrate Development with Natural Systems
Sustainable sites marry natural processes with built systems to achieve balanced environmental, social and economic outcomes that better the quality of life and long-term health of Philadelphia’s communities. As Philadelphia invests in the longterm sustainability of its waterfront, restored ecosystems should be a large part of the new infrastructure. The strategies outlined within this report place a new value on the waterfront and reposition natural processes as partners of redevelopment. With this approach, environmental problems are addressed with long-term solutions, which provide services that give back to the City of Philadelphia in multiple ways. Much of the challenge is to rethink old attitudes about public space and collective assets. For instance, as the largest collective area of public land, streets can become more than merely functional devices for traffic – imagine a productive street that contributes to water quality, air quality, public health, and social capital. Like streets, the riverfront can be reinvented as a collective asset rather than a privately owned commodity – we all stand to gain from increased habitat, river recreation, education, alternative energy sources, and alternative solutions to our over-burdened sewer system. These are choices we need to make to ensure that the Delaware Waterfront remains the vessel of Philadelphia’s collective desires, ambitions, and vision.
New planning mechanisms are underway for the Delaware River that will begin to formalize the integration of ecology with development: a Riverfront Zoning Overlay to direct land uses; PWD stormwater management plans to address combined sewers; and PCPC public infrastructure plans for the North Delaware Riverfront, among others. Development scenarios and municipal regulations suggest a window of opportunity to embed ecological initiatives, including PennDOT plans to reconstruct a portion of I95 at the Girard Interchange; PWD goals to capture 100% of stormwater generated by new projects; EPA mandated CSO separation; the Estuary Restoration Act; and new waterfront development along Delaware Avenue and the Delaware River.
This draft outline offers a thematic framework as well as specific recommendations for grounding the Delaware Waterfront plan within an ecological systems approach
in four components; Analysis of existing natural and man-made systems; sustainable strategies tailored to the Upper Delaware Estuary; ecological design typologies illustrated through site specific examples along the river; directions for landscape management.
ANALYSIS Natural Systems - larger ecological systems and their implications for creating a sustainable infrastructure. These natural systems are sets of relationships that, in order to be sustainable, we must strive to understand, integrate and support. By honoring and working within the framework these relationships provide, we may derive goods and services within our 7 mile stretch of downtown Philadelphia. It is important to be mindful however, that these intricate relationships have implications that extend well beyond the imposed limits of this study. The following is a list of initial topics to consider when thinking about our unique waterfront.
Dock Creek and Drawbridge at Front Street from Watsons Annals V1
The historic streams mapped to the left were buried in sewers in the early 1900s. The above etching depicts Dock Creek (present day Dock Street) in its transition from free flowing waterbody to sewer.
Upper Estuary - Upper Zone
Lower Estuary - Transition Zone New
Bay - Lower Zone Delaware Bay
Atlantic Ocean Delaware
Submergent Aquatic Vegetation
Valisneria americana (Eelgrass) Elodea canadensis (Waterweed) Potamogeton pectinatus. (Sago Pondweed) Ceratophyllum demersum (Coontail) Potamogeton perfoliatus (Redhead Grass)
Caltha palustris (Marsh Marigold) Carex crinita (Fringed Sedge) Carex lurida (Bladder Sedge) Iris versicolor (Blue Flag) Nuphar lutea (Spatterdock) Pontederia cordata (Pickerelweed)
daily tidal inundation
Delaware Estuary • The Philadelphia Central Delaware Waterfront is part of the Upper Estuary of the Delaware River. °° This section is tidal, with free-flowing waters between Delaware Bay and river sections north of Trenton. °° The 7-mile stretch is bounded by the confluence of Darby Creek to the south and Poquessing Creek to the north. °° This section has a daily tidal flux of 6 to 8 feet on average. °° Tides combined with storm events exacerbate flooding. • The Upper Estuary is characterized by intertidal wetlands, fed by freshwater streams. • The salt line fluctuates and has generally remained below Wilmington. • The optimal shoreline from an ecological perspective is a gradual transition from subtidal areas (aquatic zone), through intertidal areas (marshes) and swamps, to uplands (floodplain forest)1 °° Submerged, aquatic communities occur at depths of 6+ feet and are typically dominated by eel grass. °° Intertidal marshes are characterized by emergent vegetation at depths of 4 to 5 feet. °° Wet Meadow-Shrub Swamp communities occur within the frequentlyinundated zone. °° Sycamore-river birch–cottonwood floodplain forest is characteristic of the upland zone.
Wet-Meadow Shrub Swamp
Spiraea alba (White Meadowsweet) Spiraea tomentosa (Steeplebush) Cephalanthus occidentalis (Buttonbush) Alnus serrulata (Smooth Alder) Calamagrostis canadensis (Bluejoint)
Platanus occidentalis (American Sycamore) Populus deltoides (Eastern Cottonwood) Betula nigra (River Birch) Acer negundo (Box Elder) Acer saccharinum (Silver Maple) Salix nigra (Black Willow)
Dulichium arundinaceum (Threeway Sedge)
3 4 5 6
Potential Areas for Wetland Creation FEATURES: • gradual slope of littoral shelf / depth ratios • appropriate soil characteristics • ability for wave/wake attenuation
Acres Site Location 8.3 1 Btw Lewis & Wheatsheaf 1.4 2 End of Allegheny 1 3 N of Penn Treaty Park 1.1 4 S end of Sugarhouse site 5 N end of Festival Pier / Trump Tower 2.5 1.8 6 S end of Festival Pier 33.0 7 Washington through Snyder 1.4 8 Pier 86 0.6 9 Pier 92 3.7 10 End of Packer total
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Delaware River Habitat • The Upper Delaware Estuary is an extremely complex ecosystem marked by high productivity, internationally recognized habitat, and a large range of biodiversity.2 • Daily tidal flux creates conditions for both aerobic and anaerobic communities to thrive.3 °° Breakdown and cycling of nutrients is more rapid with both conditions present. °° Additional nutrients are brought in and distributed by tidal action. • Historic Biogeomorphology - process-morphology dynamics, (or the relationships between the tide, sedimentation/deposition, base substrate, and plant and animal communities) create islands of habitat in the Delaware Estuary tidal freshwater marsh under natural conditions. • Edge conditions and depth fluctuation, coupled with orientation, create micro-habitat conditions that allow for many different species to thrive in close proximity. Philadelphia’s piers, though not designed for habitat, are better than a straight line of bulkhead along the waterfront. • The Upper Estuary is part of a larger habitat corridor and is important for different species at different times of the yearly cycle. • Atlantic flyway for migratory birds – song birds, water fowl, raptors • Anadromous fish spawning migrations • Existing “natural” areas are highly disturbed with remnant communities. °° Remnant floodplain forests at Pennypack Creek and Petty’s Island °° Bald eagle nesting site reported at Navy Yard spring 2007 • The potential for restoring/creating intertidal marshes exists when these three factors are addressed 4 1. Gradual slope of littoral shelf, and appropriate depth range 2. Appropriate sediment character 3. Wave/wakes can be attenuated
Physiography • Remnants of natural topography exist within this immediate watershed. °° Old streambeds may have hydrologic soils and exhibit drainage patterns that have implications for habitat type and stormwater function, especially in upland parcels. • Sub-watersheds have been modified and follow combined sewer drainage pattern and are known as sewersheds. °° Combined sewers (CS) are for the most part, gravity-based and follow natural/historic topography. • Parts of the waterfront lie within the 100 year floodplain. °° Significant recent floods have occurred in 2004, 2005, and 2006 – all have exceeded flood stage by over nine feet, as recorded at Philadelphia/Mt Holly monitoring station (NOAA/NWS).
Weather Patterns • Wind direction °° NW in November – March °° SW in April – October °° Strongest winds in September & December • Sun Angles °° Philadelphia latitude = 40˚00’ North °° Sun positions on solstices °° Dec. 21, 9am and 3pm: Altitude = 14˚, Azimuth = ±42˚ °° June 21, 9am and 3pm: Altitude = 49˚, Azimuth = ±80˚ • Storm Events °° Occur year round °° Snow melt contributes to flooding in early spring °° Tropical system storms have caused significant flooding in Delaware Valley, most recently in September 2004 post-Hurricane Ivan.
PHILADELPHIA WINDS N
AVERAGE WINTER WINDS
AVERAGE SUMMER WINDS
S WIND SPEED (KNOTS)
12% 14% E
Wingohocking Creek Sewer under construction, 1909 City Archives of Philadelphia
Major sewer lines
ANALYSIS Man Made Infrastructure â€“ constraints and opportunities for converting existing infrastructure into green infrastructure. Throughout our history, Philadelphia has been a hub of innovative thinking and the forerunner of instituting cutting edge ideas aimed to enhance the quality of life for its inhabitants. As we continue to build upon our collective knowledge, it is with this Philadelphian zeal we should approach the opportunity our waterfront holds. This section looks at the implications of our prior land use decisions with a critical eye toward the future. All of the areas below should be considered opportunities for innovation and improvement.
Aramingo Canal during its conversion into a sewer, April 1, 1901 PWD Historical Collection
Mill Creek Sewer under construction, 1883 PWD Historical Collection
Soil Compaction, Loss/Deposition and Pollution • The majority of soils in the study area can be classified as urban and are anthropogenic, meaning they have been altered by humans. °° Pore space within soil structure has been compressed by heavy material and equipment. This reduces ability of the soil to infiltrate water and prevents root penetration. °° Fill materials like concrete and dredge change the chemical makeup and alter the chemical interaction of soil biota. °° As a result of industrial activities, soils may also contain heavy metals and hydrocarbons, as well as other toxic substances. °° Many times top soil has been removed by construction activities and not replaced and/or allowed to erode away. • Altered soil properties result in a reduced ability to perform the critical functions or activities of natural soil. • Soil-building processes can be designed and managed for, however the timeframe for rebuilding healthy soil is not overnight.
Urban surfaces: Permeability and Albedo
• Urbanization along the waterfront will further increase the amount of impervious surface and therefore contribute to runoff into the Delaware River. °° Impervious pavements (asphalt, concrete, mortared brick, stone, etc.) seal surfaces, repel water, and prevent precipitation from infiltrating soils. °° Intense storms quickly generate large volumes of runoff. °° Impervious surfaces cause non-point water pollution problems. °° Impervious surfaces have higher thermal conductivities than do vegetated, pervious surfaces. • Urbanization also has the potential to increase the “urban heat island effect.”5 °° In urban areas, buildings and paved surfaces have gradually replaced preexisting natural landscapes. As a result, solar energy is absorbed into roads and rooftops, causing the surface temperature of urban structures to become 50 - 70 °F higher than the ambient air temperatures. °° As surfaces throughout an entire community or city become hotter, overall ambient air temperature increases. This phenomenon, known as an “urban heat island,” can raise air temperature in a city by 2 - 8 °F. • Increased albedo (solar reflectivity) of urban surfaces, vegetated surfaces, and permeable surfaces are effective ways to combat the heat-island effect.
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Drainage Districts drains SW drains SE drains NE drains to Delaware
1 inch equals 1,000 feet
Sewer Infrastructure • The majority of sewers in the study area are combined and route wastewater to a treatment facility to the south. The area from the Conrail overpass and north drains to another treatment facility. °° Aggregates of upland sewersheds contribute sum runoff and sewage to specific combined sewer outfalls (CSOs) at corresponding points along the river. °° Trunk sewers follow existing E/W street grid pattern while the main interceptor sewer runs parallel to the waterfront. °° Some historic streams have been converted to trunk sewers and cannot be daylighted within this watershed as they are now combined sewers connecting directly to outfalls. °° Discharge velocity, nutrient and pollution loads are a concern at all outfall locations. °° Effluent contribution to the Delaware is greatest in big storm events when sewers run full, discharging more than once a week on average. (yearly) °° Upstream stormwater separation and infiltration reduces the contribution of effluent from sewersheds. °° Delaware waterfront land is not able to mitigate the volumes coming from upland sources. • A sliver of riverfront area drains directly to Delaware River, some through separated storm sewer systems, others via overland flow. °° All of these small sewersheds can be studied for local infiltration and stormwater mitigation opportunities. °° A shoreline buffer could ideally mitigate water quality for a one-inch storm for the adjacent upland site.
Drainage Types by Sewershed combined sewage and storm storm only, no sewage separated overland associated outfall
1 inch equals 1,000 feet
k k k k
k k k k k k
Upland Sewersheds & Corresponding Outfalls
k k k k
1 inch equals 1,000 feet
Block Orientation 8° SOLAR SPACING: wider for maximum solar gain
30º SUMMER WIND 20-30º
WINTER SOLAR ORIENTATION
OPTIMAL GRID ORIENTATION FOR SOLAR GAIN
Streets and Building Orientation • Original North-South-East-West block orientation laid out by Penn does not take full advantage of solar orientation strategies. 54° 30°°° Due to the bend in the Delaware River, streets perpendicular to the waterfront on both the northern and southern end of the study area maintain desirable solar orientation. °° In temperate climates, those streets offset from the cardinal directions at an angle between 20-30 degrees achieve optimal orientation for solar gain, daylighting, and passive heating.
8° SOLAR SPACING: wider for maximum solar gain
30º SUMMER WIND 20-30º
WINTER SOLAR ORIENTATION
OPTIMAL GRID ORIENTATION FOR SOLAR GAIN
CENTRAL DELAWARE RIVER EDGE CONDITIONS 1. 2. 3. 4. 5. 6.
Pier on pilings Rip-rap with backfill Remnant wooden pier Concrete bulkhead Pier with concrete bulkhead and rubble fill Pier with wooden bulkhead and soil fill
Bulkhead - Seawall • Much of the Central Delaware River edge is concrete seawall, however other types of bulkhead exist. °° Different types of bulkheads in conjunction with the various types of backfill create distinctive conditions and therefore support particular types of biota. °° Bulkheads were designed, and function to this day to resist routine flooding events and erosion from wake of passing ships. °° All bulkheads in central portion will be overtopped by 100 year flood events °° The abrupt edge acts as a barrier to habitat, disrupting smooth transitions between aquatic and terrestrial systems and the exchange needed for healthy habitats. • Bulkheads should be evaluated for repair. °° Failing bulkheads may present opportunities for vegetated seawalls that work with habitat or other innovations. • Example: artificial reef, Lake Ontario, Toronto
Existing Openspace • Current openspace does not relate to the river °° Existing waterfront parks do not engage the river • Openspace within the immediate downtown is not connected, or networked • These spaces proved marginal ecosystem services, and could be utilized to a greater extent.
SUSTAINABLE STRATEGIES These are overarching ideas that integrate the waterfront and its related urban fabric, treating the mosaic of uses as complex interrelated systems. Specific design guidelines are dependent on location, orientation, and opportunity, and are illustrated in the following section. Each set of guidelines includes the issues, strategies, and anticipated benefits.
1 Nature as Infrastructure Regional Ecosystem Services and Collective Assets
2 Productive Landscapes and Multiple Scales Thinking Beyond Simple Amenities
3 Climate Regulation Block and Building Orientation for the Urban Grid
4 Plan for the Effects of Global Warming Adapting to the Changing Future
5 Alternative and Sustainable Energy Solutions 6 Adaptive Reuse of Historic Structures and Landscapes 7 Interactive Planning 8 Creating and Restoring Habitat
NATURE AS INFRASTRUCTURE Regional Ecosystem Services & Collective Assets
Issue: The Delaware Waterfront is more than a river edge. When viewed as a viable, whole entity that functions as an integrated system, the waterfront’s value is greater than the sum of its parts. The natural processes of healthy ecosystems are provided at no cost to the benefit of all Philadelphians, and can be an alternative to the hyper-engineered infrastructure that has come to dominate our cities. Ecosystem services include: flood protection, bank stabilization, water and air purification, climate regulation and moderation, carbon sequestration, food and raw material production, waste decomposition, erosion control, biodiversity, genetic resources, and wildlife habitat. Strategies: 1-A: Think Bio-logically – biomimicry lends ideas for a new infrastructure • [3.8 billion years of evolution along the Delaware has refined what works, what is appropriate and what lasts. Biomimicry is a new way of viewing and valuing nature. It introduces a new era based on not what we can extract from the natural world but what we can learn from it. It then imitates what was learned to create designs which solve human problems.]6 • Insights from the study of Delaware Estuary can be employed when developing the Delaware Waterfront • Processes can be mimicked in specific engineered solutions or harnessed as part of a larger ecosystem. • Healthy ecosystems and their services are resilient and able to adapt to change. • Timeframe and lifecycles are important considerations when planning for this type of infrastructure. • Although current land use practices can alter ecosystem services to the point where they are significantly imperiled, restoration may be possible in the long term 1-B: Economy of Ecology – the value of ecosystem services • [Because so many ecosystem services are provided by the natural world at no apparent cost, humans often under-estimate or ignore their value when making land use decisions]7
• Ecological services provided by wetlands, riparian buffers, urban forests and other BMPs utilizing natural processes can be quantified in monetary terms. °° [Valuation is critical to incorporating the importance of ecosystem services into decision making frameworks, which are largely structured in economic terms.] °° Lack of information on the role and value of biodiversity is a problem when trying to incorporate these services into a market economy. °° Ecological valuation tends to capture only a marginal part of real value – total value is priceless. • Quantify infrastructure by revealing economic savings and long-term fiscal benefits of ecological planning. °° New York City drinking water case study example: $6 Billion dollars estimated to replace Catskill Watershed services °° US Forest Service and UC Davis undertook a study of the value of street trees in New York City in annual energy savings, air quality, stormwater runoff treatment, and real estate sales. The study determined that street trees are collectively worth $122 million a year to the city, with an average of $50 to $300 apiece.8 1-C: Collective Assets: The benefit of the commons • 92 % of Philadelphians believe that environmental and infrastructure improvements are necessary to improve the area’s economic competitiveness and growth.9 • Open space as a collective asset can actually save municipal money: More than 60 fiscal impact studies indicate that preserving open space is likely to be a less expensive alternative for communities than residential development (which requires costly infrastructure and city services). 10 • Green infrastructure advertises and pays for itself over time: Increased property values, desirability of neighborhoods, and public health are subsequent gains. • Set an example for the entire Delaware Watershed. Over time, cities upstream and downstream will follow suit. What we stand to gain: When we think of nature as fundamentally no-cost infrastructure, or better yet, infrastructure that gives back, the benefits are staggering. Bio-logical and bioregional thinking allows Philadelphia to implement solutions that are tailored to this region while positioning this unique city within its larger environmental context.
PRODUCTIVE LANDSCAPES AT MULTIPLE SCALES Thinking Beyond Simple Amenities
Issue: In order to use natural processes as a significant contributor to our infrastructure, these services need to be applied at multiple scales and incorporated wherever possible. Hence, ecological planning must be a central focus and not at the fringes of the design process. Strategies: 2-A: To leap forward, look backward • Solutions for enhancing Delaware waterfront quality are found in what lies behind it: water management starts in the hundreds of micro-sheds within upland Philadelphia. Mitigating stormwater within these sheds will yield compound savings and successes at the Delaware waterfront. • Promote infiltration, evapotranspiration, and water reuse through BMPs in corresponding sewersheds. • Strategies for stormwater treatment, energy efficiency, and air quality at the waterfront should be seen as catalysts for incremental greening of upland areas, reaching back into the fabric of Philadelphia. 2-B: Flex Space: public spaces must serve multiple functions • Rethink the conventional definitions of “park” – parks can include area under freeways, abandoned piers, common back-alleys, etc. • Consider parks as areas of production, e.g., nurseries for street trees. • Envision streets as collectively owned open-space with multiple possible uses. • New streets should be designed in consideration of the overall health and effectiveness of Philadelphia’s urban forest. • Design streets with continuous tree trenches with infiltration capacity and passive aeration and watering pipes. • In general, broadleaf trees are most effective at sequestering carbon, scrubbing air-pollution, and mitigating stormwater runoff. • New parking lots should be designed with multiple objectives in mind. • Parking lot design should include vegetated swales and subsurface water storage. • Parking lots, new and old, should be designed or retrofitted to provide greater than 50% shading by tree canopy to reduce ambient surface temperatures and heat-island effect.
• Surface parking lots adjacent to waterfront should be seen as opportunities for flexible event space. • Stadium - in planning large parking lots with intermittent use, permeable “green” solutions such as pervious pavement and stabilized soils. • Vacant lots and underutilized properties can be managed as open space that supports ecological objectives. • Open space should create community with nearby neighborhoods. Consider temporary leases for community gardens, local and regional food markets, informal art and performance areas. 2-C: Connective Tissue - Contiguous Open Space engages the bigger picture • Continuous riparian buffer averaging 100’ - 300’ wide allows for rich diversity of estuary-based plant and animal communities, while also serving as valuable recreational area for people. • The variable width of the riparian park allows vital interspersion of micro and macro habitats • Connected park systems are commonly used by local residents as alternative transportation corridors 2-D: Manage Stormwater ecologically - Design strategies will honor and support the primary ecological resources provided by the river • Strengthen natural resource connections for all parks and make stormwater management visible – rainwater pools, native vegetation, connected wetland systems, etc. • Landscape areas need to manage 100% of own stormwater contribution. • Landscape at waterfront should also manage 100% of stormwater from buildings within riverfront development parcels. What we stand to gain: Nature makes the most of every square foot of earth by multi-tasking. To make the most of our valuable public spaces, it is time to rethink Philadelphia’s urban landscape as having multiple possible uses. Thinking beyond simple amenities lets us see the value in every inch of real estate, whether that value is in terms of the possible ecological services provided, or in terms of the social value of public open space. Additionally, economic savings compound when land serves multiple functions – no longer merely a sea of asphalt, a parking lot can be a rain garden, a concert venue, a nesting site, and a market all at once. It will take a shift of priorities, but many of the solutions are quite simple, and the rewards of reconnecting to the river will be incalculable.
CLIMATE REGULATION Block and Building Orientation for the Urban Grid
Issue: The organization of streets, buildings, and open spaces has a huge impact on the sustainability of the Delaware Waterfront. Previous development along the waterfront has overlooked the benefits of urban patterns that emphasize passive design techniques for the surrounding district. When incorporated at the scale of building groups, these strategies are critical to passive design as they have a major impact on reducing or magnifying the heating, cooling, and lighting loads to which individual buildings are subjected. 50% of the energy use in the USA is consumed in the operation of buildings.11 Strategies: 3-A: The ideal block orientation in temperate climates is a grid rotated 22.5˚ off the cardinal directions.12 • This orientation maximizes solar gain in winter and shading in summer. • Extension of the existing Philadelphia grid offers multiple options for grid orientation or building orientation within blocks. • Plan for wider east-west streets and elongated east-west blocks to maximize solar gain. • Install development guidelines for allowable solar envelopes of new development - guidelines ensure access to sun for buildings, streets, and open spaces. The size and shape of solar envelopes depends on the site size, orientation, latitude, and time period for desired solar access. • This has implications for energy use – heating, cooling, daylighting, etc. 3-B: Thermal comfort in open space: • For summer cooling, streets oriented 20˚-30˚ oblique to summer winds maximizes air flow through an urban area. Buildings spaced close together minimize undesirable winter winds. • Blocks and building massing can be oriented to take advantage the passive cooling of summer winds coming off the Delaware River, thus decreasing energy loads • Street grid orientation can help to mitigate the heat island effect in dense cities.
What we stand to gain: Increased efficiency of an entire district through passive design techniques has a cumulative effect far beyond the savings of individually rated â€œgreen buildings.â€? A vision for a new street grid extending to the waterfront can take advantage of these strategies at both the large scale and the small scale to bring sustainable solutions to all new construction. Once in place, the urban pattern provides the logic for advances in green development at the parcel scale.
Streets bearing east-west are likely to be particularly uncomfortable: dark and cold in winter, bright and hot in summer.
All streets laid out at an on an angle have some winter sun and summer shade, making them generally more comfortable than streets laid out on the U.S. Land Ordinance grid.
PLAN FOR THE EFFECTS OF GLOBAL WARMING
Issue: Of the surrounding area, the urban core of Philadelphia will be the most impacted by the effects of global warming. Rising water levels, increased storm intensity, and increased ambient temperatures will have unprecedented effects, but our ability to plan for these changes can be focused and specific. Strategies: 4-A: Respect the flood plain • Do not place major utilities or infrastructure within the 100 year floodplain. • Where possible, align the boulevard to avoid the floodplain. • Re-establish flood plain vegetation wherever possible. 4-B: Approach systems thinking at multiple levels • Small but cumulative strategies can be applied across a large scale. • Strategies at the parcel scale help developers to reduce risk. • Strategies at the city scale should be developed for emergency contingencies. 4-C: Causes and effects of global warming are intimately linked – • Improvements in carbon sequestration can help temper storm events, tidal fluctuation, etc. • Improvements in air and water quality have beneficial effects on the urban forest, which has reciprocal effects on air and water. 4-D: Retrofit old buildings and infrastructure • Retrofitting and upgrading old buildings with new energy systems reduces carbon emissions and is cost-effective through energy tax credits and longterm savings 4-E: Invest in biodiversity • Healthy genetic populations (reproduced sexually) in local communities are suited to local conditions are have the ability to adapt to change and outside stressors (disease, insects…) more readily than monocultures.
What we stand to gain: Increased awareness of the negative effects of global warming is inspiring change at the level of cities, institutions, and individuals. Combined efforts from the City of Philadelphia, local businesses, and the citizenry helps protect our existing assets and plan for future growth.
500 year floodplain 100 year floodplain Delaware River
ALTERNATIVE AND SUSTAINABLE ENERGY SOLUTIONS
Issue: Sustainable energy solutions are in high demand as we face high energy prices, dependence on hydrocarbons, and increased pollution. Deregulation of electricity in 2010 is predicted to make Philadelphia’s rates among the highest in the nation. The technologies to implement sustainable energy solutions exist today, and are becoming more sophisticated each year. The Delaware Waterfront offers Philadelphia an opportunity to prove that these solutions make ecological and financial sense over the long term. Strategies: 5-A: Smart Energy Networks and Leapfrogging • Decentralized power generation reduces the need for hierarchical substations, reduces point source vulnerabilities and allows alternative energy generation to be sold back to the grid. • Information technology is integrated into the grid which allows for demand response and system reconfiguring automation – networked system allows for real-time monitoring of consumption and pricing. Smart appliances are able to respond to grid signals and power down during peak demand or higher prices, thus averting strain on the system. • Goal = The creation of profitable, demand-driven renewable electricity markets. • example: Grid Wise Project – Yakima Washington, Gresham Oregon • example: Cambodian Renewable Energy Action Plan
5-B: Alternative energy sources – geothermal, tide, wind, solar – for new and existing industrial and mixed-use development. • Smaller scale power generation strategies should be scalable. • Create incentives for alternative energy production. • Create incentives for commissioning of new construction to monitor/fine-tune the effectiveness of green technology once it has been installed. 5-C: Life-Cycle Assessment for all new construction13 • Encourage the use of low embodied-energy materials. • Encourage the use of locally manufactured materials to reduce wasted energy in transport. • Encourage the use of durable materials that are recycled and/or recyclable.
What we stand to gain: New waterfront development is perfectly situated to make use of the Delaware River as an endless source of viable energy. Scalable energy solutions can provide power to individual developments while supporting broad districts. This allows for incremental implementation of development. Risk from point source vulnerabilities overloading is reduced by decentralization and demand response, making the system more secure and reliable. Hand in hand with strategies for energy efficiency, conservation, and passive methods, new technologies will create jobs, investment, and renewed interest in renewable resources.
ADAPTIVE REUSE OF HISTORIC STRUCTURES AND LANDSCAPES
Issue: Historic structures and vacant lots abound on the Delaware Waterfront. In many cases, people do not know about the historic landscape of the waterfront because access is so limited. In addition, many structures have been abandoned and/or vacant for years, and need rehabilitation or renovation before the public is allowed access. Strategies: 6-A: Identify existing structures with potential for adaptive reuse. • Incinerator • Pulaski Park • ConRail Piers • Sunken ships at Pier 70 • Vacant piers near Walmart 6-B: Community-building - Historic structures, with or without historic designation, can be potent tools for community-building. • Examples– McMenamins, Portland OR; Artists and Cities Pittsburg PA; Artspace, Minneapolis MN
6-C: Tax Incentives - Make use of significant local, state, and federal tax incentives for adaptive reuse projects. • Federal Historic Rehabilitation Tax Credit offers 10-20% direct tax reduction credit of eligible costs for income-producing buildings rehabilitated under standards set by the Secretary of the Interior. 14 6-D: Temporary art exhibits - Events can bring awareness to historic structures and inspire “Friends Of” groups to organize capital campaigns for renovation. What we stand to gain: The viability and profitability of adaptive reuse has been demonstrated throughout the country. The unique context of the Delaware Waterfront offers the chance to reconnect to the past by way of the future. The larger landscape narrative of the Delaware relies upon the protection of significant historic structures.
INTERACTIVE PLANNING Education – Public Awareness Campaigns – Competitions – Programming
Issue: What is the next level of interactive planning? As plans for the future of the Delaware Waterfront progress, the planning process must continue to engage multi-disciplinary teams and public bodies, but there are always opportunities to advance the tools and methods of interaction. Changing demographics and social dynamics demand that the process not stagnate in outdated modes. In addition, large renewal campaigns have a history of demolishing neighborhoods with little regard to the merits of its existing fabric. In order to avoid the mistakes of the past, future planning must reach out in ways we have not yet witnessed. Strategies: 7-A: Interactive Planning Process - As development on the waterfront continues, encourage planning participation at multiple levels via interactive gaming tools that communities can access via the internet. • Example: San Franciso’s Let’s Green This City: www.letsgreenthiscity.com • Clearinghouse for green initiatives, how-to’s, classes, and calendar of public events • Multilingual campaigns with specific strategies for different community needs 7-B: Programming • Riverfront development corporations can team up with state and city agencies, local schools, and prominent businesses to bring awareness, activity, and programming to the waterfront. 7-C: Signage • Signage at the waterfront should reveal the larger picture even as the waterfront is developed incrementally. • example: Rosie the Riveter National Historical Park, Richmond, California. 15 7-D: Catalyst projects • Catalyst projects can jumpstart change but only if they are publicized, documented, and replicable.
7-E: Design Competitions • Promote design competitions for exemplar buildings, parks, and technologies. • Focus on the immense resource of Philadelphia’s colleges and universities as think-tanks for problem-solving. • example: The Green Initiative Fund at University of California, Berkeley 16 7-F: Education • Secure foundation grants for Eco-experience programming on the Delaware • Implement training programs for local educators. • Tie to regional, national and international ecological river programs. • example: GREEN- Global Rivers Environmental Education Network www.earthforce.org/section/programs/green • example: Carnegie Science Center, Ohio River, Pittsburgh
What we stand to gain: Involvement of a community in the planning process is vital and revealing. New methods for local involvement may reveal long-held truths that have not been accessible by prior methods and thus guide the planning process to new successes in Philadelphia’s unique neighborhoods. At the other end of the scale, we now have access to global knowledge and talents. Local, national, and international design competitions generate profound ideas and also bring publicity to Philadelphia’s goals for the Delaware Waterfront.
CREATING & RESTORING HABITAT
Issue: It has been estimated that 95% of the once contiguous freshwater tidal wetlands on the Pennsylvania side of the Delaware has been destroyed (Kreeger 2005).17 The decline of this habitat has had deleterious effects on the numbers and health of wildlife populations and has severely reduced the land’s ability to perform the critical functions of a healthy ecosystem. Strategies: 8-A: Go Native • Native vegetation supports the requirements of local biota community populations • Use local genetic stock – Plants that have reproduced sexually (by seed) in the surrounding areas are adapted to the conditions unique to this environment, requiring less maintenance. • A strong gene pool is the basis of bio-diversity and enables adaptation to change. 8-B: Protect from wake • Wake from passing ships create swells which are detrimental to habitat establishment • Wave attenuation structures prevent destruction of sensitive habitat by wake. • Revetments or submerged reefs should be sigmoidal in shape and placed in numerous positions to dissipate force coming from many directions. These designs should be multi-functional and support more than one purpose. 8-C: Allow for normal tidal action • Obstruction of normal tidal exchange fragments habitat. • Daily change in water level creates aerobic – anaerobic conditions that are vital to survival of the species who live in intertidal wetlands as well as associated communities (upland marsh etc.) • The flushing action that occurs with tidal waters brings in essential nutrients. • An unobstructed, gradual slope of the littoral shelf allows for daily inundation and desiccation cycles as well as periodic flooding important for palustrine systems upland.
8-D: Increase edge conditions: ecotones and smooth transitions • Ecotones, or transition areas between adjacent ecosystems, allow communities to exploit the resources from more than one set of habitats. • This contributes to species diversity, more edge conditions, more opportunities for varied habitat. • Gradual slope from submerged to upland areas allow for ecotones that have evolved relationships overtime. • Bulkheads can be modified/retrofited to work with habitat models. 8-E: Micro + Macro habitats within a contiguous corridor • Maintain corridor contiguity. Even a narrow width of trees offers some habitat benefit. • Different species have different requirements; integrating edge conditions and gradual depth fluctuation creates micro-habitat conditions that allow for many different species to thrive in close proximity. • Larger habitat “islands” support ecotones by providing a stable “home base.” 8-F: Design for top predator species • Upper level trophic or predator species like the osprey (Pandion haliaetus) and the striped bass (Morone saxatilis) have large habitat requirements that include smaller, more specific habitat requirements for their prey. Planning for these species will incorporate a range of animals and vegetation that support them. 8-G: Let sleeping pollutants lie • Releasing pollutants that have been locked in situ within the soil column into the water has negative effects on surrounding life • Use plantings and the bacterial relationships associated with their root structures to break down pollutant compounds overtime What we stand to gain: Urban habitat restoration is more viable along the Delaware River than anywhere in the city because of the tidal processes and links to the estuary. Urban biodiversity reconnects city people with nature and a fundamental part our being. Biodiverse ecosystems are more resilient, adaptive, and better able to provide ecosystem services.
Girard/Aramingo Interchange Festival Pier Pennâ€™s Landing Walmart/Pier 70
SITE-SPECIFIC EXAMPLES Each of the following sites represents an opportunity to employ general ecological strategies in a specific context. The suggestions for each site reference the broad strategies (listed in parentheses) and are coupled with analysis drawings and landscape prototype sketches. As the specifics of the site change, so too should the strategies be flexible to respond to the needs of a district, a neighborhood, a block, or a parcel.
MULTI-USE TRAIL CONNECTIONS TO EXISTING CITY FABRIC
INCREASED DENSITY ABOVE FLOODPLAIN
RAIN GARDEN GATEWAY BENEATH I-95 INTERCHANGE
100 YEAR FLOODPLAIN
Girard/Aramingo Interchange • Capitalize on historic streambed physiography and soils for wetland buffer. (Reference Strategies: 1A , 8A-F) • Employ areas beneath I-95 interchange as infiltration basins and interactive water parks. (Reference Strategies: 2B , 2D , 7B , 7F, 8A) • Widen the buffer into the Anderson site to accommodate the mitigation area necessary to treat stormwater released from rain gardens beneath the I-95 interchange. (Reference Strategies: 1B , 2C , 4A) • Connect continuous riverfront trail to existing neighborhoods via Berks St. and Cumberland St. (Reference Strategies: 2A , 6B , 7D , 7F) • Increase allowable density above floodplain as incentive to dedicate a larger portion of the parcel to the riparian edge. (Reference Strategies: 4A) • Employ topography to direct stormwater to mitigation areas along green streets with continuous tree trenches. (Reference Strategies: 1A , 1B) • To ensure efficient energy usage, use tilted street grid as justification for rigorous solar envelope guidelines within individual parcel development. (Reference Strategies: 3A , 3B)
BAC PLAN KFILLED R TED W IP ITH W -RAP EDG E ETLAN D SPE CIES
RAIN GARDEN PLAZA
TERRA CED W
BOARDWALK RIVERFRONT TRAIL
Festival Pier • Capture, treat, and convey all stormwater from Festival Pier development through a series of rain gardens. (Reference Strategies: 1A , 2D) • Employ existing inlet as opportunity for terraced tidal wetlands. (Reference Strategies: 1A , 2B , 2D) • CSOs located on either side of site at former creeks: Pegg Run to the south and Cohocksink Creek to the north. Channelize CSO outfalls farther out into river in order to allow the creation of adjacent tidal wetlands. (Reference Strategies: 1A , 8A-F) • Where hard-edged bulkheads exist, create softer edge with back-filled riprap planted with appropriate riparian vegetation. (Reference Strategies: 1A, 8C-F) • Allow extension of riverfront trail onto Festival Pier and across waterfront boardwalks. Preserve open views to water from Spring Garden Street. (Reference Strategies: 2A)
1. Demonstration streetscape that recalls the historic streambed 2. Narrative landscape with riparian planting
CONSTRUCTED WETLANDS 1. Greywater and blackwater treatment for adjacent parcels
1. Treatment zones for stormwater runoff 2. “Green fingers” connecting to Center City 3. Creates ideal orientation for passive and active solar design within adjacent parcels
Penn’s Landing • If a continuous riparian edge is not possible in the central district, move the eco-services inland to Delaware Blvd. to create the greenest of all boulevards. (Reference Strategies: 2A, 2B) • Employ high-tech methods of renewable power generation, emissions filtration, water impoundment, and water recycling along the boulevard. Make these methods visible to inform the public of the significance of sustainability. (Reference Strategies: 5A , 5B , 7D) • Development on the I-95 cap must not be allowed to become yet another barrier to the waterfront. Extend and multiply the instances of “green wedges” on the southern portion of each parcel to allow access to the river. The subtle alteration to the parcel structure also creates the ideal solar angle for daylighting and passive heating. (Reference Strategies: 2A , 2C , 2D , 3A) • Planting on Dock Street should reflect the fact that this used to be a historic streambed. (Reference Strategies: 1A , 2C , 6A) • Topography of Penn’s Landing site encourage the creation of gravity-fed rain gardens that collect, mitigate, filter, and convey stormwater from north to south. (Reference Strategies: 1A , 2D)
MULTI-USE RIVERFRONT TRAIL
100 YEAR FLOOD LINE
Formal al with urba lee to pier n park ch aracter
DETACHED PIER HABITAT ISLANDS
Submerged reefs / revetments for wave attenuation
300’ RIPARIAN BUFFER: RESTORED MARSHLAND
THREE SUNKEN SHIPS
Walmart - Pier 70 • 300’ Riparian buffer at south end of site should reflect the full range of plant communities native to this region: submerged and emergent wetlands, wetmeadow shrub swamp, upland floodplain forest with sycamore, river-birch, cottonwood as keystone species. (Reference Strategies: 1A , 1C , 2D , 4A) • Create habitat islands from existing piers. Jump-start habitat initiation with topographic modification, soil amendment, and seeding. Connect islands with sturdy piers to allow limited human access. (Reference Strategies: 8A-G) • Connect inland with green streets that convey stormwater to mitigation areas within larger waterfront park. (Reference Strategies: 2A , 2B , 2D) • Retrofit existing piers near residential development to become fishing piers. Locally based commerce on piers should be encouraged. (Reference Strategies: 6A , 7B , 7D) • To ensure efficient energy usage, use tilted street grid as justification for rigorous solar envelope guidelines within individual parcel development. (Reference Strategies: 1B , 3A , 3B) • Multi-use trail should pass through diverse river scenarios and include educational material at regular intervals: on the water island hopping, wetlands, meadows, floodplain forest, urban edge. (Reference Strategies: 2C , 7C , 7D) • Three sunken ships near south end of site are an opportunity for public education, interpretation, and/or adaptive reuse. This is an opportunity to relate the large scale 21st Century Pier to the large scale of natural processes. (Reference Strategies: 6A , 6D)
MANAGEMENT GUIDELINES 1) Developing on the Waterfront is a privilege. • All development needs to contribute substantially to the public realm. • Mitigate public costs of building in the floodplain with wetland creation/ enhancement in same tidal zone. • Sustainability overlay district along the riverfront may mitigate some public costs by reducing impacts. • Tax credits mitigate the cost burden of sustainable construction. example: Battery Park 2) River edge management entity can be conducted as a public utility • Treat river edge as green infrastructure subject to utility charges. example: Metro Greenspaces in Portland, OR • Utilize same model as Center City District for landscape maintenance – public/private partnership. 3) Ensure that river edge management is adequately funded through multiagency initiatives. • Draw on mix of funding from federal and state agencies. • Consider funding through PADCNR, EPA, NOAA Tidal Delaware River Restoration Project. • Establish working relationship with multi-state agencies – DVRBC, DVRPA. • Coordinate with DRCC, PCPC, PWD local initiatives. 4) Train landscape managers in the art and science of working with living systems. • Rivers are dynamic and management must adapt to constant change. • Accurate field observation based on natural sciences training is as important as horticultural knowledge. • Management actions need to be evaluated through continuous feedback systems – monitoring predetermined targets such as soil biota, invertebrate populations, moisture levels.
5) Partner with science institutions to track performance and trends • Track ecological performance against benchmarks - water quality, wildlife migrations, invasive plant trends. • Investigate cost/benefit methodologies to measure economic performance. • Make findings accessible through web-based media.
“Ecological education is especially meaningful along urban rivers because so much of the original ecosystem has been erased. As active, visually rich environments, rivers can be powerful tools for science and nature education. Educating the public about the river and its natural systems will generate a sense of stewardship and a connection to the river’s history.” Principles for Ecologically Sound Riverfront Design, American Rivers p46
SUMMARY The Delaware River Waterfront represents an opportunity for Philadelphia to put into practice techniques for sustainable design at an unprecedented scale. The thinking behind the analysis and strategies for truly sustainable design rely upon the three pillars of sustainability: environmental responsibility, social responsibility, and economic responsibility. Sustainability in action requires a vision over the long term for each of these three pillars. Plans for the Delaware Waterfront have the potential to be highly ecological, highly equitable, and highly profitable, but only when the planning process looks beyond the benefits of short-term thinking that has come to drive current development. Many of the design strategies presented in this report attempt to unite all three goals, and to achieve them requires bold moves. Reclamation of a wide, continuous riparian edge for diverse habitat and recreational use is essential to any attempt at ecological planning along Philadelphiaâ€™s stretch of the Delaware River. It must also be stated that the cumulative effects of smaller design moves throughout the city contribute immensely to the success of the riparian edge. By making ecological planning central to the waterfront planning process, Philadelphia is positioning itself to harness the power of ecosystem services. Much of the challenge in the process is to reveal how much ecological design methods stand to benefit everything from habitat and open space to real estate values, neighborhood desirability, and public health.
Living Resources of the Delaware Estuary, The Delaware Estuary Program 1995
Cruz, Jason, Aquatic Biologist, PWD- interview 8-31-07
Butler, Lance, Aquatic Biologist, PWD- interview 9-12-07
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Benyus, J. 2002 Biomimicry Harper Perennial
Daily, G.1997. Natureâ€™s Services: Societal Dependence on Natural Ecosystems
Randall, David K. New York Magazine: http://nymag.com/realestate/ vu/2007/04/30323/
Crompton, J. 2000. The Impact of Parks and Open Space on Property Values and the Property Tax Base, National Recreation and Park Association
Brown, G.Z., and DeKay, Mark. 2001. Sun, Wind, and Light: Architectural Design Strategies
United States Environmental Protection Agency. 2006. Life Cycle Assessment: Principles and Practice
United States National Park Service. http://www.nps.gov/history/hps/tps/tax/ index.htm
University of California, Berkeley: The Green Initiative Fund. http://bigideas. berkeley.edu/node/34
Kreeger, D. 2005. Signature ecological traits of the Delaware Estuary: tidal freshwater wetlands.
Concepts in Delaware Estuary Science and Management, No. 05-01. Partnership for the Delaware Estuary.
ACKNOWLEDGEMENTS Many thanks to the staff at PWD’s Office of Watershed who gave their time and expertise in furthering the goal to bring sustainability back to Philadelphia’s waterfront.