Lower Manhattan Class Project Manhattan is arguably New York City’s most famous borough, hosting some of the world’s most iconic sites, such as the Empire State Building, Times Square, and the theaters of Broadway. With an estimated population of 1.63 million in just 23 square miles, Manhattan is the most densely populated of NYC’s five boroughs and is the most densely populated area in the United States. NYC’s total human population is approximately 8.5 million and continues to grow annually, which poses a threat to the city’s biodiversity. Additional threats include pollution, climate change, sea level rise, stormwater management, and new development. The city has made progress towards the promotion of greater biodiversity and climate adaptation through several ongoing initiatives and programs. Two major initiatives include PlaNYC, the environmental and economic sustainability plan for NYC that was released in 2007, and the NYC Green Infrastructure Plan, which was released in response to Hurricane Sandy. The New York City Department of City Planning (DCP) also recently amended the city’s zoning code based on recommendations from an initiative called Zone Green to remove impediments to the construction and retrofitting of green buildings, empowering property owners to upgrade sustainably. Additionally, the NYC Nature Goals 2050 established naturerelated goals for the city to strive for.
Our class project focuses on Lower Manhattan, particularly between Water Street and Wall Street, to explore ways in which the area can promote and enhance biodiversity, in terms of both plant species and wildlife, as well as mitigate climaterelated issues. Water Street is one of Lower Manhattan’s most important commercial corridors, running more than half a mile from Whitehall Street to Fulton Street. This predominantly commercial corridor hosts a variety of large companies but lacks the vitality of NYC in human activity, programming, and nature. The Alliance for Downtown New York created a Vision Plan for Water Street in response to these concerns, among many others. Similarly, Wall Street, an eight-block-long corridor in NYC, is one of the leading financial centers of the world and has become notorious over time as a metonym for the overall financial markets of the United States. Like Water Street, Wall Street lacks biodiversity at the street level and would benefit greatly from public realm improvements. Through investment in natural areas, the addition of green infrastructure, and the renewal of biodiversity, our class believes that Lower Manhattan can capitalize on an extraordinary natural and social ecology. This chapter provides an overview of existing environmental conditions in NYC and initiatives that seek to improve them.
Current and Projected Environmental Conditions in NYC Summary A variety of changes to the climate pose serious threats to human health and safety, biodiversity, and the built environment. The current and projected environmental conditions in NYC informed our recommendations and proposals for ecological interventions in Lower Manhattan. For our projects, we particularly evaluated the impact of climate change, potential flooding from extreme weather events and stormwater management, air quality, and the impact of invasive species on biodiversity. This section contains an overview of these topics.
Climate Change
NYC is one of the greenest cities in the United States due to the relatively small ecological footprint of residents resulting from the high use of transit and occupancy of multifamily housing. However, the City conducted a study to predict a likely 2050 climate scenario and found that there will be an estimated increase in average temperature by 1.7 to 2.8°C, contributing to a worsened urban heat island effect. Precipitation is estimated to increase by 10% and the average sea level estimated to rise by 17 to 30 cm. By 2050, NYC is predicted to be hotter, wetter, have higher average sea level, and experience more frequent and intense coastal flooding and more frequent and intense heat waves.
“By 2050, there will be over 9 billion people on this planet competing with wildlife (and each other) for space and resources, and 70% percent of these people will live in cities.” United Nations World Population Prospects 2017 Revision
Stormwater Management Climate change will bring more frequent and intense storms, like Hurricane Sandy, which has prompted the city to heavily consider the impact of stormwater runoff on water quality and urban flooding. Through improved green infrastructure and stormwater management, the city can potentially avoid the public health and environmental impact of combined sewer overflows (CSOs) that result when stormwater overwhelms water and sewage systems. This issue of flooding is worsened by the fact that 72% of NYC’s land area is covered by impervious surfaces, which prevent proper drainage during floodrelated events.
Air Quality
Biodiversity and Invasive Species
NYC contains the most parkland of any United States city and approximately 21% of the city is covered by tree canopy (Figure 1). Regardless, the air quality has worsened over time due to the increase in fine particles from vehicle emissions. These fine particles account for almost 50% of the city’s air pollution. Fine particles are unseen but are responsible for countless medical issues, such as asthma and heart disease. The NYC Health Department estimates that reducing these fine particles by 10% could significantly reduce deaths and hospitalizations. Additional street plantings, trees, and other open spaces can significantly improve air quality for the benefit of human and wildlife. Million Trees NYC is one of the major initiatives in NYC aimed at combating poor air quality and enhancing biodiversity. Local organizations across NYC have been working towards increasing the tree canopy in NYC from 21% to 30%. Since 2007, the city has planted over 600,000 trees.
According to the NYC Department of Parks and Recreation, there are 26 distinct ecological habitat types, 1,450 plant species native to the five counties of NYC, 826 native plants that still have extant populations, 140 rare plant species, and 230 native species of bees. In terms of human diversity, NYC is an incredibly diverse city that welcomes immigrants and visitors from around the world. The city is projected to grow by more than 500,000 people over the next 15 years, which suggests that new development will be necessary to accommodate this growth and existing green spaces and biodiversity could be jeopardized.
Figure 1: Open space parcels in New York City, derived from New York City Landcover 2010.
The influx of people to NYC also functions as a major pathway for the introduction of invasive species. Invasive species can reduce biodiversity because they often have high reproductive rates and tend to invade the native remnants and dominate an ecosystem. After habitat destruction from anthropogenic activity, invasive species are the biggest threat to local flora. Additional threats include environmental factors, such as climate change, habitat fragmentation, pollution, and reduced pollinator availability. There are currently 140 formally designated “rare” species in NYC. High biodiversity is a good indication of nature’s overall fitness and success and allowing invasive species to overtake native species would be detrimental to the ecological health of Lower Manhattan.
NYC Plans and Programs for Climate Change and Biodiversity Summary
PlaNYC 2030 Goals:
While there are many different initiatives underway in NYC to increase biodiversity and address climate issues, PlaNYC, the Green Infrastructure Plan, Zone Green, and Nature Goals 2050 are four of the leading initiatives, programs, and plans.
1. Create homes for almost a million more
PlaNYC 2030 PlaNYC is an economic and sustainability plan for NYC. It was released in 2007 to prepare NYC for the anticipated population growth, strengthen the economy, mitigate the impacts of climate change, and enhance overall quality of life for residents of the city. The plan primarily targets: housing, parks and open space, brownfields, waterways, water supply, transportation, energy, air quality, solid waste, and climate change. To address these targets, the plan established a series of goals, which are listed to the right. PlaNYC resulted in the creation of 127 initiatives, such as the MillionTrees NYC Initiative. The plan was updated in 2011, adding 5 new initiatives in the process. The plan has been successful to date given the focus on measurable accomplishments and frequent performance reporting.
New Yorkers while making housing more affordable and sustainable
2. Ensure that all New Yorkers live within a 10-minute walk to a park
3. Clean up all contaminated land in NYC 4. Improve quality of waterways to increase opportunities for recreation and restore coastal ecosystems
5. Ensure high quality and reliability of the water supply system
6. Expand sustainable transportation choices and ensure the reliability and high quality of the transportation network
7. Reduce energy consumption and make the energy systems cleaner and more reliable
8. Achieve the cleanest air quality of any big United States city
9. Divert 75% of the solid waste from landfills 10. Reduce greenhouse gas emissions by more than 30%
Green Infrastructure Plan The Green Infrastructure Plan was adopted in 2010 to spur the investment in resilient infrastructure, such as the use of blue roofs, larger street tree pits, green streets, bioswales, street trees, green roofs, porous concrete, and vacant lots to improve the management of stormwater runoff. The plan has committed a total of $2.4 billion over 20 years and aims to reduce the environmental, economic, and social impact of flood related events, such as sea level rise, extreme weather events, and natural disasters like Hurricane Sandy. Since 2010, the Green Infrastructure Plan has completed green infrastructure projects across NYC’s five boroughs, launched the BioswaleCare Program to support community stewardship of green infrastructure, advanced and diversified the standard designs for right-of-way green infrastructure. It also completed retrofits on over 200 streets, sidewalks, and public and private property, reduced combined sewer overflows, evaluated green infrastructure opportunities at the watershed scale, conducted planning to expand the existing grant program into a larger private incentive program, and more. The Green Infrastructure Plan builds upon and extends the commitments made in PlaNYC and the Sustainable Stormwater Management Plan, providing a detailed framework and implementation strategy to meet the city’s goals.
The NYC Green Infrastructure Program has installed thousands of bioswales, rain gardens, and permeable pavements across the city to combat flooding. Source: NYC DEP.
Bioswales collect stormwater during periods of heavy rainfall to reduce the amount of water that pools along streets. Source: NYC DEP.
The bioswales are not only beneficial for managing stormwater, but also provide a habitat for a myriad of species as well as aesthetic improvements to the streets. Source: NYC DEP.
NYC Plans and Programs for Climate Change and Biodiversity Zone Green Zone Green consists of a package of zoning amendments, city legislations, and state laws that affect all categories of buildings throughout NYC, from single-family homes to high-density commercial and office buildings. In 2013, the New York City Department of City Planning (DCP) amended the zoning code according to Zone Green’s recommendations to remove impediments to the construction and retrofitting of green buildings. The goal of Zone Green is to reduce the city’s carbon emissions by 30% by 2030 to help reduce the impact of climate change by providing owners and developers a myriad of choices for investments to save energy and money and to improve environmental performance. The retrofits improve energy efficiency, manage stormwater, and contribute to the enhancement of the city’s ecology. The amendments included allowing: solar panels on roofs despite height limits, stormwater management and mechanical systems on roofs, the exclusion of thicker, energy efficient walls from floor area restrictions, and rooftop farming. Zone Green builds on the recommendations made by the Green Codes Task Force and will help New Yorkers save energy and money from their buildings, generate clean and renewable energy, manage stormwater, reduce the urban heat island effect, grow fresh, local food, reduce carbon emissions, and promote a healthier, greener city.
Zone Green permits solar panels on NYC roofs to promote renewable energy. Source: Crain’s New York Business
Zone Green also lifted many of the restrictions on rooftop gardens. Source: Matthew Williams.
Zone Green has promoted large-scale urban farming and agriculture on roofs. Source: Heather Shimmin.
NYC Nature Goals 2050 NYC Nature Goals 2050 began in 2016 by the Natural Areas Conservancy, whose mission is to restore and conserve the blue and green spaces of New York City to enhance the lives of all New Yorkers. The NAC works closely with the NYC Parks Department to advance the care and renewal of natural areas. Nature Goals 2050 seeks to express clear goals towards long-term environmental and biological sustainability given the threats of climate change, population growth, and high-density urban life. The five key goals of the plan are: 1) promote biodiversity and ecological habitats by providing living environments for a diversity of native species; 2) improve air and water quality by supporting nature’s ability to absorb and filter water from runoff and help clean the air; 3) protect the city’s coast by enhancing nature’s capacity to mitigate damage from coastal storms; 4) improve connectivity by better enabling movements of plants and animals through the city and region; and 5) inspire others by encouraging human creativity and appreciation of nature. The goals were created through a series of three workshops and conversations between representatives of the NAC, local government, social and environmental non-profits, academics, land managers, local community members, and more. The next phase is to establish measurable and implementable goals through public stewardship, community advocacy, and interdisciplinary collaboration.
NEW YORK CITY
Nature Goals 2050