Understanding Flood-Risk in New York City

MAY 2020

PIL

Understanding Flood-Risk in New York City

BY Faraz Khan, Chizobam Nwagwu, and Yashashvi Tulchiya

PARTNER New York City Mayor's Office of Sustainability and Resilience

CONTENTS ABOUT EXECUTIVE SUMMARY PROJECT OVERVIEW RESEARCH PROCESS PROTOTYPE CONCLUSION

ABOUT POLICY INNOVATION LAB Led by faculty from Carnegie Mellon University's Heinz College of Public Policy and Information Systems, the Policy Innovation Lab is a new initiative that connects students with actual policy challenges and to rapidly create solutions to those challenges. For Spring 2020, the Policy Innovation Lab investigated climate resiliency challenges with external partner agencies and organizations.

PARTNER AGENCY The Mayor’s Office of Resiliency (MOR) strives to adapt New York City to the unprecedented challenge of climate change, creating a more resilient, equitable and vibrant city for the New Yorkers of today and generations to come.

AGENCY CONTACT Peter Adams Senior Policy Advisor for Infrastructure

PAdams@resiliency.nyc.gov

CMU COLLABORATORS Faraz Khan Project Manager MS Public Policy and Management

+1 (773) 490-8220 fhk@andrew.cmu.edu

Yashashvi Tulchiya Urban Design Specialist Masters of Urban Design

+(91) 97170 07968 ytulchiy@andrew.cmu.edu

Chizobam Nwagwu Policy Specialist MS Public Policy and Management

+1 (408) 843 0032 cnwagwu@andrew.cmu.edu

Chris Goranson Distinguished Service Professor

cgoranso@andrew.cmu.edu

Smita Satiani Adjunct Instructor

ssatiani@x.team

EXECUTIVE SUMMARY The purpose of this project is to propose a digital tool to improve access to flood resiliency information for urban planning professionals. We completed this project with the assistance of our partner, Peter Adams, from the New York City Mayor’s Office of Sustainability and Resilience.

For the context of flood resiliency issues in New York City, we conducted literature reviews and interviewed architects, landscape architects, and engineers their perspectives and feedback. The final prototype is a series of connected maps on flooding, ecology, current infrastructure, and social vulnerability.

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PROJECT OVERVIEW BACKGROUND The MOR aims to present flood-risk information that is clear, scientifically accurate, and serves the needs of multiple users. Currently, the NYC Flood Hazard Mapper uses the Federal Emergency Management Agency (FEMA) maps from 2007 and 2015 to provide flood-risk information in the city.

Additionally, there are a plethora of other independent maps that provide flood-risk information for the City of New York such as FloodHelpNY, Surging Seas Risk Zone Map, and others. Given that these maps exist in a variety of places and people also often have to create their own maps, the MOR asked to help them develop a new centralized tool and/or map.

OBJECTIVE To design an ergonomic-friendly and comprehensive tool for New York City designers, specifically, Landscape Architects, Architects, and Engineers, that provides information on present and future flood risk, climate resiliency, and social vulnerability.

FLOODING IN NYC Since Hurricane Sandy hit New York City in 2012, flood risk remains an important concern for city residents and urban planning professionals.

However, the likelihood of any time of flooding occurring is subject to climate change and the resiliency of the current infrastructure. According to FEMA’s 2015 Preliminary Flood Insurance Rate Maps, NYC sea levels rose by one foot over the last 100 years and are expected to rise between 8 and 30 inches by 2050. This sea-level rise will impact thousands of residents, public spaces, and buildings. Considering the risks to already vulnerable communities, the City is eager to understand opportunities to strengthen climate resiliency city-wide.

STAKEHOLDERS Flooding risk information is accessed by different stakeholders. Individuals working within and outside of New York City government can be considered indirect stakeholders for accessing flood-risk information, but the following are our primary stakeholders for this project:

DEPARTMENT OF URBAN PLANNING

MAYOR’S OFFICE OF RESILIENCY

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DEPARTMENT OF BUILDINGS

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PROJECT OVERVIEW Project and Sprint Timelines This project was completed over seven weeks and in five sprints. The first few weeks were spent setting up meetings, followed by sprints one through four, Sprint five primarily consisted of finalizing prototypes and our Minimal Viable Product (MVP).

Sprint

Dates

Description

1

3/29 - 4/2

Setting up project management resources and conduct research

2

4/2 - 4/9

Project scoping, finalize target audience

3

4/9 - 4/16

Develop user journey maps and begin user research interviews

4

4/16 - 4/24

Synthesizing user research into a report, creation of first prototype

5

4/24 - 5/2

Prototype demo, usability testing, and development / testing of the MVP

Our Project Overview summarizes relevant links, documents, and external resources used for our sprint planning and related project documentation.

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RESEARCH PROCESS SPRINT ONE After reviewing the partner’s project overview, our team began drafting our “how might we” questions to guide us. Our initial questions included: How might we create an accessible, real-time, and predictive dashboard for the NYC Mayor Office of Resiliency to determine flood risk information?

How might we learn the different types of information that can be useful when presenting flood-risk information to multiple users?

The initial phase of our project reflects a heavy analytics project. However, after having an extensive discussion on what the MOR is aiming to focus on, we understood their approach to be more research-based and user-focused. Our team conducted background research on flood-risk policies and how NYC is one of the most vulnerable cities to climate change. A New York Times article claims that mapping flood-risk can be controversial; one the one hand, having access to flood-risk can be helpful for planning natural disasters, but on the other, having information on flood-risk can lead to higher flood insurance rates and lower property values for residents.

SPRINT TWO After discussing the needs of different users with the partner, we decided to shift to clarifying objectives, understanding more about how flood-risk is currently presented, and identifying target users. We identified the intended users of the tool and decided to focus on four different users: designers, planners, local community, and policy makers.

Given that the four different user types can be overwhelming, we decided to hone in on designers for this project. More specifically, within the designer community, we decided to focus on landscape architects, architects, and engineers. The decision to focus on designers stemmed from the team’s interest in creating a tool for users who currently do not have one. Moreover, given the broad community of designers working in New York City, this seemed like a great opportunity to consult with individuals from different backgrounds in order to create a comprehensive and robust tool.

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RESEARCH PROCESS SPRINT THREE With the targets identified and preliminary research completed, we moved onto developing user journey maps and interview guides. We developed journey maps based on our preliminary research for each type of designers. We quickly realized the gaps in information based on the steps that each designer needs to take to access flood-risk information. Additionally, given the plethora of reasons for needing flood-risk information, it became difficult to hone in on how floodrisk information can be relevant to them. We moved onto developing interview guides to speak with the designers directly. For landscape architects, we aimed to learn more about relevant ecological measures and green infrastructure. For architects, we aimed to learn more about datasets required for design decisions. For engineers, we aimed to learn more about how flood-risk is utilized in planning new buildings. Read more about our key interview findings in the “Key Findings” section.

SPRINT FOUR We secured interviews with four architects, two of them closely associated with engineers. Based on the interview findings, we designed an initial prototype. We used Balsamiq, a wireframing tool, to outline the information captured in the interviews.

SPRINT FIVE After developing initial prototype, we were able to get feedback from additional users and update them. Our final prototype can be found in the "Prototype" section.

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RESEARCH PROCESS Key Findings We conducted seven user interviews total (all architects based in NYC). All interviews were conducted via Zoom.

Most were familiar with FEMA flood maps -- all use their maps to assess flood-risk, noting having to rely on two maps for best and worst case scenarios.

All users voiced a difficulty with indiscriminate flood zone boundaries on FEMA maps -- they would prefer flood maps that acknowledge NYC building boundaries.

Majority of users noted other measures like precipitation, heat, and design flood elevation needed to improve project resiliency at local level.

There was split opinion among users on relevance and potential impact of including equity measures -however, all agreed data on social vulnerability would need to be updated periodically.

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RESEARCH PROCESS Findings: User Quotes "The basis for flood design should be tied to borough block number.

The weird thing about the FEMA maps is that it does not clearly define zones within the city."

"I think you have to consider [equity].

In light of COVID-19, it would be absolutely critical to understanding how these different resiliency measures interact."

"You don’t have to design for dryness all the time.

How does the city drain in an intense storm event or high tide? It helps to have inland flood levels and tide inundation levels to understand where their site is draining to."

"A live, up-to-date feed for communities to share flooding information would be useful for planners."

"NYC is unlike other city and FEMA does not vary their methodology, so in NYC, when you zoom in the lines are arbitrary making it difficult to judge compliance" "You should be able to to pick a number of different climate resiliency measures and see them overlaid on top of each other.

We need to be able to understand how these things overlap!"

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PROTOTYPE Searchable and Basemap Layers BUILDING UPON EXISTING FORMATS Considering the needs of our users, we recognized the need for our prototype to build on existing datasets and technology. The searchable and base layer maps are sourced from Google Maps. Our stakeholders and intended users are familiar with these maps for identifying NYC zones and boundaries. The opening page of the website will display a map of NYC. The user can search for the neighborhood and building they want information for. This provides a clear baseline for where additional layers will overlay.

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PROTOTYPE Ecology Layer

CAPTURING LOCAL BIODIVERSITY Based on interviews, we narrowed down to four main information points necessary for the Ecology layer: watershed, soil bearing capacity, habitat types, surface permeability, and tree canopy. Originally, soil was listed as our main information point. We found that soil types vary by project and are not a consistent or relevant data point for practitioners. They suggested surface permeability because it gives the designer an idea of what to expect for certain sites. Additionally, tree canopy and habitat types capture the existing biodiversity in certain parts of the city. One of our interviewees noted that they just started working on projects that required understanding the marine life in the City’s waterfront and waterways, famously dubbed the “sixth borough.”

From their recollection, there’s little data on the amphibious life in those waterways. Knowing that information ahead of time could be useful for identifying different ways to approach projects that interact with such waterways. On the topic of tree canopy: it is noted as a strong indicator of environmental health inequities. Knowing that information would also be helpful for planners to increase tree cover in areas in need of more tree cover.

That information is publicly available, but is not currently at the first-hand disposal of such practitioners.

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PROTOTYPE Infrastructure Layer

ACKNOWLEDGING LOCAL SYSTEMS Additional information like land use and old buildings can be overlapped with flood data. This would help designers in site planning and analyze the role of building in larger neighbourhood resiliency. Other information like sewer and stormwater sheds, upcoming projects and NY Solar Map were also viewed by interviewees as valid and valuable measures of resiliency that are informative for a myriad of other decision makers working in this space. These indicate metrics like energy efficiency, stormwater surge trends, and heating trends across the city.

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PROTOTYPE Flood Maps

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IMPROVING FLOOD-RISK ASSESSMENTS Currently, there are two sets of FEMA flood-risk maps, 2007 and 2015 that designers refer to. Based on our interviews, there is a need for one clear map, possibly a vector map. This allows production of high-resolution maps, with clear demarcation in areas which lie and not lie in the flood risk zones. The current NYC Flood Hazard Mapper displays point information when clicked (as in ArcGIS), but we can zoom in only to an extent, therefore boundaries of flood risk zones are unclear. We also found that there is a need to include Design Flood Elevation, the type of flooding, and clear demarcation of flood zone boundaries. Following these inputs, we incorporated the below mentioned features in the map: Layer (L) / Feature (F)

Description

FEMA Map (L)

Digital vector maps, with point information attached, accessed by clicking on a building/street in the map.

Type of Flooding (L)

A separate layer showing flooding types in different areas.

Base Flood Elevation (L/F)

L : Vector map which can be color coded to show Base Flood Elevation variations in the zone.

F: Also available as point information when you click on a map.

Design Flood Elevation (L/F)

L: Vector map which can be color coded to show Design Flood Elevation variations in the zone.

F: Also available as point information when you click on a map.

Buffer Zone (F)

Indicates outer flood hazard boundary, which can be affected due to short term environmental/urban changes.

Borough Block Number (F)

Information attached to boundaries of flood zones on map.

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PROTOTYPE Social Vulnerability

HIGHLIGHTING SOCIOECONOMIC INEQUITIES The MOR is focused on incorporating equity into flood risk information because climate change can have devastating impacts on disadvantaged communities. According to the New York City Panel on Climate Change 2019 Report, inequity in climate change adaptation stems from systemic inequalities, such as disparities in health outcomes, living conditions, and many other factors. This puts disadvantaged communities in a vulnerable position and makes it increasingly difficult for them to learn about, respond to, and recover from climate change inequities. The Hazards and Vulnerability Research Institute at the University of South Carolina provides a framework for mapping social vulnerability using the Social Vulnerability Index (SoVI), which is calculated using statistical methods and 29 socio-demographic variables, such as socioeconomic status, gender, race, age, etc. This data can be combined with existing flood-risk maps to understand where the most vulnerable populations are located. New York City does not currently have a composite SoVI developed and we recommend a prototype of what the map can potentially look like. This can be done using American Community Survey (ACS) five-year estimates data available through the U.S. Census Bureau.

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PROTOTYPE Social Vulnerability (cont.)

INTEGRATING EQUITY INTO NYC RESILIENCY When data on 29 socio-demographic variables is available, cleaned, and ready to be mapped, New York City can start analyzing it using statistical methods, such as the Principal Component Analysis used by the University of South Carolina. After the SoVI is properly implemented, the map can show where highest and lowest vulnerable populations are located.

In conversation with architects and engineers, we noticed some hesitancy in incorporating this into the final prototype. While they acknowledge the importance of SoVI, they were challenged to think about how this information can be embedded into their current work. They sounded optimistic about the possibility of having access to SoVI on top of existing flood-risk maps, but they may need more context. Additionally, we see the SoVI layer being an optional layer that can be seamlessly integrated on top of the existing flood-risk maps.

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CONCLUSION Lessons Learned CONSULT WITH SUBJECT MATTER EXPERTS EARLY During the process, we realized that our knowledge on flood risks and their impact on designing urban infrastructure was limited. The information from online sources does not concentrate on intricacies of design processes and data required for decision making. Consulting various subject matter experts (SMEs) who have first-hand experience would help in creating a better combination of datasets in the tool.

PREPARE MORE DIRECT INTERVIEW QUESTIONS In light of our inability to consult with SMEs, our interview questions came off as broad. Going forward, it is important to have a trusted SME review any interview questions to ensure the interview is productive for both the research team and the user participants.

INTERVIEW MORE STAKEHOLDERS. All four of our interviews were architects with two working closely with engineers. We would like to interview a wider category of urban planning professionals involved like landscape architects, equity consultants, more representatives from the MOR and the Department of Buildings (DOB) to understand their insights on flood risk and climate resiliency within the city.

EXPERIMENT WITH EXISTING DATA IN ARCGIS Testing the tool is equally important in the process. Working on ArcGIS would allow us to analyse problems and possibilities of relevant information that can be created with available data. ArcGIS tools would also be helpful in adding additional analysis for creating awareness on climate resiliency and equity (for e.g. Social Vulnerability Index)

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CONCLUSION Next Steps NARROWING DOWN FUTURE GOALS Acknowledging the limitations of our timeline, we believe the following steps should be taken. If we were given more time, we would have definitely explored these areas to create a stronger version of our prototype.

Action Needed

Suggestions

Identify additional data sources

For SoVI, obtain the raw data or ArcGIS files used in the study Identifying flood types in different areas to design Build in WRI ecology maps

Identify additional data sources

Decide on reorganization of layers

Identify additional data sources

More landscape architects and engineers needed to validate insights. Urban architects and additional representatives from MOR and DOB would be helpful.

Identify additional data sources

Equity was not inquired about during our initial interviews.

Expand on questions about social vulnerability and how data on inequality can be used to improve decision-making processes.

CRAFTING CLEARER PICTURE OF RESILIENCY In the long run, we learned more about the need for a tool that better captures general climate resiliency trends across the city than just a tool for assessing flood-risk. It was clear from our interviews that different climate resiliency datum relevant for building projects existed in-silos. It is important that the responsible team carries on the pursuit to identify additional opportunities to develop this project into a tool that allows designers in NYC to have a clearer picture of what resiliency measures need to be taken into consideration based on their project.

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REFERENCES Bliss, Laura, and Laura Bliss. “FEMA's Flood Risk Maps Have a Dangerous Flaw.”

CityLab, August 25, 2017. https://www.citylab.com/equity/2016/09/fema-floodrisk-mapping-flawed/498242/.

Carolyn Kousky Feed Carolyn Kousky, Wharton Risk Management and Decision Processes Center, and University of Pennsylvania. “Why Americans Are in the Dark About Flood Risks.” CityLab, October 11, 2018. https://www.citylab.com/environment/2018/10/how-america-failscommunicating-flood-risks/572620/.

Chen, David W. “In New York, Drawing Flood Maps Is a 'Game of Inches'.” The New York Times. The New York Times, January 8, 2018. https://www.nytimes.com/2018/01/07/nyregion/new-york-city-flood-mapsfema.html.

“Find Your Flood Zone in NYC.” Find your flood zone in NYC | FloodHelpNY.org.

Accessed May 3, 2020. https://www.floodhelpny.org/.

Foster, Sheila, Robin Leichenko, Khai Hoan Nguyen, Reginald Blake, Howard Kunreuther, Malgosia Madajewicz, Elisaveta P. Petkova, et al. “NYAS Publications.” The New York Academy of Sciences. John Wiley & Sons, Ltd, March 15, 2019. https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/nyas.14009.Flood Risk in NYC Information Brief - New York City. (n.d.). Retrieved May 3, 2020, from https://www1.nyc.gov/assets/planning/download/pdf/plans-studies/climateresiliency/flood-risk-nyc-info-brief.pdf “ Hazards & Vulnerability Research Institute.” Hazards & Vulnerability Research Institute | University of South Carolina. University of South Carolina. Accessed May 3, 2020. http://artsandsciences.sc.edu/geog/hvri/front-page.“National Flood Insurance Program Policy Index.”

National Flood Insurance Program Policy Index | FEMA.gov. Accessed May 3, 2020. https://www.fema.gov/national-flood-insurance-program-policy-index.

“NYC Flood Hazard Mapper .” Header Controller NYC Flood Hazard Mapper. NYC Department of City Planning, November 6, 2017. https://www.arcgis.com/apps/webappviewer/index.html? id=1c37d271fba14163bbb520517153d6d5.

NYC Department of City Planning. (2016, November). Intro Brief: Flood Risk in NYC. Retrieved May 03, 2020, from https://www1.nyc.gov/assets/planning/download/pdf/plans-studies/climateresiliency/flood-risk-nyc-info-brief.pdf “NYC 's Risk Landscape: A Guide to Hazard Mitigation.” NYC :The Official Website of the City of New York, n.d. https://www1.nyc.gov/.“

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REFERENCES(CONT.) “Surging Seas: Risk Zone Map.” Climate Central. Surging Seas: Risk Zone Map. Accessed May 3, 2020. https://ss2.climatecentral.org/#13/40.7368/-73.9935? show=satellite&projections=0-K14_RCP85-SLR&level=10&unit=feet&pois=hide.

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