A New OASIS for New York

This post is part of an ongoing series that invites critical reflection on data visualization and urban cartography – past, present and future. To see all entries on this topic, click here. In particular, check out an in-depth conversation with social scientists – and stewardship mapping innovators – at the Forest Service that we aired way back in March.

Before Google Maps inspired a world of neogeographers, the USDA Forest Service saw the value in creating a map mashup of open space resources in New York City.  With an online interactive map, local open space advocates could visualize the concentration – or absence – of parks, community gardens, wetlands, and other green infrastructure in every city neighborhood and at a citywide scale.

To realize that vision, in late 2000 the Forest Service convened almost 40 greening groups, educators, individuals, businesses, nonprofits, and public agencies to guide a new initiative: the Open Accessible Space Information System (OASIS).  The committee selected a nonprofit mapping project to develop the interactive maps, and in March 2001 the OASIS website at www.oasisnyc.net was launched.  (The list of participating organizations has since grown to more than 60 groups).



OASIS quickly became a valuable and widely used online tool. City agencies rely on it, design firms use it regularly, and community groups and schools describe it as invaluable.  It receives tens of thousands of visits each year from people who use it to make more than one million maps annually.  Its scope has broadened to include not only mapped information about parks and gardens, but also transit routes, buildings, detailed property data and land use patterns, housing, schools and more, in order to help visualize the nexus between community greening and broader urban planning issues.  In 2005, William Neuman referred to it in The New York Times it as a “great source of information about the built environment in New York City.”


“It has become a platform for understanding how the built environment shapes – and is shaped by – the city’s natural areas and habitats.”

OASIS fills a niche. Though it was launched and supported in its early years by the Forest Service, it is neither a public agency project nor a for-profit venture nor its own nonprofit.  Instead, it sits in-between.  For example, it provides access to parcel-by-parcel data and mapped land use patterns across the five boroughs.  But unlike for-profit real estate mapping sites, OASIS provides free access to this data, helping to level the playing field for groups and individuals trying to make sense of development changes across the city. It’s the people’s mapping site for property data and maps.  By “people” we mean everyone from urban planning students, community gardeners, real property professionals, urban design firms and architects, city agency staff, teachers, neighborhood groups and community boards, the media, and more, based on user surveys and web usage reports.

And unlike New York’s Citymap application or other agency websites, OASIS brings together mapped information from many sources – not only from city agencies, but from state and federal government, private sources, and local community groups.  It therefore provides a multi-faceted and more realistic picture of what’s actually happening “on the ground” in ways that no single government entity would provide.  For example, a property that’s home to a thriving community garden might be considered vacant by the city’s real property tax assessors.  Though both views are valid, the city’s websites would only present the “vacant” information.  OASIS captures and displays both.

Also, OASIS’s purpose transcends individual agencies and organizations.  Although the project began with a focus on open space resources (and still includes a great deal of open space data), it has become a platform for understanding how the built environment shapes – and is shaped by – the city’s natural areas and habitats.  It visualizes the complexity of spatial relationships between the local, citywide, and regional scales of the city’s civic infrastructure.  And with the recent integration of demographic data from the 2000 Census and the Forest Service’s research on local environmental stewards, overlays now exist that display elements of the city’s social terrain as it relates to the environment and urban infrastructure.

But even though the site is valuable and well-used, its mapping and web technology had become outmoded, eclipsed by Google and others.  (In an online survey in 2006, many users rated the OASIS website as “good to excellent”, but a typical complaint was that the site was too slow, and people often requested more data and more up-to-date data.)  To keep OASIS relevant, this year the CUNY Mapping Service at the Center for Urban Research completely revamped and upgraded the website, integrating new mapping and website technology, adding more and newer data sets, and designing the site to allow for more interactivity.  Here’s a sampling of what you can find and do at “OASIS 2.0”:


OASIS - Atlantic Yards

Zoom to the area of the proposed Atlantic Yards site (or any other proposed development project) and view the existing buildings, community gardens, playgrounds, and institutions that would be impacted. Click from property to property to identify ownership, zoning, FAR (Floor Area Ratio), and more. Clicking the “camera icon” for each property will display a bird’s eye photo. (At the Atlantic Yards site, you can see recent housing built across the street.) Zoom out to see the larger area in Brooklyn and add layers of population characteristics.

OASIS Location Report


When you click on a property or search for an address or tax lot, OASIS’s “Location Report” offers details about the spot you clicked. For individual properties, this includes land use, ownership, and other data from the city’s land use files maintained by the City Planning Department. It also provides property-specific links to the city’s Department of Buildings website, Department of Finance tax assessment profile, ACRIS (Automated City Register Information System), and the city’s new “digital tax map” website that provides precise lot measurements and a history of lot changes. Location reports also integrate Yahoo! local search results, so any commercial activity at the lot that Yahoo has info about will appear. Community Boards and legislative districts are identified, as is relevant information about a park, school, or stewardship turf (see below) that your selection might fall on.



Ever wonder where rainwater goes when it washes off city streets?  It pours into a “combined sewer overflow” (CSO) system and then empties out of more than 400 CSO pipes (sometimes mixed with raw sewage) into the nearest river or bay.  These outfall pipes are mapped on OASIS, and you can click on each one to see a bird’s eye view of it (images at right).  Are they near local parks, beaches, or fishing spots?  Are the outfalls filtered to prevent “floatables” (pieces of trash) from emptying into the waterway?


Once you zoom in to the CSO of interest (or any other spot on the map), the new version of OASIS provides a “print” link, enabling you to annotate your map, print it with a custom title, and/or save the map image itself as a PNG graphic. Or you can include a link to each map in your blog, on Twitter, or via email. Community gardening groups such as GreenThumb and Green Guerillas already use this so their website visitors can zoom directly to community garden maps on OASIS.


OASIS - Stewardship Mapping

New York City is home to several thousand local environmental organizations, some focused on a specific block or community garden, others involved with regional parks or habitats, others advocating for citywide greening policies. Through a partnership with the USDA Forest Service’s “Stewardship Mapping and Assessment Project” (STEW-MAP), you can visualize the spatial relationships and overlapping turfs of these organizations. OASIS has a dedicated search page for the STEW-MAP groups, so you can zoom in on specific turfs, search for stewards by type and area of interest, and view citywide maps of overlapping turfs for each type of steward.

OASIS - Stewardship Mapping

When you click on a group’s name in the list, you’ll go directly to its turf on the OASIS map. You can see if any other turfs overlap with this one, who’s involved in stewardship nearby, and what natural habitats are in the vicinity.


OASIS - Mannahatta

This year marks the 400th anniversary of Henry Hudson’s exploration of his eponymous river.  To help New Yorkers understand our city’s ecological foundations, the Wildlife Conservation Society created The Mannahatta Project to map the ecosystems, soil types, shoreline, waterways, and native American trails in Manhattan circa 1609. WCS partnered with OASIS so this data could be overlain with maps of Manhattan’s contemporary environment as a teachable moment. After 400 years of dramatic changes, how will we manage our urban ecosystem for the future?


The integration of historical aerial photos provides a compelling visual narrative about local development. Here’s an example: on Staten Island, the Kreischer Hill Woods covers 130 acres of rare plant species and important ecological communities.  In 1996, the area was still pristine (see above). By overlaying tax block and lot boundaries on the image and using OASIS’s aerial timeline slider, we can see that by 2004, some type of property improvement had taken place.  By 2006, the aerial images show that a shopping center with Home Depot, Target, and other stores had been built and parking lots had paved over a former pristine environment.

• • •

The Open Accessible Space Information System in New York – as concept, collaborative partnership, and mapping website – will soon be 10 years old.  It has survived and thrived so far for several key reasons.  Its mission is still valid – a common, free, open space inventory via a web-based GIS mapping resource is invaluable to the city’s greening and planning communities.  Its structure is flexible enough to evolve by accommodating new groups and interests, integrating new data sets, and seeking new and varied funding sources.  And the partnership groups and website managers share an interest in harnessing new online tools in practical ways for a wide array of users.

The new version of OASIS emphasizes ease of use, interactivity, and user input. The relationships that provide user input are diverse and are brokered by the project team. For example, The Academy for Urban Planning in Bushwick is hoping to photograph every CSO in the city, map all of them, and learn more about their impacts.  The Academy can integrate these photos (posted on Flickr) into OASIS’s maps and use the site to help locate CSOs.  The Brian Lehrer Show on WNYC has asked listeners to map the locations of “halted development” sites.  One next step is to add this mapped data to OASIS, visualize it in the context of their surrounding neighborhoods and land use, and invite OASIS’s users to add more information about the sites to build a more complete data set.  If the Parks Department’s street tree census data is added to OASIS, residents and business owners could see each tree near their property and upload more precise information about location and condition to help the city care for the trees.  This and more is possible with OASIS 2.0.

Will OASIS continue to provide value for another 10 years?  That’s hard to answer, but it’s worth revisiting a strategic plan developed in 2004-06. One of the reports prepared for the plan noted that for some people, “OASIS is a web site, purely and simply.”  Others noted that the project has facilitated coalitions and networking on issues around open space in the city that otherwise would not have occurred.  The project offers a unique opportunity for users to interact with a mix of data about both social and physical geography that is not otherwise available in one location online.  Its value as an educational resource cannot be underestimated, serving as a research tool for students from grade school through graduate school, as well as a tool for adults to utilize visual data for planning and advocacy.  Perhaps most important, use of the website and participation in the partnership is free, and both provide great value.

If the environment that allowed these ingredients to come together and flourish continues, it’s likely that OASIS will continue.  It will evolve and take on different constituencies, but if history is a guide, this evolution will add to the project’s strengths and value.


Two people at CUNY work closely with Romalewski on the OASIS project: David Burgoon, application architect for the CUNY Mapping Service, and Christy Spielman, GIS and graphic design professional.  Burgoon completely reprogrammed and recoded the OASIS site, and Spielman has been involved with OASIS since its inception, responsible for much of its cartographic and web designs, data management, partnerships, and overall guidance.

Steven Romalewski directs the CUNY Mapping Service at the Center for Urban Research, CUNY Graduate Center. His 25-year career has centered around accessing, understanding, analyzing, and publicizing data for public policy development, community planning, and research purposes. He lives in Chelsea, Manhattan.

The views expressed here are those of the authors only and do not reflect the position of The Architectural League of New York.


Richard Shepard September 24, 2009

Everyone interested in this should hurry to the Exhibition of the Mannahatta Project at the City Museum of New York which closes Oct 12th! 5th Avenue and 103rd St.

Issac Maez December 24, 2009

I’ve been reading a few posts and really and enjoy your writing. I’m just starting up my own blog and only hope that I can write as well and give the reader so much insight.

cynthia nardin May 25, 2015

oaisis nyc map no longer seems to be available. Why?