CRS Explorer Tool Helps Communities

The CRS Explorer Tool helps communities:

Visualize Hero


Visualize areas that currently qualify for Open Space Preservation (OSP) credit alongside the points they provide.



Identify potential future OSP-eligible areas in the floodplain, alongside the potential points they provide.

Communicate Hero


Communicate flood risk and the importance of conserving floodplains to residents and decision-makers

The tool is designed to be used by county and city planners, as well as floodplain managers, land trusts and conservation organizations.

How it Works:

Up until a few years ago, CRS Coordinators had few resources available to help them map and visualize areas within their community’s floodplain that are eligible to earn CRS points for Open Space Preservation. Over the last decade, a variety of tools have emerged to support communities that want to calculate their OSP points but aren’t quite sure how.

The basic process to calculate Open Space Preservation points is to calculate the area of the community’s special flood hazard area that is under the regulatory control of the community. This means that Federally managed areas and open water bodies must be removed before calculating the area. Communities identify undeveloped parcels within their dataset through zoning, land class/use code or other indicator within their data and further identify if these parcels are protected from development by evaluating protected area status, conservation easements and land use restrictions. OSP are calculated base upon how much of the adjusted special flood hazard area (or “floodplain”) is undeveloped land that is protected by regulation to prevent infilling and development. NOAA developed a great resource that provides more detail on How-To Map Open Space Preservation for Community Rating System Credits. The “How-To” guide describes a stepwise workflow to help planners and GIS specialists identify eligible OSP parcels and calculate potential CRS credits.

The CRS Explorer Tool displays the outputs from the NOAA GIS workflow (provided the user packages the data into a geodatabase as described in the GIS Workflow) and allows the user to identify potential future OSP-eligible areas in the floodplain. The CRS Explorer tool allows the user to explore how many points a parcel, if protected from development, could earn for the Community’s CRS rating.

What are the Strengths and Limitations?

Tool Strengths:

  • The tool displays the total CRS credits available within Activity 420: Open Space Preservation.
  • The tool allows the user to explore scenarios of future land preservation to understand how many more potential points the community could earn towards Activity 420.
  • The tool uses and displays the outputs from the NOAA GIS workflow for mapping OSP.
  • The tool is accessible and easy to use.

Tool Limitations:

  • The tool estimates potential credits. It is based on best available data, but does not represent a final analysis or score, and must be verified by the NFIP’s CRS Insurance Service Office (ISO) representative.
  • It only identifies areas eligible for the CRS Activity 420 OSP elements. It is the responsibility of the applicant to determine other points the community could receive in other activity and element categories.
  • The quality of the resulting analysis is dependent upon the data provided by the community; communities are responsible for acquiring data, completing the GIS workflow, and validating the outputs. For communities with limited capacity, TNC and/or Digital Coast Partners might be able to help your community to complete the GIS workflow.

Where is it Being Used?

Communities in North Carolina, South Carolina, Georgia, Florida, Mississippi and Texas have used this tool to identify eligible and potential future Activity 420 OSP points. To learn more about the CRS Explorer tool and how it can help your community earn CRS points, click here.

Who Helped Develop it?

The CRS Explorer is based on an idea that a county planner in North Carolina had during collaboration with the North Carolina Chapter of The Nature Conservancy. It was piloted to eight communities within Dare and Hyde Counties. Across those eight pilot communities, there were on average 546 eligible OSP points that were not currently identified and credited in these CRS communities.

This revealed the immediate value of existing preserved open space, allowing some to improve a class which results in an additional 5% off flood insurance premiums for policyholders in the floodplain. Since then, the tool has been expanded upon and improved to support visualizing and planning for new protections of open space in the floodplain.

Digital Coast partner organizations including The Nature Conservancy (TNC), NOAA’s Office for Coastal Management (OCM), Association of State of Floodplain Managers (ASFPM), American Planning Association (APA) and the Coastal States Organization (CSO) are investing in the development of tools and guides to support communities in applying for CRS credits. In 2020, the original CRS Explorer which existed as an App on TNC’s Coastal Resilience tool was redeveloped as a standalone web-based mapping tool, the CRS Explorer Tool. This transition allowed more communities (especially communities with mostly or only riverine flooding) to more easily access and use the CRS tool.