Community Disaster Resilience Zones Designations for Tribal Nations

FEMA’s initial designations targeted the census tracts identified as disadvantaged communities that are most at-risk to natural hazards. Although thirty-nine census tracts that overlap with tribal lands were identified in initial designations, these were not chosen specifically because they contained Tribal Nation lands. Due to the depth of need and severity of risk faced by Tribal Nations, and in response to feedback received in an official Tribal Consultation, FEMA is designating additional tracts specifically for these communities, with at least one census tract designated per federally recognized Tribal Nation.

FEMA used a collaborative approach to designate 20 percent of the census tracts that overlap with each Tribal Nation’s lands as Community Disaster Resilience Zones. Twenty percent reflects the greater risk and need faced by Tribal Nations in relation to the states (1 percent) and the territories (10 percent). The collaborative approach promotes sovereignty and self-determination by combining national datasets developed by FEMA and Tribal Nations’ self-certified data and Indigenous knowledge.

In addition to sovereignty and federal treaty and trust responsibilities, FEMA is taking a collaborative approach because currently available risk data tailored to Tribal Nation lands is insufficient. The National Risk Index (NRI), a key data source for designating zones for the states and the District of Columbia, is calculated at the State-County census tract level but Tribal Nation lands do not align with State-County census tracts. This means that the level of risk faced by non-tribal areas within a census tract can skew the overall risk score for that tract, potentially misrepresenting the level of risk faced by Tribal Nations. Section 206 of the Stafford Act requires FEMA to designate zones at the census tract level, and where available, FEMA used tribal census tracts to ensure maximum benefits to Tribal Nations. To capture the full extent of tribal lands across the county, FEMA used state-county census tracts to supplement tribal census tracts for tribal land outside of tribal census tracts.[4] FEMA is continuing to work with Tribal Nations to identify land area representation for zone designation purposes.

There are additional data challenges associated with assessing risk in tribal lands. Tribal Nations face less accurate and more limited 2020 Census data than other communities. There is a misalignment between building structure data and some Tribal Nation building types (Hazus 6.0). Additionally, historic loss ratios are underreported in tribal areas. In short, data challenges and the Administration’s commitment have informed this collaborative, CDRZ zone co-designation approach.

Designation Methodology for Tribal Nations

Step 1: Identifying Tribal Nation Lands Using a Combination of Tribal and State-County Census Tract Boundaries

To identify Tribal Nation lands using U.S. Census data, FEMA started with tribal census tracts and then used the Pairwise Erase tool provided by ArcGIS to obtain all 2023 American Indian, Alaska Native, and Native Hawaiian (AIANNH) areas that do not intersect with 2023 tribal census tract boundaries.

With the remaining shapes, FEMA used AIANNHCE (American Indian/Alaska Native/Native Hawaiian Area Code) values as a filter to obtain the set of federally recognized tribal lands without tribal census tract representation. FEMA then merged these shapes with the 2023 tribal census tract boundaries into a single feature class in a new geodatabase. The resulting product was the geographical baseline for identifying Tribal Nation lands and designating census tracts, as section 206 of the Stafford Act requires. This baseline was adjusted as needed in consultation with Tribal Nations to ensure that their lands were properly reflected in FEMA’s datasets.

Step 2: Calculate Expected Annual Loss Exposure Values for Every Tribal Nation

FEMA then calculated Expected Annual Loss (EAL) Exposure values for every Tribal Nation within each of their eligible census geometries. FEMA began by spatially joining all fields from all tribal features obtained in Step 1 to the 2020 census blocks they intersect with along with their respective NRI v1.19 census block data fields for Composite EAL and Exposure. For tribal census tracts, we aggregated Composite EAL values across the census blocks within their boundaries.

Similarly, for tribal lands without tribal census tract representation, FEMA grouped census blocks by their associated AIANNH GEOID and 11-digit census tract Federal Information Processing Series (FIPS) code and aggregate Composite EAL values for each consequence type. This generates EAL values for the intersected areas between 2020 US census tracts and tribal lands that lie outside of the 2023 tribal census tract boundaries.

Step 3: Calculate Total Annual Expected Loss Rate

Next, FEMA used the Composite EAL and Exposure values obtained in Step 2 to calculate EAL Rate percentile rankings across the eligible census geometries within each Tribal Nation. To do this, FEMA calculated Interim Total EAL rates. Then FEMA used these values to rank the eligible census geometries within each Tribal Nation.

Step 4: Coordinate and Confirm Identified Tracts with Tribal Nations

FEMA then identified the top 20 percent (by EAL rate) of the ranked eligible census geometries from Step 3.[5] For Tribal Nations without formal boundaries, FEMA identified the census tract with the Tribal Nation’s headquarters. If the Tribal Nation has multiple headquarters, FEMA worked with the Tribal Nation to identify the primary headquarters for this purpose.

FEMA then invited Tribal Nations to revise the initial tract selections as appropriate, considering local knowledge and self-certified data. Tribal Nations were not confined to designate tracts on their federally recognized lands. For example, a Tribal Nation could choose to designate a census tract where many of its members reside, even if that is not on its federally recognized lands.

FEMA designated the final selections, within the 20 percent cap, for each Tribal Nation.

Community Disaster Resilience Zones Designations for U.S. Territories

U.S. territories—American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands—are treated as states under the Stafford Act, and section 206 of the Stafford Act requires that FEMA designate at least 1 percent of the census tracts in each territory as CDRZ. U.S. territories were not included in the first set of designations, announced in September 2023, so that FEMA could prioritize meaningful engagement with territorial stakeholders.

FEMA used a collaborative approach to designate 10 percent of the census tracts in each territory. To reach 10 percent, FEMA first identified the top 20 percent of total census tracts by highest risk, using the best available data for each territory, ensuring that each tract is identified as disadvantaged by the Council on Environmental Quality’s Climate and Economic Justice Screening Tool (CEJST). FEMA then worked collaboratively with each region and territory to select amongst the identified tracts, reducing the total to 10 percent. FEMA designated a greater percentage of tracts in the territories than tracts in states and D.C. (1 percent) because data quality for the territories is inconsistent and territories are, in general, at greater risk than the 50 states and D.C. The methodology for selecting 10 percent is based on the requirement in section 206 of the Stafford Act to “consider making designations in coastal, inland, urban, suburban, and rural areas.”

FEMA is taking a collaborative approach because currently available risk data for the territories is insufficient and unreliable. For example, the Community Resilience component of the National Risk Index (NRI) is unavailable for Puerto Rico and both the Community Resilience and Social Vulnerability components of the NRI are unavailable for American Samoa, Commonwealth of the Northern Marianas, Guam, and the U.S. Virgin Islands. Data for various natural hazards are incomplete for many of the territories as well.

Designation Methodology for U.S. Territories

Step 1: Identify Census Tracts Meeting Risk-Based Designation Criteria

NRI data are incomplete for territories. To address this gap, FEMA used the following approach to identify census tracts that are most at risk to natural hazards:

1. Puerto Rico – FEMA used the Expected Annual Loss component of the NRI and the Center for Disease Control Social Vulnerability Index. [6]
2. American Samoa, Guam, Northern Mariana Islands, and US Virgin Islands – Due to many data limitations, FEMA used NRI - Expected Annual Loss data.

Step 2: Incorporate Climate & Economic Justice Screening Tool Information

CEJST datasets are only available for 2010 Census tracts. To identify disadvantaged 2020 Census tracts, FEMA used the Census Relationship file to crosswalk 2010 and 2020 Census tracts. During this data harmonization, FEMA identified a 2020 Census tract as disadvantaged if the overlapping area contains tracts with a minimum of 1% land area overlap. Any census tracts with a total land area overlap less than 1% of its own total land area were excluded.

These datasets were then joined to the NRI census tract dataset using the 2020 Census tract Federal Information Processing Standard (FIPS) codes. The resulting dataset contains all the necessary fields for the CDRZ designation.

Step 3: Preliminarily Identify the Top 20 Percent Most at Risk Census Tracts

To preliminarily identify potential CDRZ, FEMA:

1. Multiplied each territory’s total census tracts by 20 percent. [7]
2. Removed from consideration all 2020 census tracts that were not identified as disadvantaged in Step 2.
3. Ranked the remaining census tracts by the Expected Annual Loss component of the NRI (for Puerto Rico, Social Vulnerability was included).
4. Identified the top ranked census tracts equal to the calculation from 1 above.
5. Passed the identified census tracts to step 4.

Step 4: Coordinate with Each Territory to Select 10 Percent of Total Census Tracts

FEMA then invited each territory to select among the preliminarily identified tracts, reducing the total to 10 percent of each territory’s total census tracts (see below), considering local knowledge and data.

1. American Samoa – 2 tracts
2. Commonwealth of the Northern Mariana Islands – 3 tracts
3. Guam – 6 tracts
4. Puerto Rico – 99 tracts U.S.
5. Virgin Islands – 4 tracts

Next Steps / Future Directions

FEMA will announce the next group of Community Disaster Resilience Zones in 2025. Future Community Disaster Resilience Zone designations will continue to be data-driven and dependent on updates to data included in both the National Risk Index and any other element as determined by the President. CEJST is no longer included in the designation methodology. In addition, future designations will consider recommendations and feedback provided by the 2023 Request for Information published in the Federal Register as part of implementing the CDRZ Act.