1. (a) RFPGs shall perform future condition flood risk analyses for the region comprising:

   1. (1) flood hazard analyses that determines location, magnitude and frequency of flooding;
   2. (2) flood exposure analyses to identify who and what might be harmed within the region; and
   3. (3) vulnerability analyses to identify vulnerabilities of communities and critical facilities.

2. (b) RFPGs shall perform a future condition flood hazard analysis to determine the location of both 1.0% annual chance and 0.2% annual chance flood events as follows:

   1. (1) collect data and conduct analyses sufficient to characterize the future conditions for the planning area based on a "no-action" scenario of approximately 30 years of continued development and population growth under current development trends and patterns, and existing flood regulations and policies based on:

      1. (A) current land use and development trends and practices and associated projected population based on the most recently adopted state water plan decade and population nearest the next RFP adoption date plus approximately 30 years or as provided for in guidance;
      2. (B) reasonable assumptions regarding locations of residential development and associated population growth;
      3. (C) anticipated relative sea level change and subsidence based on existing information;
      4. (D) anticipated changes to the functionality of the existing floodplain;
      5. (E) anticipated sedimentation in flood control structures and major geomorphic changes in riverine, playa, or coastal systems based on existing information;
      6. (F) assumed completion of flood mitigation projects currently under construction or that already have dedicated construction funding; and
      7. (G) other factors deemed relevant by the RFPG.
   2. (2) identify areas within each FPR where future condition hydrologic and hydraulic model results are already available and summarize the information;
   3. (3) utilize best available data, hydrologic and hydraulic models for each area;
   4. (4) where future condition results are not available, but existing condition hydrologic and hydraulic model results are already available, the RFPGs shall modify hydraulic models to identify future conditions flood risk for 1.0% and 0.2% annual chance storms based on simplified assumptions utilizing the information identified in paragraph (1)(A) of this subsection.
   5. (5) prepare a map showing areas of 1% and 0.2% annual chance of inundation for future conditions, the areal extent of this inundation, and the sources of flooding for each area.
   6. (6) prepare a map showing gaps in inundation boundary mapping and identify known flood-prone areas based on location of hydrologic features, historic flooding, and/ or local knowledge.

3. (c) future condition flood exposure analysis. The RFPGs shall use the information identified in the future condition flood hazard analysis to develop and perform high-level, region-wide and largely GIS-based, future condition flood exposure analyses to identify who and what might be harmed within the region for, at a minimum, both future condition 1.0% annual chance and future condition 0.2% annual chance flood events as follows:

   1. (1) analyses of existing and future developments within the future condition floodplain and the associated flood hazard exposure; and
   2. (2) to include only those flood mitigation projects with dedicated construction funding scheduled for completion prior to the next RFP adoption date plus 30 years or as provided for in guidance.

   3. (3) Identification of flood prone areas associated with the hazard exposure analyses shall be based on analyses that rely primarily on the use and incorporation of existing and available:

      1. (A) FIRMs or other flood inundation maps and GIS related data and analyses;
      2. (B) available hydraulic flood modeling results;
      3. (C) model-based or other types of geographic screening tools for identifying flood prone areas; and
      4. (D) other best available data or relevant technical analyses that the RFPG determines to be the most updated or reliable.

4. (d) Future condition vulnerability analysis.

   1. (1) RFPGs shall identify resilience of communities located in flood-prone areas identified in the future condition flood exposure analysis utilizing relevant data and tools.
   2. (2) RFPGs shall identify vulnerabilities of critical facilities to flooding by looking at factors such as proximity to a floodplain, proximity to other bodies of water, past flooding issues, emergency management plans, and location of critical systems like primary and back-up power.

5. (e) All data produced as part of the future condition flood hazard analysis and future condition flood exposure analysis shall be summarized in the RFP in accordance with guidance provided by the EA and shall include:

   1. (1) underlying flood event return frequency;
   2. (2) type of flood risk;
   3. (3) county;
   4. (4) HUC8;
   5. (5) existing flood authority boundaries;
   6. (6) Social Vulnerability Indices for counties and census tracts; and
   7. (7) other categories to be designated by the EA.
6. (f) The information developed by the RFPG under this section shall be used to assist the RFPG establish priorities in subsequent planning tasks, to identify areas that need FMEs, and to efficiently deploy its resources.

Source Note:The provisions of this §361.34 adopted to be effective June 10, 2020, 45 TexReg 3792.