(a) The RFPGs shall perform existing condition flood risk analyses for the region comprising:
- (1) flood hazard analyses that determines location, magnitude and frequency of flooding;
- (2) flood exposure analyses to identify who and what might be harmed within the region; and
- (3) vulnerability analyses to identify vulnerabilities of communities and critical facilities.
(b) RFPGs shall perform existing condition flood hazard analysis to determine the location and magnitude of both 1.0% annual chance and 0.2% annual chance flood events as follows:
- (1) collect data and conduct analyses sufficient to characterize the existing conditions for the planning area;
- (2) identify areas within each FPR where hydrologic and hydraulic model results are already available and summarize the information;
- (3) utilize best available data, hydrologic and hydraulic models for each area;
- (4) prepare a map showing areas identified by the RFPG as having an annual likelihood of inundation of more than 1.0% and 0.2%, the areal extent of this inundation, and the sources of flooding for each area; and
- (5) 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.
(c) The RFPGs shall develop high-level, region-wide and largely GIS-based, existing condition flood exposure analyses, using the information identified in the flood hazard analysis to identify who and what might be harmed within the region for, at a minimum, both 1.0% annual chance and 0.2% annual chance flood events as follows:
- (1) analyses of existing development within the existing condition floodplain and the associated flood hazard exposure;
- (2) for the floodplain as defined by FEMA or as defined by an alternative analysis if the FEMA-defined floodplain is not considered best available; and
- (3) may include only those flood mitigation projects with dedicated construction funding and scheduled for completion prior to adoption of the next state flood plan.
- (4) all existing condition flood exposure analyses shall consider the population and property located in areas where existing levees or dams do not meet FEMA accreditation as inundated by flooding without those structures in place. Provisionally accredited structures may be allowed to provide flood protection, unless best available information demonstrates otherwise.
(5) In accordance with guidance to be provided by the EA, the existing condition flood exposure analyses shall consider available datasets to estimate the potential flood hazard exposure including, but not limited to:
- (A) number of residential properties and associated population;
- (B) number of non-residential properties;
- (C) other public infrastructure;
- (D) major industrial and power generation facilities;
- (E) number and types of critical facilities;
- (F) number of roadway crossings;
- (G) length of roadway segments; and
- (H) agricultural area and value of crops exposed.
- (6) The existing condition flood exposure analyses shall include a qualitative description of expected loss of function, which is the effect that a flood event could have on the function of inundated structures (residential, commercial, industrial, public, or others) and infrastructure, such as transportation, health and human services, water supply, wastewater treatment, utilities, energy generation, and emergency services.
(d) Existing condition vulnerability analysis
- (1) RFPGs shall identify resilience of communities located in flood-prone areas identified as part of the existing condition flood exposure analyses, utilizing relevant data and tools.
- (2) RFPGs shall identify vulnerabilities of critical facilities to flooding by looking at factors such as proximity to a floodplain or other bodies of water, past flooding issues, emergency management plans, and location of critical systems like primary and back-up power.
(e) All data produced as part of the existing condition flood exposure analysis and the existing condition vulnerability analysis shall be summarized in the RFP in accordance with guidance provided by the EA and shall include:
- (1) underlying flood event return frequency;
- (2) type of flood risk;
- (3) county;
- (4) HUC8;
- (5) existing flood authority boundaries;
- (6) Social Vulnerability Indices for counties and census tracts; and
- (7) other categories as determined by RFPGs or to be designated by the EA.
- (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 §361.33 adopted to be effective June 10, 2020, 45 TexReg 3792.