(a) 1% Annual Chance Flood Event--Flood event having a 1% chance of being equaled or exceeded in any given year, also referred to as the base flood or 100-year flood.
(b) 0.2% Annual Chance Flood Event--Flood event having a 0.2% chance of being equaled or exceeded in any given year, also referred to as the 500-year flood.
(c) Board--The governing body of the Texas Water Development Board.
(d) Critical Facilities--Facilities and infrastructure that are critical to the health and welfare of the population and that are especially important following flood hazard events.
(e) Emergency Need--The need for projects and actions to address a flood hazard that is expected to cause the loss of function of critical facilities or to alleviate immediate threat to life and property from flooding such as imminent anticipated failure of infrastructure.
(f) Executive Administrator (EA)--The Executive Administrator of the TWDB or a designated representative.
(g) FEMA--Federal Emergency Management Agency
(h) FIRM--Flood Insurance Rate Map
(i) Flood--A general and temporary condition of partial or complete inundation of normally dry land area from overflow of inland or tidal waters or from the unusual and rapid accumulation or runoff of surface waters from any source.
(j) Flood-prone--Areas with known risk of flooding primarily during storm events either from existing inundation maps, studies, and/or historic knowledge of flood events. Flood-prone areas may include, but are not limited to, the floodplain, the floodway, the flood fringe, wetlands, riparian buffers, or other areas adjacent to the main channel.
(k) Floodplain--That area of land subject to periodic inundation by floodwaters.
(l) Floodplain Management--The operation of an overall program of corrective and preventative measures for reducing risk and impact of flooding.
(m) Flood Mitigation--The implementation of actions, including both structural and non- structural solutions, to reduce flood risk to protect against the loss of life and property.
(n) Flood Management Evaluation (FME)--A proposed study to identify and assess and quantify flood risk or identify, evaluate, and recommend flood risk reduction solutions.
(o) Flood Management Strategy (FMS)--Flood risk reduction solution ideas and strategies that do not belong in FME or FMP categories. Examples may include regulatory enhancements, development of entity-wide buyout programs, and public outreach and education.
(p) Flood Mitigation Project (FMP)--A proposed project, both structural and non-structural, that has a non-zero capital costs or other non-recurring cost and that when implemented will reduce flood risk, mitigate flood hazards to life or property.
(q) Flood Planning Region (FPR)--A geographic area designated by the Board pursuant to Texas Water Code §16.062.
(r) Flood Risk--Generally describes the hazard from flood events to life and property, including the likelihood of a hazard occurring; the magnitude of the hazard; the number of people and properties exposed to the hazard; and the vulnerability and resilience of the people and properties exposed to the hazard.
(s) Flood Risk Map--A map that shows flood risk for Texas communities at some level of detail using best available data.
(t) GIS--Geographic Information System
(u) GLO--General Land Office
(v) HUC--Hydrologic Unit Code level (e.g., HUC10) as delineated by the United States Geological Survey.
(w) Hydrologic and Hydraulic Model--Mathematical model created utilizing computer software that simulates rainfall runoff flow to estimate the extent of water levels and flooding and to test potential ways to reduce flood risk.
(x) Nature-based Flood Mitigation--Mitigation approaches involving the use of natural features, materials, and processes to reduce the risk and impacts of flooding.
(y) Neighboring Area--Any area, including but not limited to upstream and downstream areas, potentially affected by the proposed FMP.
(z) Negative Effect--An increase in flood-related risks to life and property, either upstream or downstream of the proposed project. The RFPG may adopt a standard that is more restrictive than the standard provided in TWDB guidance.
(aa) Planning Group Sponsor--A political subdivision designated by the Regional Flood Planning Group as authorized to receive funds for developing or revising regional flood plans. A Planning Group Sponsor must have legal authority to conduct procurement of professional services and enter into the contracts necessary for regional flood planning.
(bb) Political Subdivision--County, city, or other body politic or corporate of the state, including any district or authority created under Article III, Section 52 or Article XVI, Section 59 of the Texas Constitution and including any interstate compact commission to which the state is a party and any nonprofit water supply corporation created and operating under Chapter 67 of the Texas Water Code.
(cc) Potentially Feasible Flood Mitigation Project or Potentially Feasible Flood Management Strategy--An FMP or FMS that is assessed or considered to be permittable, constructible, economically viable, and implementable.
(dd) Regional Flood Plan (RFP)--The plan adopted or amended by a Regional Flood Planning Group pursuant to Texas Water Code §16.062 (relating to Regional Flood Plans) and this chapter.
(ee) Regional Flood Planning Group (RFPG)--A group designated by the Board that develops a Regional Flood Plan, pursuant to Texas Water Code §16.062.
(ff) Residual Risk--The remaining flood risk in an area after the completion of an FMP or FMS or set of FMPs or FMSs that reduce flood risk in that same area.
(gg) State Flood Plan (SFP)--The most recent State Flood Plan adopted or amended by the Board under Texas Water Code §16.061 (relating to State Flood Plan).
(hh) State Flood Planning Database--A database to be developed and maintained by the TWDB that stores data related to Flood Planning. It is used to collect, analyze, and disseminate regional and statewide Flood Planning data.
(ii) State Population Projections--Population projections contained in the most recently adopted State Water Plan as further assembled geographically based on HUC watershed or other appropriate flood-related geographic features determined by the TWDB.
(jj) TWC--Texas Water Code
(kk) TWDB--Texas Water Development Board

Source Note: The provisions of this §361.10 adopted to be effective June 10, 2020, 45 TexReg 3792; amended to be effective November 1, 2023, 48 TexReg 6360