86Th Legislative Session State Flood Assessment Report to the 86Th Texas Legislature

State Flood Assessment

Report to the Legislature

86th Legislative Session State Flood Assessment Report to the 86th Texas Legislature

Peter M. Lake, Chairman Kathleen Jackson, Member Brooke T. Paup, Member

Jeff Walker, Executive Administrator

January 2019

www.texasfloodassessment.com www.twdb.texas.gov

Table of Contents

Executive summary �� 2 1 Introduction �� 4 2 Texas floods �� 7 2.1 Types of floods �� 7 2.2 Precipitation influences �� 8 2.3 Geography of floods �� 9 2.4 Benefits of floods �� 11 3 Flood risk �� 12 3.1 Flood risk to Texans �� 12 3.2 Flood risk to the economy �� 14 3.3 Future risk �� 15 3.4 Awareness in Texas �� 15 4 Floodplain management and mapping �� 16 4.1 What is a floodplain? �� 16 4.2 Mapping a floodplain �� 16 4.3 Mapping the regulatory floodplain �� 18 4.4 Mapping needs in Texas �� 20 5 Planning for floods �� 22 5.1 Current planning efforts in Texas �� 22 5.2 Approaches used in other states �� 25 5.3 Elements of sound planning �� 27 6 Flood mitigation in Texas �� 29 6.1 Types of flood mitigation activities �� 29 6.2 Cost of mitigation �� 31 6.2.1 Anticipated mitigation costs �� 32 6.2.2 Available mitigation funding �� 32 6.2.3 Mitigation funding shortfall �� 33 6.3 Funding sources �� 34 6.3.1 Local funding �� 34 6.3.2 State and federal funding �� 35 7 Roles and other considerations �� 37 1 7. Responsibilities for flood mitigation �� 37 2 7. Barriers to implementation �� 40 3 7. Synergies with water supply �� 42 8 Preliminary findings and stakeholder priorities �� 43 8.1 Preliminary findings �� 43 8.2 Limitations and uncertainties in estimating costs �� 43 8.3 Stakeholder priorities �� 44 8.4 Impact of doing nothing �� 47 8.5 Benefits of acting now �� 47 8.6 Laying a foundation with science and data �� 47 9 Recommendations to the 86th Texas Legislature �� 48 9.1 Background �� 48 9.2 Specific flood recommendations and further background �� 48 References �� 51

State Flood Assessment | Texas Water Development Board 1 Executive summary

Though Texas has experienced organized according to three key Emergency Management Agency flooding throughout its history, pillars of comprehensive flood (FEMA) to establish insurance losses of life and property in risk management: (1) mapping, rates, these maps currently are recent years—from the 2015 (2) planning, and (3) mitigation. the state’s most utilized tool for Memorial Day Flood in Wimber- assessing flood risk. Based on ley to Hurricane Harvey along Flood risks, impacts, and FEMA data and the State of Texas the Gulf Coast region in 2017— mitigation costs have nev- Hazard Mitigation Plan, roughly 1 highlight the state’s vulnerabilities. er been assessed at the in every 10 Texans is exposed to These disasters, along with six oth- statewide level. Texas has a moderate or high risk of riverine er federally declared flood decla- long and storied history of flood flooding each year; coastal flood- rations since 2015, call attention to events, but until this effort by the ing is projected to become the the need for a clearer understand- Texas Water Development Board costliest weather-related hazard ing of flooding in Texas, from the (TWDB), the state’s risks and to the state; and more than half events themselves to the resources needs have not been evaluated. of recent flood insurance claims needed to mitigate them. For the foundation of this as- occurred outside of areas identi- sessment, we conducted surveys, fied as high-risk flood zones. This report provides an initial workshops, and meetings with assessment of Texas’ flood risks, stakeholders across the state, the Much of Texas is either un- an overview of roles and respon- results of which, both quantita- mapped or uses out-of-date sibilities, an estimate of flood tive and qualitative, are integral maps, leading to wide- mitigation costs, and a synopsis to better preparing for future spread confusion. Mapping of stakeholder views on the future Texas floods. is the first step in identifying and of flood planning. It does not communicating flood risk. FEMA’s seek to fund specific strategies or Flood risks pose a serious flood insurance rate maps show projects related to flood planning, threat to lives and live- the boundary of inundation for mitigation, warning, or recovery. lihoods. Most communities the 1 percent annual chance Preliminary findings summarized in Texas use Flood Insurance flood event—commonly referred in this assessment are derived Rate Maps (FIRMs) to commu- to as the 100-year flood and from stakeholder input and nicate local flood risk. Created often misinterpreted as the line and maintained by the Federal

2 Texas Water Development Board | State Flood Assessment between safe and not safe. How- impacts in upstream or down- assistance for implementation of ever, these maps may not reflect stream communities. Stakeholders flood mitigation activities; (2) im- flood conditions based on the expressed a preference for locally provements to flood risk mapping most current topographic, land led flood planning at a watershed and modeling; and (3) a prefer- use, or rainfall data. Creating scale. This sentiment is consis- ence for collaborative, locally led, flood risk maps using the most tent with stakeholder calls for watershed-based flood planning. recently collected scientific data increased collaboration, coordi- In addition, the TWDB heard and models for all watersheds in nation, and leadership among all a call to expand educational the state could cost up to $604 entities with flood responsibilities. outreach and technical assistance million. Stakeholders prioritized Watershed-based planning seeks opportunities throughout the up-to-date flood risk mapping, to identify multi-benefit solutions state. These priorities emerged including collection and distri- to common flooding problems from myriad suggestions and bution of supporting data and and to bring about efficiency in reflect areas of broad consensus addressing local drainage issues. implementing projects. among stakeholders.

Rainfall drives most flood Significant funding is re- Sound science and data events in Texas, but rainfall quired to mitigate flooding are the core elements of data used to inform planning in Texas. Though the responsi- effective planning and flood and design are decades old. bility to prepare for and mitigate mitigation. Through support An updated version of the rainfall flood impacts is primarily local, from the Office of the Governor depth-duration-frequency data most communities do not have and the Texas Legislature, the (Atlas 14, Volume 11) used to the economic resources required TWDB has implemented new model and predict how frequently to accomplish their goals. Stake- initiatives in recent years to a specific flood event might reoc- holders engaged with this assess- better prepare the state for flood cur was published in September ment cited funding to support events. To continue expanding 2018. The data showed that in implementation of mitigation proj- these efforts and to improve areas with significant increases in ects as their greatest need. Antic- data collection, mapping, estimated rainfall, flood risks are ipated statewide flood mitigation and monitoring of conditions likely to be greater than previously costs over the next 10 years are across the state, the agency has thought. However, new analyses estimated to be more than $31.5 requested an additional $4.45 and modeling will be needed to billion. Due to potential shortfalls million in appropriations from the determine the impacts these up- in local funding, communities 86th Texas Legislature. dated rainfall estimates may have. may need access to an estimated $18.0 to $26.6 billion in finan- The TWDB’s legislative Texas does not have a cial assistance. These estimates flood recommendations. The statewide strategic plan to account only for mitigation costs legislature should pursue proac- address flood risk manage- based on stakeholder input. tive statewide flood mitigation ment. Flood mitigation involves They do not account for projects by first developing foundational any combination of actions taken associated with Hurricane Harvey flood risk management policies to prevent or reduce the impacts recovery, other large federal proj- and goals that will support of flood events. Though individual ects such as the Coastal Spine, three key pillars of investment: planning efforts take place across or rehabilitation of high hazard (1) improved and updated flood the state, there is no unified, co- dams within the state. mapping and modeling; (2) coor- ordinated process to assess and dinated watershed-based plan- plan for the state’s flood-related Stakeholders identified ning; and (3) mitigation efforts, needs. As such, project imple- the need for additional such as policy enhancements, mentation occurs piecemeal. resources directed toward increased technical assistance, Mitigation without sound scientific floodplain management and financial assistance for data, proper mapping, and coordi- and mitigation. Specifically, project implementation. nated planning may be ineffective stakeholders requested in order or, worse, may intensify flood of priority: (1) additional financial

State Flood Assessment | Texas Water Development Board 3 To date, Texas has never conducted a statewide assessment 1. Introduction of flood risks and needs. Floodwaters rise and fall on every Input from stakeholders across Texas forms the foundation creek, draw, bayou, coast, and riv- of this report. er shoreline in Texas at some point Stakeholders identified a need for greater investment in time. Floods, like drought, are in mapping, planning, and mitigation—three pillars of a natural part of the water cycle. comprehensive flood risk management. During a drought we anxiously await a rain event big enough to that remains today (Slade and flooding along the San Marcos, finally end the dry spell. A drought Patton, 2003; NWS, 2018a). Guadalupe, and San Antonio buster arrives eventually. But rain Widespread rainfall in the spring rivers (Slade and Patton 2003). events large enough to end a of 1957 broke a statewide, Most recently in August and drought, as well as smaller events, multi-year drought of record but September 2017, Texans witnessed can lead to flooding. also brought flooding across the the continuous rain bands of On September 9, 1921, an state from the Pecos to the Sabine Hurricane Harvey unleash up to intense but short-lived downpour (TBWE, 1957; TWRI, 2011; 60 inches of rain over 8 days, occurred in Williamson County. Burnett, 2012). In October 1998, causing devastation for residents The small town of Thrall received a stalled front brought up to 30 from Rockport to Orange, some more than 36 inches of rain in 18 inches of rain to south-central of whom are still recovering today hours, setting a national record Texas in two days, causing historic (Watson et al., 2018).

Stakeholder input The Texas Water Development Board conducted extensive outreach to floodplain administrators and stakeholders in the spring of 2018 to gather both qualitative and quantitative information to form the basis of this assessment. Two surveys, eight regional workshops, numerous conversations at water-related conferences, and individual meetings with eight state and federal agencies allowed many Texans to contribute to this effort.

We conducted surveys in two phases. First, we distributed an initial survey to all stakeholders via email and online. Then, we sent a second, more detailed survey to stakeholders who self-identified as willing to provide additional information, particularly about the financial component of flood mitigation. For outreach purposes, we divided the state into 12 watershed-based regions generally corresponding to the state’s major river basins and conducted workshops in seven of these regions (Figure 1.1).

Stakeholders from across Texas were well-represented by this process. Survey 1 received 1,026 individual responses, and Survey 2 received 208 individual responses. Most respondents (69 percent) identified themselves primarily as public-sector employees who hold flood-related responsibilities for their community, nearly 43 percent of whom identified as floodplain administrators. Both small communities and urban centers were well represented in both surveys. Specifically, small communities represented 38 percent and 40 percent of total respondents, respectively, for Surveys 1 and 2. Across the 12 regions, Survey 1 captured responses representing up to 45 percent of communities within each region. Additionally, the eight workshops attracted a total of 267 attendees. Lastly, we offered an opportunity for stakeholder input by soliciting public review and comment, receiving 89 comments. The comment period included the October 3 meeting of the TWDB where the public was invited to provide comments in person.

Survey responses, workshop data, and public comments are posted as online appendices to this report at www.TexasFloodAssessment.com.

4 Texas Water Development Board | State Flood Assessment Figure 1.1 Stakeholder outreach was organized by 12 watershed-based regions generally corresponding to the state’s major river basins. Stakeholder workshops were held in March and April 2018 in Arlington, Austin, Corpus Christi, El Paso, Houston, Lubbock, McAllen, and Nacogdoches.

! Lubbock

Arlington !

! El Paso Nacogdoches !

Austin ! Houston !

Outreach regions Brazos, Lower Brazos, Upper Corpus Christi ! Colorado, Lower Colorado, Upper East Texas McAllen Houston - Coastal ! Nueces - South Coastal Plains Panhandle Red River Rio Grande San Antonio - Guadalupe Trinity ! Workshop cities

Anywhere it rains in Texas, it expensive hazards in the state are property losses—or 41 percent of can flood—a lesson that we anticipated to result from severe the projected economic loss from often forget too quickly. Despite coastal flooding, hurricanes and all natural hazards during this extensive flood awareness and tropical storms, or riverine flood- period (TDEM, 2018). mitigation efforts, flooding is a ing. Coastal and riverine flood- hazard that remains. Through ing combined are expected to On July 31, 2018, the President 2023, three of the top five most cause more than $6.87 billion in signed into law the Consolidated

State Flood Assessment | Texas Water Development Board 5 Appropriations Act of 2018, myriad components related to management and mitigation as which reauthorized the National flood disaster readiness, emer- well as on training and education Flood Insurance Program (NFIP) gency operations, or response. needs. Often constrained by a through November 30, 2018, lack of financial resources, stake- In the summer of 2016, discourse but did not address the more holders believe that increased began with stakeholders and the than $20 billion shortfall facing financial support will enhance legislature on the need for a state the program (USGAO, 2018).* existing local floodplain man- flood plan—a long-term strategic The federal government formal- agement efforts and will allow for document to identify flood mitiga- ized the current framework for greater leverage of funding from tion needs and solutions to reduce managing flood-prone lands federal programs. Further, they flood risk statewide. Subsequently, in 1968 with passage of the suggest that the best approach with funding provided by the National Flood Insurance Act for mitigating flood risk involves 85th Texas Legislature, the TWDB a solid foundation of science and creating the NFIP. Through three conducted a survey of floodplain complementary efforts—flood flood risk mapping upon which administrators and related stake- collaborative planning can be hazard mapping, floodplain holders to better understand flood management regulations, and used to better inform mitigation planning, mitigation needs, and strategies. The TWDB concurs flood insurance—the NFIP aims associated costs for communities to reduce risk to human life and with this viewpoint. Thus, this first across the state. This State Flood State Flood Assessment is orga- damage to property (44 CFR Assessment represents the out- nized according to such a linear Chapter I, Subchapter B). However, come of that process. progression of effort—mapping, despite 50 years of concerted planning, mitigation—to serve as effort and extensive participation The information presented in a roadmap for flood risk man- by Texas communities, we find this assessment is derived from agement across Texas. ourselves repairing and rebuilding stakeholder input and is organized instead of planning and preventing. according to the three areas of need they described as being * On December 7, 2018, the President most important: (1) increased signed legislation passed by Congress Why a statewide state resources for implementation that extends NFIP’s authorization to assessment? of mitigation activities, which may December 21, 2018. include support for policy con- Texas is the second most popu- siderations, increased technical lous state and the second largest assistance, and data collection; in terms of land area. We also (2) improved and updated flood currently rank second behind mapping activities; and (3) Louisiana in terms of flood-related coordinated, watershed-based damage payments. Despite these flood planning. facts, there has never been a thorough statewide assessment Stakeholders consistently voiced of flood risk, flood planning, or a need for the state to support the need for mitigation activities investments in these areas. and financial assistance in Texas. Though the TWDB estimated While aspects of flood risks are financial costs for such invest- assessed in both local hazard ments from a variety of sources, mitigation plans and the State we relied solely on stakeholder of Texas Hazard Mitigation Plan input when deriving anticipated (TDEM, 2018), neither addresses costs and funding shortfalls for the full spectrum of complexi- mitigation and infrastructure needs. ties that characterize our flood issues. This assessment likewise Captured as vignettes throughout, does not address all aspects of this assessment includes addition- flood protection, such as the al stakeholder input on floodplain

6 Texas Water Development Board | State Flood Assessment 2. Texas floods Flooding is a natural phenomenon that impacts all areas of the Floods are a natural and regular that killed 22 percent of local state. occurrence, having shaped the residents and destroyed almost Texas landscape for millennia. all structures (Tufts, 2017). The Rainfall is the driver of most flood events, The main attraction at the Waco hurricane that struck Galveston in though land use change Mammoth National Monument is 1900 killed an estimated 6,000 can magnify its impacts. fossilized remains of mammoths people and created a 15-foot Updated rainfall that perished in floodwaters—an storm surge that destroyed most frequency estimates, estimated 67,000 years ago. structures (Ramos, 1999). Histor- released in September Early settlers experienced flooding ically, all areas of the state have 2018, show parts of the as a frequent hazard. The Mission been and continue to be impact- state will be affected by San Antonio (the Alamo) was ed by flooding (USGS, 2001). In increased rainfall. moved twice to avoid destruction fact, each of our 254 counties from floods: first in 1719 and has endured at least one federally snow. Due to our state’s varied again in 1724 (Schoelwer, 2018). declared flood disaster, according landscape and location along the The City of Houston, incorporated to FEMA. Clearly, living in Texas Gulf of Mexico, Texas’ version of in August 1836, experienced its comes with some risk of flooding. the water cycle frequently results first recorded flood in April 1837 in flooding, with rainfall serving as (Johnston, 1991). The first cabin the driver of most events. The pri- in what would eventually become 2.1 Types of floods mary types of flooding that impact the City of Dallas was damaged The water cycle, also called the the state are summarized below. in a flood along the Trinity River hydrologic cycle, is the natural Riverine flooding – Abundant in 1844 (Butler, 2011). Entire process by which moisture from rainfall can result in more runoff towns have been wiped off the oceans and other water bodies entering a river channel than map or moved. In 1882, the town moves into the atmosphere as can be contained within its banks. of Ben Ficklin (then the coun- evaporation and then falls back When water levels exceed the ty seat of Tom Green County) down to land as precipitation in capacity of a channel, the river experienced extreme flooding the form of rain, sleet, hail, or overflows onto adjacent lands,

Visitors to Waco Mammoth National Monument can view fossilized remains of mammoths that perished during a flood approximately 67,000 years ago.

State Flood Assessment | Texas Water Development Board 7 called the floodplain. On steep, to arrive roughly one to two 2.2 Precipitation narrow floodplains, these excess days after it passes underneath overflows can create flood condi- Interstate 35. influences tions suddenly (see flash flooding Culturally, Texas is viewed as a below). Where land is flat and Coastal flooding – Low pres- dry state perpetually lacking rain sure systems may gain strength floodplains are more expansive, and plagued by drought. Yet, Tex- as they travel across the warm greater volumes of runoff are as holds the record for the highest waters of the Gulf of Mexico, required to cause flooding, the rainfall totals for an individual sometimes developing into impacts of which may take hours or storm recorded in the contiguous tropical storms or hurricanes. As days to reach locations downstream United States. The 60.58 inches these systems approach the Texas (see slow-rise flooding below). of rainfall recorded at Nederland, coast, stronger winds combined Texas, during Hurricane Harvey with changes in water surface Flash flooding – A type in 2017 broke the single tropical elevation can produce a storm of riverine flooding, flash storm record for the United States, surge that drives ocean water in- flooding is characterized by which was set in 1950 in Hawaii land across the flat coastal plain. a short time lag (less than (Blake and Zelinsky, 2018; NWS, High tide events also may cause six hours) between the rain 2018c). Rainfall intensity and du- frequent, localized flooding of event and rapidly rising water ration records in Texas approach low-lying coastal lands. levels (NWS, 2018b). Flash the maximum values recorded flooding can occur anywhere Stormwater flooding – This anywhere in the world (Slade, rainfall intensity exceeds the type of localized flooding occurs 1986; Asquith, 1998). infiltration capacity of the soil, when rainfall overwhelms the causing rapid surface runoff. capacity of engineered drainage To better prepare, we rely on Areas with large amounts of systems to carry away rapidly historical records and rainfall pat- impervious surfaces, exposed accumulating volumes of wa- terns to model and predict future bedrock, or other solid surfac- ter. It typically dissipates quickly, rainfall, subsequent flood events, es that reduce infiltration and except in situations such as when and potential impacts. These data increase runoff, are especially pumping equipment fails due are also used to create infrastruc- susceptible to flash flooding. to loss of power, inflows exceed ture design standards. Atlas 14, Near El Paso, runoff from pumping or conveyance capac- compiled by the National Weather steep slopes flows rapidly ity, or debris blocks the passage Service, provides estimates of over dry, impenetrable soils of water. The solid surfaces of the maximum rainfall that can be transporting and depositing buildings and streets (also called expected for most locations in the eroded materials across the impervious cover) prevent rainfall United States, based on histori- landscape. from soaking into the ground, re- cal rainfall measurements (NWS, Slow-rise flooding – This sulting in runoff. Because this type 2018d). An update to Atlas 14 second type of riverine flood- of flooding is most common in ur- for Texas (Volume 11) was re- ing occurs when rain events ban environments, it is sometimes leased in September 2018 (NWS, near the top of the water- called urban flooding. 2018e), incorporating decades shed, or far upstream, cause of additional rainfall data, im- Structural failure flooding – flooding that continues un- proving the accuracy of rainfall Though uncommon in Texas, abated downstream, impact- information, and superseding failure of man-made infrastructure, ing communities where no all previous estimates for rain- such as dams or levees, can occur rain fell. For example, slow- fall events in the state (primarily when intense or extensive rainfall rise flooding occurs along the USDC, 1961; USDC, 1964; results in the uncontrolled release Guadalupe River. When in- NOAA, 1977). of floodwaters. Failures may arise tense rains in the Hill Country if a rain event exceeds the design cause the river to swell in New Atlas 14, Volume 11, which capacity of a structure, such as Braunfels, the City of Victoria, incorporates data from Hurricane when Callaway and McGuire located 230 river miles down- Harvey, shows increases of more dams failed in Robertson County stream, can expect floodwater than 5 inches for the 1 percent in May 2004 (TDEM, 2013).

8 Texas Water Development Board | State Flood Assessment This map of Texas shows the amount (in inches) that 100-year, 24-hour precipitation estimates have increased when comparing the new NOAA Atlas 14 estimates with the old TP-40 estimates. Sep. 27, 2018

Figure 2.1 Comparison of new rainfall values to old estimates (NOAA, 2018). annual chance, 24-hour rainfall floodwaters. In general, for 2.3 Geography event in areas near Houston, as areas where rainfall estimates compared to existing historical have been lowered, there will be of floods records (NWS, 2018e). Elsewhere greater confidence that exist- Texas rivers are born of the water in Texas, new rainfall estimates ing infrastructure will perform from surface runoff or groundwater also may differ significantly. Del as intended. In areas where discharge and take shape as they Rio, San Antonio, Austin, and estimates of rainfall have been erode, transport, and deposit Corpus Christi are some of the raised, flood risks are likely to be sediments over many miles in areas where the depths of rainfall greater than previously anticipat- their journey toward the Gulf of associated with many storms are ed. Increased rainfall totals over Mexico. Beyond their headwaters expected to increase (Figure 2.1). a short time span means that and moving downstream, rivers storms will have more significant widen and meander as they drain Although the rainfall frequency impacts than previously predict- more and more land area. Texas data have been updated, ad- ed, thereby translating to larger has 15 major river basins, each ditional studies are needed to discharges of water into drain- with unique combinations of pre- determine the consequences of age ditches and under bridges, cipitation and evaporation pat- changes in the estimates. New larger volumes of water in de- terns, geologic and topographic analyses will be required to tention ponds and behind flood features, and local soils, vegeta- determine and revise the extent control structures, and larger tion, and land use practices. In of flood inundation that can be regulatory floodplains associat- addition, eight designated coastal expected and the appropriate ed with a specific duration and basins, nested between each design standards for infrastruc- frequency of storm. major river basin, drain the nearly ture to withstand or convey flat coastal plain (Figure 2.2).

State Flood Assessment | Texas Water Development Board 9 Figure 2.2 Major river basins and subbasins of Texas. A river basin, also called a watershed, is an area of land whose runoff drains to a common outlet.

Canadian

Red

Sulphur Cypress Trinity Sabine Brazos

Neches Colorado Rio Grande San Jacinto

Lavaca Neches-Trinity Nueces Trinity-San Jacinto San Jacinto-Brazos Brazos-Colorado Colorado-Lavaca Lavaca-Guadalupe Nueces-Rio Guadalupe Grande San Antonio San Antonio-Nueces

In Far West Texas where intense has led to the development of result in runoff that is quickly con- but infrequent rains fall on steep numerous flood control structures centrated in the river channels of slopes and crusted soils hardened (Wermund, 1996). narrow floodplains. Floodwaters by the sun, water runs off quickly here tend to be deep, fast, and and powerfully—often carving An area known as “Flash Flood highly erosive (Caran and Baker, new paths across the landscape. Alley” stretches from Del Rio 1986). Moving northward toward Flash flooding and stormwater across to San Antonio and then the metroplex, short-duration, flooding events are most common up through Waco to the Dal- high-intensity rain events also there. However, the history of ex- las-Fort Worth metroplex. In the result in flash flooding, especially tremely large flood events on the southern portion of this region, in urbanized areas. Rio Grande, a river whose basin the steep terrain, shallow soils, drains more than 48,000 square and constricted river channels In the Panhandle, storms may miles, is well documented and carved into the Edwards Plateau cause local flooding in and

10 Texas Water Development Board | State Flood Assessment around playa lakes and in the flow of rivers and streams, slow- Flood events provide numerous urbanized areas of this region. In ing the outflow of surface runoff ecological benefits, including the East Texas, flood events typically from the land and further aggra- maintenance of habitats for many arrive slowly and can linger for vating flooding in the low-lying plants and animals, the exchange days or even weeks before swol- coastal plain. of nutrients and organisms len rivers return to normal. between the main river channel and floodplain, and the deposi- Most of our major rivers drain the 2.4 Benefits tion of sediments, nutrients, and Coastal Plain as they meander of floods organic matter that enrich soils toward the Gulf of Mexico. As the (TIFP, 2008; MEA, 2005). Certain Floods are part of the natural en- rivers approach the flat topog- species are adapted to the natu- vironment. They shape and form raphy of the coast, they typically ral rhythm of floods and depend the natural floodplains along slow down and spread out. This on their regular occurrence to streams and rivers, which in turn can result in expansive but shallow complete their life cycles. The ag- provide flood risk reduction ben- flooding in this region. Living at or ricultural sector also may benefit efits such as storing excess water, from improved soil fertility via the near sea level also means exposure reducing peak flows, and slowing sediments and nutrients depos- to the possibility of coastal flood- runoff (FEMA, 2018a). Vegetation ited by floodwaters. As a result, ing from wind-driven storm surge on floodplains slows the rate of floods, particularly those of lower and extreme precipitation associ- overland flow, which also acts to magnitude that occur regularly, ated with tropical storm systems. reduce flood peaks and erosion. provide numerous benefits. Elevated ocean and bay water Slower runoff can lead to in- surface levels during such events creased infiltration and recharge may counteract the downstream of aquifers in certain areas.

Rivers in Texas can experience both flash floods and slow-rise floods.

State Flood Assessment | Texas Water Development Board 11 3. Flood risk Flood events are common but only capture our attention Nearly every Texan faces some when they impact lives and livelihoods. level of risk related to flooding. At least 2.8 million people (11 percent of Texas’ population) The flood risk in any community, are exposed to high or moderate riverine flood risk. regardless of the type of flood- A majority of recent flood insurance claims occurred ing, reflects a combination of outside of high-risk flood zones. natural and human-made factors. Severe coastal flooding is projected to become the costliest Though flood risk is ever-pres- hazard to Texas in the coming years. ent, flood events usually garner attention only when impacts affect well, with rapid growth in the area people facing such risk of riverine our livelihoods by destroying along the Interstate 35 corridor flooding, with most of those Texans crops, buildings, roads, bridges, potentially exacerbating risk in living in the high-growth Lower Rio vehicles, or worse, causing injury this region. Grande Valley (Figure 3.1). or death. About 95 percent of floodplain Of the 12 weather-related hazards administrators surveyed reported investigated during development 3.1 Flood risk that they determine and commu- of the State of Texas Hazard to Texans nicate flood risk in their commu- Mitigation Plan, riverine flooding A key to understanding flood nity using Flood Insurance Rate accounted for 7 percent of aver- risk in Texas is the State of Texas Maps (FIRMs). Created and main- age annual property losses from Hazard Mitigation Plan, which is tained by the Federal Emergency 1996 through 2016. TDEM’s updated every five years by the Management Agency (FEMA), plan also includes hazard impact Texas Department of Emergency and discussed in the next chapter, forecasts for the 2019 through Management. The report inves- FIRMs identify areas exposed to 2023 time-period, during which tigates weather-related hazards moderate or high-risk of riverine riverine flooding is expected to that regularly impact the state or coastal flooding. The TWDB account for 8 percent of all annual by examining financial and other used data gleaned from FIRMs to property losses and 6 percent of impacts to people and property describe flood risk in Texas and all crop losses (TDEM, 2018). (TDEM, 2018). Of particular to explore the reasons why Texans interest to this assessment are data cannot fully rely on FIRMs alone Risk from coastal flooding to understand flood risk. presented on riverine flooding and High or moderate coastal flood severe coastal flooding; stormwa- risk, also displayed on FIRMs, ter and structural failure flooding Risk from riverine flooding poses the greatest threat, again, are not covered by that report. Based on available FIRMs and to the Houston-Coastal and the The mitigation plan reveals that 2010 census data, an estimated Nueces-South Coastal Plains the Houston-Galveston-Beaumont 2.8 million people, or 11 percent regions. Note that within the Haz- region experiences the most of the state’s population, are ard Mitigation Plan, storm surge frequently occurring and costly exposed to high or moderate risk damages are examined under property damage from severe of riverine flooding in any given severe coastal flooding; whereas, coastal flooding as compared to year. The Houston-Coastal region hazards posed by hurricanes and the rest of the state, owing to its has the most residents exposed, tropical storms are associated high population density and vast with 23 percent of the 2010 popu- with wind impacts. Severe coastal petrochemical industry. Central lation living or working in one flooding accounted for 25 percent Texas, well known across the of these risk zones. The Nuec- of the average annual property nation for flash flooding, expe- es-South Coastal Plains region loss across the state from 1996 riences frequent flood losses as has nearly the same percentage of through 2016. This type of flooding

12 Texas Water Development Board | State Flood Assessment is projected to surpass all other Risk from stormwater response operations. FIRMs do weather-related hazards, including flooding not capture this type of localized hurricanes and tropical storms, Impacts from stormwater flood- flooding; therefore, historical to become the costliest hazard to ing include damage to vehicles, impacts and current risk posed by the state in coming years (TDEM, structures, roads, and related stormwater flooding are difficult 2018). TDEM anticipates $5.6 drainage infrastructure. Road- to quantify. Communities typically billion in potential property losses ways pose an additional threat develop master drainage plans to from coastal flooding during the if drivers, unaware of the depth identify and address issues related period from 2019 through 2023, of flooding, proceed through the to stormwater flooding, but the accounting for 34 percent of all water. Similarly, flooded roads statewide picture of exposure from expected weather-related losses prevent and limit emergency this hazard remains incomplete. (TDEM, 2018).

Figure 3.1 Population projections for 2050 by subbasins corresponding to U.S. Geological Survey 8-digit Hydrologic Unit Code (HUC). Texas has 207 HUC-8 subbasins (TWDB, 2018).

Population projections in 2050 by HUC-8 (subbasin) < 250,000 250,000 to 500,000 500,000 to 1,000,000 > 1,000,000

State Flood Assessment | Texas Water Development Board 13 Residual risk time the map was created, any trade for nearly a week as the Residual risk relates to the likeli- land use, development, or mitiga- main highway between Laredo, hood of flood impacts occurring tion changes that occur after map Texas, and Nuevo Laredo, Mexico, remained submerged, strand- within an area despite the pres- publication are not accounted for. ing people, trucks, and goods ence of a nearby flood control Further, the binary presentation of (USDA, 2010). structure. Sources of residual flood risk on FIRMs conveys the sense that if one is outside the risk are most often associated The threats to livelihoods, reduction demarcated 100-year flood zone with flood events that exceed in purchasing power, impacts to there is no risk of being flooded. the design capacity of a levee, critical infrastructure, and loss of dam, or drainage system, as property values associated directly opposed to those resulting from 3.2 Flood risk to and indirectly with flooding may actual structural failure. Though increase economic risks to commu- quantifiable, it often is presumed the economy nities. A recent analysis by Standard to be negligible or non-existent, Commerce exists near water when & Poor’s Financial Services (2018) creating a false sense of security. flows are considered depend- noted that improper planning for The National Levee Database able, but flood events can disrupt weather-related risks can impact identifies nearly 2 million Texans a local economy, both in the a municipality’s credit rating, subject to residual flood risk immediate aftermath of an event with specific emphasis on hazard associated with levees (USACE, and over longer time-periods. impacts to the local population 2018). No such data exists for Damages to critical infrastructure and the associated tax base. the residual risk to Texans associ- such as bridges, roads, water This analysis also called out the ated with dams. and wastewater treatment plants, importance of realistic financial critical care facilities, and power assumptions and projections that A non-conventional source of plants may lead to vital service account for the disruptions caused residual risk is related to the interruptions, causing ripple effects by natural hazards and the benefits static nature of FIRMs and how upon the economy in the affected from implementing mitigation strat- information is presented on these area and nearby region long after egies to increase resiliency. Further, maps. Because FIRMs are in- floodwaters recede. For example, recurrent flooding may discourage tended to represent the flood risk in 2010, flooding along the Rio long-term investments by the gov- associated with conditions at the Grande disrupted international ernment and private sector alike.

Historic flooding during Hurricane Harvey in 2018 caused billions of dollars of damage in Houston and other coastal communities.

14 Texas Water Development Board | State Flood Assessment 3.3 Future risk Similarly, in the same time-period Administration (NOAA) since severe repetitive loss claims, as 2004, the National Weather Ser- Texas is projected to increase identified by FEMA, occurred in vice’s Turn Around, Don’t Drown™ from 29.7 million people in 2020 every major river basin in the campaign is perhaps most to 42.3 million by 2050 (TWDB, state, except for the Canadian familiar to Texans. The campaign 2018). Much of this growth will basin, totaling 6,776 such highlights the danger of driving occur upstream and downstream properties statewide. Frequency or wading into floodwaters (NWS, of major metropolitan areas of claims and losses for these 2014). The Texas Department of (Figure 3.1). According to U.S. perpetually flooded properties Transportation employs the well- Census data, Texas grows by over mirrored those described above. known message on road signs, a thousand people each day. social media, and other venues. Without a concerted focus on In the absence of a full statewide The Texas Floodplain Manage- “encouraging sound land use by flood risk analysis, the TWDB ment Association also uses it in minimizing exposure of property relied on these insurance claims public outreach materials, includ- to flood losses,” per Texas Water data, plus hazard impact projec- ing a poster illustration contest for Code § 16.312, it stands to rea- tions, to understand our risk. If grade school students. son flood events will impact more the past is any indication, these lives and cause more damage in numbers reveal a concerning While these collective efforts the future. trend. Stakeholders likewise noted encourage safe behaviors and that despite ongoing efforts, more reduce the need for emergency According to FEMA data, since resources are devoted to disaster response, the need remains for 1978 Texans have filed more than recovery than to proactive miti- long-term educational campaigns 361,000 flood insurance claims gation and damage prevention. to increase pre-situational aware- totaling just over $15.7 billion in Further, recent flood events across ness. Efforts to teach the public to damages. Just over half of those the state and newly released Atlas understand flood risk within their claims, representing $12.7 billion 14, Volume 11, revised precipi- watershed can be accomplished in damages, have been filed since tation estimates suggest that the by developing user-friendly web- 2008. Further, 53 percent of frequency—and therefore the sites and publications based on the more recent flood insurance risk—of being flooded may be observed data from local, mem- claims occurred outside of high- greater than Texans realize. orable events and general flood- risk flood zones. plain management concepts. FEMA defines repetitive loss as These campaigns could also re-in- properties that have flooded 3.4 Awareness in terpret flood risk data to better two or more times with a claim Texas communicate the true potential for payment of $1,000 or more. Flood awareness encompasses inundation by floodwaters. Flood Between 1978 and 2018, 48 knowledge of basic concepts maps for public education could percent of repetitive loss claims of the water cycle, watershed display the full spectrum of risk occurred outside of mapped science, weather patterns, flood from various sized riverine and high-risk flood zones. The Hous- risks, and emergency prepared- coastal flood events and—where ton-Coastal and East Texas ness and response. Most public possible—communicate the po- regions had the greatest number education campaigns, however, tential risk of stormwater flooding. of repetitive loss properties within focus only on situational aware- To prevent loss of life and damage the state, with the San Jacinto ness and preparedness in the to property to the greatest extent River basin being particularly event of a flood. Recent events possible, Texans must understand hard hit. Other basins with high across the state point to wide- that the high-risk zone shown on numbers of repetitive loss prop- spread confusion related to the a flood insurance rate map relates erties included, in descending meaning of the 100-year flood to the requirement to purchase order, the San Jacinto-Brazos and (further explained in Chapter 4). flood insurance. It does not de- Neches-Trinity coastal basins and marcate whether one is safe or not the Trinity, Brazos, and Guadalupe Officially trademarked by the Na- safe from the next flood event. river basins. tional Oceanic and Atmospheric

State Flood Assessment | Texas Water Development Board 15 4. Floodplain management and mapping

Flood hazard mapping is the first step in identifying flood- Floodplain management encom- prone areas and communicating risk to stakeholders. passes any part of the strategic effort to identify areas subject The regulatory floodplain is distinct from the natural floodplain. to flooding and to protect the natural function of those areas. Floodplain maps are complex and are often misinterpreted. Flood risk mapping represents the critical first step in identifying For the past 50 years, regulatory line, much like the demarcation flood-prone lands and in com- oversight for floodplain manage- for a 0.2 percent annual chance municating that information to ment has followed the principle flood event—commonly termed residents, decision makers, and that adequate flood protection a 500-year flood—instead shows emergency responders. In Texas, for the public can be achieved by the boundary of potential inun- complementary efforts focused building infrastructure and adopt- dation from a very specific flood on flood risk mapping, planning, ing floodplain ordinances to pro- event based on the land use con- and mitigation do not exist. This tect against a flood event with a 1 ditions that existed when the mod- chapter explains the differences percent probability of occurring in eling and mapping were complet- between a natural and a regula- any year. Because such an event ed. Beyond either boundary line, tory floodplain and describes the has a 1-in-100 chance of occur- the risk of flooding still exists, just process and applications of flood ring or being exceeded in any with a lower probability of occur- risk mapping—the first pillar of given year, the phrases 100-year rence. As noted previously, any sound flood risk management. flood and 100-year-floodplain are land use changes subsequent to commonly used. However, these the modeling alter the movement colloquial terms are misleading. of water and thus the probability 4.1 What is a Their use stems from a simplifica- of flooding. floodplain? tion of the statistical process for calculating the probable recur- A floodplain is the land adjacent rence of flood events of a given 4.2 Mapping a to a water body that is subject to magnitude. Neither term is meant inundation during a flood. The floodplain to indicate that such a flood event size and shape of a floodplain Understanding the extent of will occur only once per 100 influences the characteristics of the natural floodplain can be years. It is quite possible for a a flood event. The boundaries of accomplished by observing local 100-year flood to occur several a natural floodplain can change conditions. Rivers carry and leave years in a row. In fact, for a struc- with each flood event as sedi- behind fine sediments during ture exposed to this likelihood of ments are scoured and deposit- floods. The presence of such flooding, the statistical probability ed within the river channel and sediments, deposited repeatedly of incurring flood damage during upon adjacent lands. Similarly, over time, denotes an area that the span of a 30-year mortgage the coastal shoreline changes was previously inundated and equals 26 percent. frequently. A regulatory flood- may be subject to inundation in plain, however, is determined by Further, the boundary of the 1 the future. Every county in Texas modeling a specific storm event percent annual chance flood has a detailed soil survey showing and depicting the boundaries of event, shown on a FIRM as locations of frequently flooded inundation resulting from that the special flood hazard area soils (see the Natural Resources storm on a map. As a result, a (SFHA)—another name for the Conservation Service (NRCS) regulatory floodplain only changes regulatory floodplain—often is Web Soil Survey at https:// when a new study or mapping misinterpreted as a dichotomy websoilsurvey.nrcs.usda.gov/). effort is conducted. between safe and not safe. That Similarly, the University of Texas

16 Texas Water Development Board | State Flood Assessment Bureau of Economic Geology of local flood hazards, on their between when the rain falls and maintains an archive of surface own these observational signs when the resulting runoff reaches geology map sheets where are inadequate for certain map- the stream. alluvium, or sediments deposited ping activities unless properly by moving water, can indicate the surveyed. Whereas hydrologic models extent of historical flooding. simulate the quantity and timing In floodplain management, engi- of the flow of water, hydraulic Along river edges, riparian neers and hydrologists investigate models simulate the forces that ecosystems withstand, and in channel or shoreline features affect water flow, specifically how fact rely on, periodic inundation to determine how floodwaters friction and pressure interact to by floodwaters. Similarly, stable will move. They also use hydro- determine the height to which dune systems along the coast logic and hydraulic modeling floodwaters will rise. Here, the support certain plant species to provide the detailed analyses characteristics of the stream that when absent indicate shore- required for specific design, channel itself—as opposed to the line areas subject to frequent construction, and regulatory ap- watershed—are most important. change and thus heightened plications. Hydrologic modeling For coastal storm surge analysis, flood risk from wave action. In considers how the unique charac- three-dimensional hydrodynamic the aftermath of a flood, the teristics of a watershed (the soils, circulation models are used to height of floodwaters can be surface geology, terrain, land use, evaluate wave height. Together, determined via high water marks etc.) respond to a rain event or these models can describe the in- left on walls of homes or detritus how much rain will soak into the undation, or spread and depth of left perched in trees, bridges, soil versus run off into drainage water over the floodplain, associ- and even road signs. Though systems and rivers. These mod- ated with the storm event selected useful to building a narrative els also estimate the lag time for analysis.

Purpose of the National Flood Insurance Program (NFIP) The NFIP operates by voluntary agreement between the federal government and local political subdivisions (cities, counties, villages, special purpose districts, and tribal nations, hereafter referred to as communities). Established by Congress in 1968 and administered by FEMA, the NFIP aims to mitigate future flood damage through three efforts:

Flood mapping. FEMA generates and approves flood insurance rate maps (FIRMs), which identify areas of high, moderate, or low-risk of flooding along rivers, the coast, and other water bodies but not for areas impacted by local drainage issues. FIRMs identify land areas with a high-risk of flooding (areas subject to inundation during a 1 percent annual chance event) denoted on the map as the regulatory floodplain or the Special Flood Hazard Area (SFHA). Participants in FEMA’s Cooperating Technical Partners program assist by identifying watersheds in need of mapping and by conducting mapping activities; however, the final approval of a regulatory floodplain map is completed by FEMA. View approved FIRMs at msc.fema.gov.

Community-enforced regulation. NFIP communities must adopt and enforce floodplain management regulations that meet or exceed FEMA’s minimum standards (for full criteria, see 44 CFR 60.3), which include issuing permits for development within SFHAs; conducting field inspections and citing violations; maintaining records of floodplain development; and assisting in the preparation and revision of FIRMs.

Flood insurance. Within NFIP communities, all residents gain the option to purchase federally backed flood insurance; however, certain homes and businesses in designated SFHAs with mortgages from federally regulated or insured lenders are required to maintain insurance. Flood insurance also can be required as a condition for receiving federal disaster aid. FIRMs are used to determine insurance premiums for properties in flood-prone areas.

State Flood Assessment | Texas Water Development Board 17 4.3 Mapping corresponding to when specific complete (Table 4.1). CTPs assist mapping activities were completed in three of the four phases of the regulatory and adopted by FEMA. When a mapping activities as laid out floodplain minor map revision within one by FEMA and must follow FEMA FEMA, with assistance from local panel is adopted, the effective Guidelines and Standards for partners, creates and maintains date of the FIRM changes even Flood Risk Analysis and Mapping FIRMs and their modern digitized though the remainder of the pan- (FEMA, 2018b). equivalents, DFIRMs. Hydrologic el reflects flood hazard informa- Phase 0 – Base level and hydraulic or hydrodynamic tion derived from older data. Or, a FIRM may be revised based on engineering consists of models, using local watershed recently acquired elevation data compiling existing data, and channel or coastal shore- (i.e., lidar, or light detection and information, and modeling line data, as described above, ranging) but still use precipitation to prioritize watersheds for are simulated to identify areas data from a previous decade. In further study and ultimately at high, moderate, or low risk of certain instances, the date shown to produce regulatory flood flooding. FIRMs show land areas on a county FIRM may not reflect hazard boundaries. To pro- subject to inundation by riverine the more recent updates of ceed to Phase 1-Discovery, flood events or coastal storm individual panels. Smith County, a watershed must have base surge for the 1 percent annual for example, shows an effective level engineering completed. chance event (high-risk or spe- date of 2008, but the City of cial flood hazard area) and the Tyler updated its panels in 2014. Phase 1 – Discovery 0.2 percent annual chance event In short, the effective date of a includes outreach and infor- (moderate risk area). FIRM may not equate to the age mation gathering within the of all data used to create the flood watershed, including infor- Only 20 percent of survey hazard zones displayed therein. mation on areas of mitigation respondents describe their interest and areas in need of detailed mapping. Detailed FIRMs as recently updated. Cooperating Technical mapping includes creation of The remaining described Partners Program their maps as old, outdated, base flood elevations. FEMA launched the Cooperating incomplete, or insufficient. Technical Partners (CTP) Program Phase 2 – Flood risk in 1999 to enhance the rate of study includes the compila- Beginning in 2003, FEMA’s map mapping activities and to increase tion of datasets for hydrology, modernization initiative sought local involvement in the process. hydraulics, infrastructure, and to digitize as many existing flood All mapping activities follow a land use, as well as existing hazard maps as possible. Figure four-phase process, which may base maps and, if available, 4.1 shows the status of FIRMs in take a minimum of 5 years to floodplain maps. A flood risk Texas, as of April 2018. Ap- proximately half of the counties in Texas had no digital flood Table 4.1 Summary of the four phases to produce a regulatory flood map, or insurance rate maps and most of FIRM, and the role of FEMA and Cooperating Technical Partners (CTPs) at each the remaining counties had not phase, plus estimated length of time to progress through each phase. updated FIRMs within the last five years. Entities authorized to Phases Production time FIRMs exist as individual panels conduct work corresponding to U.S. Geo- 0 – Base level engineering FEMA and CTPs 9 months logical Survey quadrangle and quarter-quadrangle boundaries. 1 – Discovery FEMA and CTPs 12 months At the county level, a FIRM can 2 – Flood risk study FEMA and CTPs 24 months be comprised of panels form- ing a mosaic of different dates 3 – Map production FEMA 18–24 months

18 Texas Water Development Board | State Flood Assessment DFIRM status > 10 years old (2005–2007) Between 5 and 10 years old (2008–2012) < 5 years old (2013–2018) No maps or partial paper maps Paper maps Preliminary DFIRM available DFIRM (Digital Flood Insurance Rate Map)

Figure 4.1 Type and age of Flood Insurance Rate Maps (FIRMs) by county. Digital flood insurance rate maps (DFIRMs) exist for 47 percent of Texas counties, and the majority of those were completed more than five years ago. Preliminary DFIRMs are available in some counties where initial modeling has been completed, but mapping updates have not yet been approved. Paper maps indicate flood zone designations were made prior to 2003, and the data used to create them are often much older. In certain areas, no FIRMs exist, so no flood hazard information has been determined. FIRMs are created and updated by FEMA or through partnership with one of 11 Cooperating Technical Partners (CTPs): the cities of Arlington, Austin, Dallas, Fort Worth, and Grand Prairie; the Guadalupe-Blanco and San Antonio river authorities; the Harris County Flood Control District; the North Central Texas Council of Governments; and the Texas A&M University-Texas Community Watershed Program. The TWDB supports mapping assistance for all regions of the state not represented by a CTP and serves as the state coordinator.

State Flood Assessment | Texas Water Development Board 19 study determines accurate key purpose of this flood assess- an area greater than one square surface elevations and may ment is to better understand the mile. Iowa collected the elevation include developing mod- resources needed by communities (lidar) and related channel-spe- els for riverine flooding or in Texas to properly manage flood- cific data necessary to complete coastal storm surge as well as plains and mitigate flood risks. mapping studies that meet FEMA special assessments related quality standards. In this way, the to alluvial fans and levees. A The TWDB heard from NFIP-par- Iowa Flood Center ensured the flood risk study delineates the ticipating communities that the information was made available 1 percent and 0.2 percent path to a FEMA-approved FIRM is to the public relatively quickly annual chance event inunda- arduous, often controversial, and (via a web portal used only for tion boundaries. lags behind the pace of growth non-regulatory purposes such as in their communities, thereby emergency response and pre- Phase 3 – Flood insurance limiting their ability to protect lives paredness planning) while also rate map production and property. However, an NFIP advancing efforts by NFIP par- completes the process for community has the authority to set ticipating communities to pursue developing a regulatory flood and enforce local floodplain or- updating their local FIRMs. map, including a public com- dinances. Though typically based ment period, an opportunity on FEMA-approved FIRMs, com- North Carolina chose a different for appeal and protest, and munities may choose to base their path. In 2000, North Carolina approval of the map. Phase permitting and related require- became a Cooperating Technical 3 does not involve CTPs and ments on any other best available State, as opposed to partnering is exclusively completed by data, such as preliminary FIRMs, community, and undertook full re- FEMA. existing high-water marks, his- sponsibility for collecting updated torical accounts of inundation flood hazard data and for maintaining current FEMA-approved extents, and similar information. 4.4 Mapping needs FIRMs. Through a three-phased Some communities in Texas utilize Statewide Floodplain Mapping in Texas this type of data for local planning Program, local, state, and federal Throughout Texas, flood risk and emergency preparedness. partners committed the financial, remains largely undefined and Others do not have the resourc- staffing, and technical resources unquantified. Though useful es to acquire such information necessary to successfully provide for regulatory applications and and instead wait for the FEMA updated maps for every water- flood insurance determinations, approval process. FIRMs show only the potential shed within a 10-year timeframe. Several states have taken an hazards posed by a flood event Alternative approaches to de- alternate route to flood hazard as modeled for a very specific set termining and communicating mapping. The Iowa Flood Center of conditions. Further, FIRMs do flood risk also exist. Though less completed a statewide inunda- not capture the risk of stormwa- comprehensive than the FEMA tion mapping project over the ter flooding unless a community risk mapping process, these al- course of six years by developing chooses to conduct the studies ternatives may offer a faster path their own hydraulic models and necessary to incorporate that to providing flood risk informa- mapping all streams that drain data into their hazard map. A tion for Texans. A recent effort by Wing and others (2017) developed a flood hazard model har- nessing publicly available data for the conterminous United States Stakeholders’ Top 3: financial resources and found the results compared for flood hazard mapping favorably enough to FEMA FIRMs to inform decision making at a Stakeholders identified flood hazard mapping as the second most fraction of the cost. important area for the state to invest resources.

20 Texas Water Development Board | State Flood Assessment Cost to produce the cost associated with updating flood risk or a lack of resources regulatory FIRMs FIRMs on a regular basis. For to initiate mapping activities. The An estimated cost for the state to these projects, federal grant con- TWDB prioritizes funding for flood conduct mapping activities fol- tributions provided an average of mapping projects using weighted lowing FEMA’s phased approach 26 percent of the overall cost. geospatial data aggregated to producing FIRMs for riverine according to HUC-8 watershed As the state CTP coordinator, the boundaries. Thus far, the datasets flooding in all watersheds is TWDB focuses on areas in need about $604 million. Calculated used, in order of relative impor- of mapping assistance. In 2015, tance, include lidar availability, using published FEMA cost the TWDB partnered with FEMA estimates (FEMA, 2017), this number of flood insurance claims, to fund development of a prioriti- number of repetitive and severe number includes an estimated zation tool to aid in the selection $62.4 million to conduct base repetitive loss claims, FIRM status, of watersheds for study. Using population, projected population level engineering (Phase 0); this tool, the TWDB can identify $15.6 million for discovery change, lack of a CTP, and avail- areas with needs based on an able in-kind resources that can be (Phase 1); and $525.8 million to array of factors such as a high conduct flood risk studies (Phase leveraged for the study. 2) for all watersheds in the state. The U.S. Geological Survey uses the HUC (hydrologic unit code) National Flood Insurance Program in Texas designation to describe the In 1999, the 76th Texas Legislature directed cities and counties to nested hierarchy of watersheds, adopt ordinances or orders necessary to be eligible for participation from major river basin to smaller in the NFIP (Texas Water Code § 16.3145). When communities subbasins. This cost estimate is meet eligibility requirements (44 CFR § 59.22), residents gain ac- based on conducting mapping cess to federal assistance, including federally backed flood insur- for the 207 8-digit HUC subba- ance and post-disaster assistance. sins (often called HUC-8 watersheds) in the state. As of September 2018, Texas has 1,252 NFIP participating communities: 1,011 cities, towns, or villages; 220 counties; and 21 special purpose However, some watersheds have districts, including water control and improvement districts, local improve- begun or have recently complet- ment districts, bayou improvement districts, municipal utility districts, and ed the mapping update process drainage districts. The State of Texas itself does not participate. (e.g., all of the Guadalupe and Neches river basins and other All political subdivisions are “authorized to take all necessary and individual HUC-8 watersheds), reasonable actions that are not less stringent than the requirements reducing the need to invest in a and criteria of the NFIP” (Texas Water Code § 16.315). If desired, complete remapping of the state communities can implement federal, state, or local initiatives and at this time. A true cost for devel- higher regulatory standards. The Community Rating System (CRS), oping and updating all FIRMs in a voluntary FEMA program, encourages efforts that exceed mini- Texas has yet to be determined, mum standards by offering a discount of up to 45 percent to flood insurance policy holders. Example activities that generate a discount but example costs from recent include preserving open spaces in flood-prone areas, monitoring mapping activities ranged from flood conditions and issuing warnings, and enforcing stricter devel- $1.2 million for the Lower Col- opment standards through flood damage prevention ordinances. orado Cummins basin (most of Bastrop and Fayette counties) to As of September 2018, only 62 NFIP communities in Texas were $2.6 million for Upper Brushy participating in the program. Dallas, Grand Prairie, Houston, Creek (part of Williamson Coun- Pasadena, and Plano each earn a 25 percent discount, the highest ty). These estimates include both in the state. Some Texas communities that do not participate in the state or local in-kind services CRS program have adopted higher standards via flood damage and existing data and modeling prevention ordinances, which could translate into credits and asso- products as well as federal grant ciated insurance discounts if they chose to apply. funding. Estimates do not include

State Flood Assessment | Texas Water Development Board 21 5. Planning for floods

Texas first considered the idea of a statewide planning process for Mitigation without proper mapping and coordinated planning may be ineffective, or worse—intensify flood floodplain management in 2002. impacts in upstream or downstream communities. Following a series of natural disasters, the 76th Texas Legis- Effective planning includes core elements: lature established a Blue Ribbon Data, models, and sound science Committee to examine ways to An inclusive vetting process improve state, federal, and volun- Defined levels of acceptable risk and teer coordination and to provide standardized benchmarks streamlined disaster assistance Quantifiable outcomes (BRC, 2001). This was followed by a report from the Senate Stakeholders strongly support watershed-based flood planning driven by local communities. Interim Committee on Natural Resources, which recommended statewide planning for floodplain management in its interim report unlike the early implementation evaluating their flood risks and to the 78th Texas Legislature of water supply projects prior mitigation activities. Further, (SICNR, 2002). The report also to the 1961 State Water Plan, stakeholders requested in- recommended that flood mitigation present day flood mitigation and creased support for and finan- programs be consolidated within mapping projects tend to be cial investment in coordinated, a single agency. The TWDB has locally driven and not coordinat- watershed-based flood plan- served as the state’s NFIP coordi- ed at broader regional scales. ning—a second pillar of flood nator since 2007. Although the state has yet to de- risk management. velop a common vision for flood Following the historic drought of risk management or an associ- the 1950s, the Texas Legislature ated flood planning process, this 5.1 Current planning enacted the Texas Water Plan- assessment reveals that initiatives efforts in Texas ning Act of 1957 to accomplish are already in motion in some Texas has several ongoing plan- a vision for preparing the state to parts of the state. ning efforts that address some meet the projected future water With broad consensus from flood- element of flood protection that supply needs of its rapidly grow- can be applied toward a more ing economy. This vision and its plain administrators and other stakeholders, through this assess- concerted statewide flood plan- legacy evolved over time to a ning effort. sophisticated, regionally comment the TWDB learned about prehensive evaluation of future the need for more coordinated Hazard mitigation plan- water availability and needs, with flood planning efforts and about ning. The State of Texas Haz- recommended projects to spe- the numerous options available ard Mitigation Plan provides a cifically meet those needs. Not for supporting communities in high-level overview of statewide strategies to reduce exposure to all weather-related hazards, including riverine and coastal Stakeholders’ Top 3: financial assistance flooding. Once every five years, for flood mitigation planning with guidance from the State Haz- ard Mitigation Team, the Texas Stakeholders identified flood mitigation planning as the third most Division of Emergency Manage- important area for the state to invest resources. ment (TDEM) identifies the state’s

22 Texas Water Development Board | State Flood Assessment Only half of stakeholders reported that their jurisdiction has identified flood risk and conducted local planning efforts to develop mitigation solutions. Communities, special purpose districts, and multi-jurisdictional regions accomplish this through development of plans addressing hazard mitigation, comprehensive land- use, drainage, watershed protection, emergency operations, or some combination of these efforts. priorities for funding types of had an expired local plan or no River basin planning. Re- flood hazard mitigation actions approved plan (FEMA, 2018c). gional entities and partnerships, (e.g., drainage projects, acquisi- Barriers to creation of local haz- such as development councils, tion and demolition of properties, ard mitigation plans are similar river authorities, and councils etc.) and planning projects (e.g., to those reflected in our survey of government, may conduct watershed-level mitigation plans), of stakeholders: limited financial planning activities, guide devel- as well as a repetitive loss strategy resources, lack of staff dedicat- opment, and assist local gov- of specific actions meant to reduce ed to this process, and difficulty ernments in implementing plans potential losses to properties navigating the process. regarding land use, water sup- with a history of flood damages. ply, drainage, and open spaces The 2018 State of Texas Hazard Local hazard mitigation planning, (Local Government Code, Chap- Mitigation plan was approved by given its focus on addressing all ter 391). Each river authority’s FEMA in October 2018. types of natural hazards and its enabling legislation is unique, voluntary nature, is not sufficiently but generally all have powers The state plan lays out priorities scoped to provide collaborative, related to flood control (Texas based on feasibility, cost effec- watershed-based strategic flood Constitution, Article XVI, Sec- tiveness, capacity to be executed, planning. The process, as carried tion 59). The San Jacinto River and conformance to the goals out, is important but limited. Fur- Authority publishes a basin-wide of the plan itself. The state plan ther, the entities that participate plan that includes discussion of does not compile or prioritize in this process may vary, leaving flood protection, flood control specific projects, and there is no no guarantee that participants will reservoirs, and flood retarding organized process to ensure the have experience in dealing with structures. The San Antonio River prioritized actions are implemented. flood risks. Authority has implemented holistic However, beyond local hazard preparedness benefits, the state and communities have incentive for developing hazard mitigation plans, because the plans are required for eligibility to receive federal assistance through FEMA’s Flood Mitigation Assistance (FMA), Pre-Disaster Mitigation (PDM), and Hazard Mitigation (HMGP) grant programs. Once a community’s plan is approved by FEMA, the community becomes eligible for federal assistance through these programs (TDEM 2013).

As of July 2018, 117 counties had communities with FEMA-approved hazard mitigation plans covering about 81 percent of the state’s population (D. Jackson, pers. comm.). Many communities Many Texas reservoirs were built to provide flood control.

State Flood Assessment | Texas Water Development Board 23 watershed planning across the Coastal resiliency planning. the Texas General Land Office, basin to assist the responsible The Texas General Land Office is a long-term, comprehensive local entities to manage land has developed the Coastal Resil- coastal planning effort focused use change and maintain water iency Master Plan, a multi-year, on coastal storm risk manage- quality. The effort also includes stakeholder planning process to ment and ecosystem restoration. incorporating FEMA’s Risk Map- identify structural and non-struc- As of late 2018, the USACE has ping, Assessment, and Planning tural mitigation (termed “grey” narrowed its list of viable projects (RiskMAP) approach to identify- and “green”, respectively) strate- to several storm risk management ing flood risk for every watershed gies, including policy recommen- scenarios that provide a barrier in the basin. Funding for these dations, to enhance resiliency and system for the Houston-Galveston initiatives is supported by the San to better protect coastal infra- and Galveston Bay region, plus Antonio River Authority’s ability structure, natural resources, and a suite of shoreline protection to levy an ad valorem tax, which economic activities from natural and habitat restoration projects is limited to $0.02 per $100 of hazards (TGLO, 2017). To date, along the Texas coast. The final assessed property valuation. this process has yielded a suite of feasibility report is expected to be specific projects largely focused delivered to Congress in 2021 The Texas State Soil and Water on habitat restoration and con- for consideration to authorize and Conservation Board (with support servation that can provide specific fund. Additionally, the USACE from the NRCS Watershed and starting points for expanding has announced studies of Buffalo Flood Prevention Operations comprehensive flood planning Bayou and its tributaries, as well Program) works with rural land- along the coast. as the Houston Regional Water- owners to develop watershed shed Assessment to determine protection plans to address flood The U.S. Army Corps of Engi- solutions for local flood issues. prevention, erosion and sediment neers (USACE) recognizes that Other USACE studies will con- control, and planning for priority Texas’ natural and economic sider resiliency solutions for the dams, among other activities. resources are of national impor- Brazos River in Fort Bend County Similarly, Texas A&M University tance and may be significantly and for the Guadalupe and San conducts training for watershed impacted by floods and storm Antonio river basins. planning to ensure plans meet surge. The USACE, therefore, the Environmental Protection has committed to conducting Flood protection planning. Agency’s requirements by iden- planning studies within the state. Since 1983, the TWDB has pro- tifying nonpoint source pollution The Coastal Texas Protection vided state financial assistance, and proposing local solutions to and Restoration Feasibility Study, requiring up to a 50:50 cost improve water quality. conducted in partnership with share, to communities to conduct

Severe coastal flooding is projected to become the costliest hazard to Texas in the coming years.

24 Texas Water Development Board | State Flood Assessment 5.2 Approaches used in other states Coordinated watershed-based planning occurs throughout the nation but appears in different forms among the states. State- wide flood planning, in the format of a cyclical, multi-regional evaluation to identify projects, is a relatively uncommon process. Instead, many states have chosen to focus on specific tasks, such as statewide mapping or policy implementation, to build strong floodplain management programs that can provide services and mitigation beyond those of FEMA and the NFIP alone.

California, Illinois, Iowa, Mary- land, Minnesota, Montana, Nebraska, New Jersey, Oklahoma, and West Virginia have published formal plans related to watershed-based or statewide flooding concerns, floodplain The TWDB’s TexasFlood.org displays river conditions around the state. management, or flood hazard mitigation operations. detailed studies of known or in Texas through this program. California, in partnership with potential flood-prone areas to Further, communities have been the USACE, has completed the better inform the development able to leverage their efforts from most extensive flood planning of flood protection strategies these flood protection planning effort in the nation, the outcome through structural and non-struc- studies to obtain additional fund- of which yielded California’s tural solutions. This grant pro- ing through FEMA Flood Mitiga- Flood Future Report, a compre- gram allows communities to tion Assistance grants. Consid- hensive overview of the state’s conduct hydrologic and hydraulic ering any future flood planning risk of flooding, approaches for studies of current and future con- efforts, there are elements of the mitigating risk, recommendations ditions and to identify potential TWDB’s flood protection plan- for action, and existing financial mitigation solutions, including ning grant program that can investment, as well as an esti- estimated costs and benefits. The be modeled—elements such as mate of future financial need process ensures opportunities for inclusive stakeholder forums, based on input from regional broad stakeholder education and multi-jurisdictional cooperation, entities (CDWR, 2013). input for each project, as well as modeling flood risk under future consistency with relevant plans, In 2014, Minnesota used $4.9 development conditions, identify- laws, and regulations. Between million in state funding to initiate ing structural and non-structural 1995 and 2017, over $20 mil- a watershed-based pilot pro- solutions, and requiring local lion in state funding, in addition gram to comprehensively address financial contribution through to $30 million provided in local water resources issues, including dollars or in-kind services. matching funds, was committed flooding, within six watersheds— to flood protection planning with a goal of implementing the

State Flood Assessment | Texas Water Development Board 25 program statewide by 2025. The Other states without formal, com- and seek approval for multi-ju- program operates on a 10-year prehensive flood plans emphasize risdictional, multi-hazard plans planning cycle, requires 10 specific programs related to flood on an annual basis. As a result, percent local matching funds, warning or mapping. Iowa, for Florida is one of the few states and is based on formal, voluntary example, emphasizes real-time with 100 percent coverage of partnership agreements among flood warning and inundation approved local hazard mitigation entities in a given watershed. The mapping capabilities, published plans (FEMA, 2018c). purpose is to encourage these via web-based viewers for both entities to work collaboratively the public and decision makers. Through state code, Wisconsin, to identify policies, projects, or North Carolina focuses on Washington, and Florida seek strategies to protect, enhance, or floodplain mapping; as a FEMA to lower flood risk by restricting restore their basin. An approved Cooperating Technical State, they building construction in flood- plan (whether individually or as assume ownership of their FIRMs prone areas. For example, part of this initiative) allows ac- and publish associated hazard Wisconsin requires structures cess to state funding. Without an data, models, maps, and risk to be constructed to the Flood approved plan, entities will only assessments. Oklahoma and New Protection Elevation, which is 2 have access to limited, compet- York, on the other hand, devel- feet above the base flood eleva- itive grant funding. Long-term oped statewide mesonets (weather tion (Mittler et al., 2006). Florida funding for the program is pro- monitoring networks) focused on requires uniform, comprehensive vided by revenue from a three- gathering and providing weather land use policies of all jurisdic- eighths of one percent increase in data to inform both flood response tions and enforcement of the the state sales tax. and drought forecasting. state’s minimum building codes (Brody et al., 2009). Nebraska similarly completed a Some states conduct flood statewide Flood Hazard Mitiga- planning primarily through the Funding sources used by states to tion Plan, which is used in part to FEMA hazard mitigation planning implement and maintain flood- determine whether local mitiga- process, which can potentially plain management activities are tion activities are effective (NDNR, increase access to additional as varied as the programs de- 2013). The Iowa Watershed resources from FEMA. As of scribed above. All states utilize Approach program coordinates June 2018, 12 states, including available federal funding, though watershed management author- California, Florida, Iowa, North some, such as Florida, have ities and encourages local wa- Carolina, Washington, and implemented activities that enable tershed-based planning through Wisconsin, had comprehensive access to greater post-disaster voluntary interlocal agreements mitigation programs along with a federal funding. Many strong (IWA, 2017). FEMA-approved Enhanced State state programs across the U.S. Mitigation Plan. Approval allows were developed following natural Most existing flood plans, how- access to additional Hazard disasters, whether directly through ever, do not recommend specific Mitigation Grant Program funds federal funding or through each projects for funding and are not (FEMA 2018). To achieve this state’s own commitment to im- supported by dedicated state status, a state must demonstrate prove preparedness. funding sources. Maryland’s flood an ability to effectively use avail- Following disastrous flooding in damage vulnerability assessment, able funding and to manage for example, requires commu- 2008, Iowa used a combination increased funding (44 CFR § of a $15 million grant from the nities to submit annual lists of 201.5). Texas is currently seeking projects and watershed-wide U.S. Department of Housing to earn this same status. Florida and Urban Development (HUD), flood damage plans to receive also maintains a delegation of supplemental state funding, but $2.2 million from the U.S. Army authority from FEMA to approve Corps of Engineers Planning the associated grant program local hazard mitigation plans via does not have a dedicated, reli- Assistance to States, existing the Program Administration by state and federal commitments able funding source (Joyce and States pilot initiative. Florida thus Scott, 2005). for lidar data collection, and requires all counties to update a portion of $2 million in state

26 Texas Water Development Board | State Flood Assessment floodplain management funds responded to Hurricane Floyd in entities. Using $1.2 billion in (allocated over several years) to 1999 by allocating $25 million funding from HUD, the state will support floodplain mapping and the following year to establish a begin implementing a variety of the production of FIRMs for 86 floodplain mapping program. activities for strong floodplain percent of the state. Iowa also The state has since partnered management (LWI, 2018). took advantage of a $97 million with FEMA to become a Coop- HUD disaster resilience grant erating Technical State. In the to create the Iowa Watershed first nine years of the program, 5.3 Elements of Approach program. The Iowa North Carolina mapped 100 sound planning Flood Center, founded following percent of watersheds, investing Natural resources planning the 2008 floods, continues the a total of about $70 million represents an agreement among state’s efforts to map floodplains, and receiving $73 million from parties to identify the purpose, provide flood-inundation maps, FEMA. The state maintains this objectives, and paths to im- and maintain a network of stream program via a transaction fee plementation (Fallding, 2008). flow sensors for communicating associated with the recording of The purpose of flood planning, potential risk of flooding to the deeds and mortgages. generally speaking, is to manage public. The state provides an flood risk in a fiscally viable way. annual budget of approximately In May 2018, Louisiana’s Gover- However, flood planning conducted $1.2 million, which is combined nor created a Council on Water- at any scale, whether at a project shed Management to encourage with significant funding from other level or watershed level, is most interagency collaboration and federal and state agencies, to successful when the objectives for the implementation a water- support the center’s research and managing risk are developed using shed-based floodplain manage- ongoing operations. the same standards, benchmarks, ment program. The resulting and quality data, and when California has utilized bonds, Louisiana Watershed Initiative solutions (or mitigation strategies) a partnership with the USACE, serves to coordinate floodplain can be compared in the context and state investment to support management and mitigation, of one another. Holistic or inte- its comprehensive regional and including outreach, data man- grated watershed management, statewide planning process, agement, policy development, as exemplified by the San Antonio as well as a floodplain map- technical assistance, and planning, River Authority’s basin-wide ping program. North Carolina across federal, state, and local efforts to develop watershed

Texans’ views for future flood planning Stakeholders strongly favor a watershed-scale planning process for coordinating and guiding local efforts related to short-term and long-term flood planning, mitigation, and response (70 percent of responses).

Stakeholders noted a watershed-scale flood planning process should include opportunities to

pro-actively identify and prioritize projects with the greatest ability to reduce flood risk; assess both upstream and downstream effects of projects to minimize adverse impacts and develop regionally based, multi-benefit solutions; develop consistent policies and guidelines for floodplain management within a watershed; and, evaluate the impact of future scenarios influenced by population growth and associated land use changes, plus variations in the frequency and duration of rainfall events. A stakeholder from the El Paso workshop described future flood planning as “an effective tool to protect the well-being and property of Texans.”

State Flood Assessment | Texas Water Development Board 27 master plans that also promote Further, the planning process must relevant for flood planning. Water flood risk management, offers an be adaptable—able to incorpo- supply planning, even across ba- opportunity to evaluate whether a rate changes in population, data, sins, has a degree of predictability specific objective or solution may models, project viability, and in terms of available sources and negatively impact flood risk for an policies (TWDB, 2016). Finally, target delivery location that typi- upstream or downstream com- consistent support of any planning cally does not exist when planning munity and to consider potential process is important to ensure that for flood events. impacts on water quality, erosion, plans are updated and implement- water supply, etc. Although the ed according to stakeholder needs Flood planning requires different TWDB does not conduct flood (Brody et al., 2009). benchmarks, corresponding to planning, beyond support of high water levels created by, for flood protection planning grants example, the 1 percent annual What about regional water chance flood event under present for communities, the TWDB does planning? require grant awardees to work at day or future build-out conditions. It is no surprise that the effective- the watershed-scale and engage Flood planning also requires ness of the statewide regional all stakeholders. Additionally, the different datasets and models for water supply planning process in TWDB adheres to Texas Water evaluating potential risk reduc- Texas leads some to draw paral- Code §§ 17.774 and 17.776, tion strategies. Groundwater and lels between it and any potential requiring a determination that surface water availability models statewide flood planning process. a requested project will have used in regional water planning However, there are critical, funda- no upstream or downstream are not applicable to evaluating mental differences in the purpose effect before awarding financial the distribution and timing of and goals of each effort. assistance. flood events. For reasons such as these, the water supply and flood Planning for water supply projects Sound planning is based on a planning processes are distinct; focuses on providing reliable number of core elements. First, hence, flood mitigation projects water supply throughout ex- effective planning is based on rarely appear in local water sup- tended periods of low rainfall. quality data, robust models, and ply and wastewater infrastructure Thus, planning for drought-of- sound science coupled with a project lists. record conditions, by definition, vetting process that is inclusive does not consider or attempt to of all interested parties (stake- Nonetheless, there may be bene- address flood risks. Flood risk holders). Second, appropriately fits for both processes to at least assessment and mitigation plan- scaled planning areas must be consider strategies that simulta- ning aims to achieve an entirely established. Stakeholders within neously address water supply and different purpose—reducing or these areas must be encouraged flood risk reduction (e.g., aquifer preventing loss of life and prop- to participate, to determine their storage and recovery or variable erty during high precipitation vision for the future, and to set reservoir flood pool capacity) or events—using a set of parame- goals according to an established to evaluate proposed strategies ters and technical analyses that timeline. Third, empowered by in the context of hydrological are distinct from those used in sound data and a common vi- extremes from drought to flood water supply planning. sion, stakeholders need to con- (e.g., the siting of water supply or wastewater infrastructure). Section sider acceptable levels of risk and Flood planning activities are best 7.3 includes more discussion on use standardized benchmark(s) conducted at the watershed or the possible synergies between and protocols to consistently basin-scale. Whereas the geo- water supply and flood mitigation. evaluate alternative strategies to graphic units for drought and reduce or eliminate risk within water supply planning are based the planning area. If prioritiza- in part on river basins, they also tion of strategies is a goal of the consider aquifer delineations, planning process, management water utility development patterns, outcomes must be quantifiable political subdivision boundaries, and use a common set of metrics. and other factors not necessarily

28 Texas Water Development Board | State Flood Assessment 6. Flood mitigation in Texas Flood mitigation, which is any activity undertaken to prevent Throughout the 20th century, the through funding made available or reduce the impacts of United States invested heavily to the TWDB from the Disaster flood events, is needed in flood control infrastructure in Contingency Account No. 453 and can be expensive. response to devastating floods ($6.8 million in the 2016–2017 Flood mitigation is along major rivers across the biennium) and then via funding primarily a local activity nation. Between 1901 and 1991, from the Floodplain Management that could benefit 51 major reservoirs were con- Account ($6.1 million) and gener- from greater state and structed in Texas for flood control al revenue ($1.7 million) during regional coordination. or with flood storage capacity the 2018–2019 biennium. The Estimated from (TWDB data). In addition, the TWDB anticipates current funding stakeholder input, an Natural Resources Conservation to continue and has requested an additional $18.0 to $26.6 billion is needed Service (NRCS) constructed ap- additional $4.45 million from the to complement existing proximately 2,000 smaller reser- 86th Texas Legislature to expand funding for flood voirs to also provide flood control the agency’s flood science efforts mitigation in Texas. throughout the state. Over time, to better prepare for and recover the national approach to address- from flood events. to regulatory requirements related ing reoccurring flood events and to environmental protection, their the hazards they pose to people, 6.1 Types of flood multi-jurisdictional nature, and property, and the economy has the project scale. Minor structur- evolved to encourage a wide- mitigation activities al activities provide local-scale range of locally driven solutions. Flood mitigation activities fit into stormwater management benefits Flood mitigation involves any one of two broad categories: via grey and green infrastructure, combination of actions taken structural or non-structural. Struc- such as culverts, gates, diversions, to prevent flooding, reduce the tural activities typically involve vegetation (including trees), and likelihood of catastrophic flood- placement of a new structure in detention and retention basins, ing, or lessen the impact of flood or near a river channel or along aimed at protecting critical facil- events—and represents a third the coastline to act as a physical ities (water supply infrastructure, pillar of comprehensive flood risk barrier to water. The removal of utilities, sanitary sewer systems, management. those same types of physical bar- roads, and bridges) and other properties by retaining or divert- In Texas, mitigation activities riers is also considered a struc- ing floodwater which accumulates have largely been implemented tural activity. All other activities during rain events. through funding from federal qualify as non-structural. In Texas, most communities employ some programs. With the exception of A wide array of flood mitigation combination of both (Figure 6.1). a long-standing commitment to activities is considered non-struc- funding Flood Protection Planning Structural approaches may be tural: educational efforts that grants, the state historically only further divided into major and increase public awareness, provided matching funds required minor activities. Major structur- professional training, or technical to support the administration of al activities, also termed flood assistance related to flooding; several FEMA programs focused risk management infrastructure, creation of local flood hazard on flood mitigation grants, include the construction of levees, mitigation plans; installation community assistance for the dikes, floodwalls, dams, and oth- of flood early warning systems; NFIP, and mapping assistance. er channel alterations to provide collection and analysis of geo- However, in recent years Texas larger-scale flood benefits. These graphic, hydrologic, and atmo- has greatly increased its support projects generally require more spheric data to identify flood risks for flood risk management—first time and effort to complete due or monitor conditions; restoration

State Flood Assessment | Texas Water Development Board 29 Figure 6.1. Examples of mitigation activities implemented by stakeholders. Rectangle size corresponds to frequency of survey responses.

Non-structural Structural

Flood insurance Floodplain development Local drainage Roadway bridges, (participation in the NFIP) ordinances improvements culverts, and pipes

Local channel conveyance improvements

Flood awareness Property training and/or buyouts or education relocations Levees, flood walls, Elevation, flood- Local detention Regional detention related proofing, and/or and/or retention and/or retention infra- reconstruction Flood warning system basins basins structure

and conservation of wetlands, governments may adopt amend- or discouraging it in flood-prone forests, and open space; and ed versions of these codes to fit areas (e.g., through high insur- completion of local feasibility, local needs. Zoning ordinances ance premiums or by designa- design, and engineering studies. are enacted at the local level to tions of a floodway or special regulate development and land- coastal zone). Floodproofing and Policy and regulation activities, use in flood-prone areas. property buyouts, including acqui- also considered non-structural, sitions and relocations, round out include setbacks, building codes, Participation in the NFIP is a the list of non-structural activities zoning ordinances, subdivision non-structural mitigation activity. to mitigate flood impacts. rules, and special purpose or- In fact, the NFIP requires struc- dinances. The state periodically tures to be built “reasonably safe Flood mitigation strategies con- adopts certain building codes from flooding” (44 CFR 60.3) sidered by communities across related to scientific and safety by either guiding development Texas represent a wide variety standards for residential and (e.g., elevating structures or of project types, from non-struc- industrial construction. Local anchoring manufactured homes) tural, lower cost strategies such

30 Texas Water Development Board | State Flood Assessment resources, both existing and un- available, that communities need Stakeholders’ Top 3: financial assistance to implement a variety of activities for flood mitigation to reduce flood risk. Stakeholders identified financial assistance for implementation of Analysis of the cost for project structural and non-structural flood mitigation projects as the number mitigation and the availability one area for the state to invest resources. of local funding for this section is derived exclusively from information provided by stakeholders as open land preservation and projects totaling $23 million). The through financial survey ques- implementation of building codes program also funded several oth- tions, which generally represent to large-scale, higher cost infra- er types of projects ranging from a 10-year planning horizon. structure projects such as reser- early warning systems (34 projects As such, the financial analysis voirs and drainage improvements. totaling $4.7 million) and public does not include long-term cost Between 1996 and 2016, FEMA’s awareness (23 projects totaling or funding need projections for Hazard Mitigation Assistance $6.4 million) to technical assis- the state, does not yield a list of grant program invested $1.4 tance at $438,000, among other ready-to-implement flood miti- billion in support of 753 mitiga- activities (Economist Intelligence gation strategies, and involves tion projects in Texas (Economist Unit, 2018). This represents only estimates with certain limitations Intelligence Unit, 2018). This some of the activities that have (discussed in Chapter 8). How- program includes post-disaster been carried out in Texas. ever, the analysis provides insight funding for Hazard Mitigation into the overall anticipated costs Grants, Pre-Disaster Mitigation 6.2 Cost of for mitigating flood risks and (both administered by TDEM) the statewide funding shortfall, and pre-disaster Flood Mitigation mitigation which prevents the implementa- Assistance grants (administered Flood mitigation is sometimes tion of strategies. We did this by by the TWDB). Projects includ- necessary and often expensive. accounting for the availability of ed buyouts and elevation of The details and nuances related local funds and non-local (state structures (186 projects totaling to implementation also may be and federal) financial programs. $655.4 million), critical infra- as complex as the funding mech- For details of the methodology, structure and flood control (109 anisms that make implemen- see Appendix A, posted online at projects totaling $455 million), tation possible. For this report, www.TexasFloodAssessment.com. and mitigation planning (163 the TWDB assessed the financial

Estimating financial need for flood mitigation Financial information to estimate costs for flood mitigation activities comes from two sources:

(1) Reported estimates of mitigation costs and available funding based on survey responses representing 60 percent of the state’s population, and

(2) A statistical analysis developed to estimate costs and available funding for the remaining 40 percent of the population not represented by survey responses.

More details are available in Appendix A at www.TexasFloodAssessment.com, but the basic methodology is as follows:

Flood Funding Shortfall = Anticipated Costs – Available Local Funds – Available Non-Local Funds

State Flood Assessment | Texas Water Development Board 31 6.2.1 Anticipated the communities not represented for very large federal projects or mitigation costs by survey responses (the non-re- costs identified by the state for sponding communities). rehabilitating high hazard dams, Anticipated statewide estimates that combined would The TWDB compared this esti- mitigation costs, $31.5 add another $14 billion to the mate of anticipated mitigation to $36.0 billion state’s mitigation needs. We also costs for Texas to the flood fund- recognize that the methods used Based on the mitigation needs ing needs identified by California in this assessment, as well as the reported by survey respondents, and found figures to be com- mitigation activities needed to the estimated total statewide cost parable. California has a stated reduce flood risks, differ between for future flood mitigation ranges need of $32 to $52 billion to California and Texas. between $31.5 and $36.0 billion implement projects identified in its (Table 6.1). This range comes current planning cycle, including from the amount reported by $6 billion in flood management 6.2.2 Available communities that responded to projects recommended by the mitigation funding the survey, totaling about $23.4 USACE (CDWR, 2013). Because billion, combined with a range the methods of this assessment Locally available funding, of $8.1 billion to $12.6 billion are based solely on responses $7.1 to $8.2 billion as estimated from a statistical from the two stakeholder surveys, The amount of local funding analysis to capture the costs as- we did not factor in cost estimates communities may have available sociated with mitigation needs for to contribute to flood mitigation activities ranges from $7.1 to $8.2 billion. We base this esti- Cost of recovery versus mitigation mate on information provided by respondents, as well as the Since the focus of this assessment is mitigation of future flood statistical estimates of available events, the TWDB has not considered costs related to disaster funding for the non-responding recovery. Given the extent of devastation from Hurricane Harvey in communities. Specifically, survey 2017, the costs of recovery from this event alone are staggering. respondents in cities and coun- In October 2017, Governor Abbott’s Rebuild Texas Commission ties reported having about $4.8 requested $61 billion in federal appropriations above current billion in local funds to implement federal expenditures for rebuilding public infrastructure damaged or flood mitigation activities, based destroyed by Hurricane Harvey and for projects designed to mitigate on their historical and anticipated the impact of future storms on the Texas Gulf Coast. Congress re- availability of local funds. sponded to this request with a significant amount of federal funding in the Bipartisan Budget Act of 2018, which included $90 billion in Available non-local funding, disaster aid for Texas, Florida, and Puerto Rico. Thus far, Texas has $2.3 to $5.3 billion received significant funding for Harvey recovery activities, including: We estimate the total funding The U.S. Army Corps of Engineers Civil Works Long-Term available from existing state Disaster Recovery Investment Program received $4.9 billion for and federal financial assistance five ongoing construction projects and five new-start construc- programs to range from a low of tion projects in Texas, along with $15.1 million for five studies. $2.3 billion to as much as $5.3 As administered by the Texas Department of Public Safety, FEMA billion over a 10-year period. will provide an estimated $1 billion for hazard and flood mitigation Of the potential $5.3 billion of projects through the Hazard Mitigation Grant Program. assistance available, approximately $2.3 billion is estimated to The Texas General Land Office is administering $5.024 billion be in the form of grants, generally in Community Development Block Grant–Disaster Recovery requiring some degree of local funds provided through the Department of Housing and Urban cost-share. The remaining $3.0 Development for Hurricane Harvey recovery. billion is in the form of loans

32 Texas Water Development Board | State Flood Assessment Stakeholders need to implement a variety of mitigation activities Stakeholders indicated that the majority of funds spent in the last 10 years went to local drainage infrastructure. Roadway crossings, regional detention or retention basins, and property buyouts also represent a large component of local spending.

Looking ahead, stakeholders indicated a need for more funding to support implementation of local drainage improvements, local and regional detention and retention basins, improvements to bridges/culverts/pipes and channel conveyance, as well as non-structural solutions such as buyouts, warning systems, and educational programs. from the TWDB with interest rates on behalf of local, state, and either considerably below market federal programs. Limitations of levels or reflecting the state’s low the existing programs considered Stakeholder cost of funds. for this analysis are discussed in preferences for Section 6.3, Funding sources; a Given that flood mitigation summary of these programs and types of non- projects do not generate reve- the range of funding availability local funding nue, repayment of these loans is provided in Appendix A at likely would require local fees Survey respondents describe www.TexasFloodAssessment.com. or ad valorem taxes. Estimating needing anywhere from 0 to the available funding for existing 100 percent of project costs financial programs is difficult, 6.2.3 Mitigation covered by outside financial due in part to the fact that some funding shortfall assistance. Small communities federal funds are available only and regions that are primarily following a presidentially de- Statewide flood funding rural indicated the highest clared disaster. These estimates shortfall, $18.0 to $26.6 need for non-local funding. are further complicated as we billion must assume continued availabil- When asked what types of fi- ity at the current and historical After determining the statewide nancial assistance stakehold- rates of funding; speculate on the anticipated cost for mitigation ers might pursue, the most timing and allocation of federal and factoring in both local and preferred choices were either appropriations; and anticipate non-local funds that are poten- a 90/10 cost-share program policy and funding choices made tially available to offset this cost, (90 percent non-local contribution/10 percent local match) or a 75/25 cost-share program. Less popular but Table 6.1 Summary of statewide flood funding needs (in $billions), estimated of equal interest to about 20 using information on anticipated mitigation costs and local funding availability as provided by stakeholders via financial survey questions and information on percent of respondents are available non-local funding from existing state and federal financial programs. programs with either a 50/50 cost-share or a zero percent Range (in $billions) interest loan. Few stakeholders opted for assistance via Anticipated mitigation costs $31.5 – $36.0 market rate loans, subsidized Available local funds $7.1 – $8.2 loans, or state participation in projects. Nearly 40 percent Available non-local funds $2.3 – $5.3 of respondents did not know Statewide flood funding shortfall $18.0 – $26.6 what mechanism to choose.

State Flood Assessment | Texas Water Development Board 33 the TWDB estimates the statewide 6.3.1 Local funding Stormwater utility fees: flood funding shortfall ranges Over the past several decades, Stakeholders identified the top the stormwater utility model from approximately $18.0 to three sources of local funding has increasingly been used as $26.6 billion. The lower value used in their communities to be a tool to raise local funding for of $18.0 billion accounts for general funds, stormwater utility stormwater management both in access to the highest amount of fees, and bonds (Figure 6.2). Texas and the country. Creation available local and non-local Below we describe the most com- of a stormwater utility allows a funding, while the upper value of mon local revenue sources used municipality to have a dedicated $26.6 billion accounts for access for flood management activities. to the least amount of available revenue stream for stormwater local and non-local funding. General fund: General fund management that is directly revenue is largely from property, based on how much a property sales, and other taxes, which contributes to stormwater runoff. 6.3 Funding sources provides a substantial amount Survey respondents reported this is the second highest source of Communities across the state use of money. Though this is the pri- funding for flood management a variety of funding sources, from mary source of funds, as reported activities in their community. local funding to state and federal by stakeholders, often it is not An annual survey conducted financial assistance to implement enough to adequately cover flood by Western Kentucky University flood risk mapping and flood mit- management activities in addition to all other municipal programs. identified more than 1,600 igation, planning, and protection Special tax districts are sometimes stormwater utilities in the country activities. However, the types and used to tax only the portion of the and at least 114 in Texas. Of the availability of funding vary widely. population that will benefit from 40 cities in Texas with populations Though not exhaustive, this sec- a specific project. Our survey, greater than 100,000, 31 have tion describes common financial however, indicates that only a a stormwater utility. The statewide programs and sources of funding few communities in Texas have average stormwater fee is $4.28 available to communities. implemented such tax districts for per month (Campbell, 2018; U.S. flood mitigation. Census Bureau, 2018).

Figure 6.2 Sources of local funding used to support flood management activities as identified by survey responses (percent of respondents). In addition, 24 percent or respondents stated they had no local funding source dedicated to such activities. 50

15 Percent of respondents Percent 10

0 General Stormwater Bond Ad valorem Permitting Special tax Impact fund utility fee program tax fee district fee

34 Texas Water Development Board | State Flood Assessment Facts about local funding for flood management activities 24 percent of respondents said their community does not fund flood management activities Modeling and with local funding. mapping Rural communities are the most 9% likely to not have local funding for these activities. Early warning systems 17 percent did not know 5% if their community uses local funding for such activities. On a per capita ba- Operation and sis, large cities spend maintenance more than twice as 49% much as small cities on flood mitigation activities. Infrastructure 31%

Displayed to the right are expense categories for communities with budgets allocated to flood management activities.

Public awareness 6%

Bonds: Survey respondents select- fees. Impact fees are sometimes presented as federal programs. ed bonds as the third most often assessed as a one-time payment Estimates for available state and used funding source. Communities for new developments to offset federal funding for mitigation typically use either stormwater rev- their anticipated impact to the projects in Texas range widely, enue bonds or general obligation community. Another program is a from about $2.3 billion to just bonds for this type of funding. fee-in-lieu in which developers pay over $5.3 billion, and involve Bonds can fund various activities, a fee to the community rather than inherent uncertainty, as described such as home buyouts, upgraded building a site-specific stormwater in Section 6.2.2, Available miti- early warning systems, and infra- mitigation project in their devel- gation funding. These resources structure repairs. opment. are geared toward planning for and implementing mitigation Ad valorem taxes and other activities, and few provide oppor- fees: Though less frequently a 6.3.2 State and tunities to fund mapping efforts source of funding, some survey federal funding or planning beyond the project respondents report using im- Financial assistance programs level. Appendix A, available at pact fees, permitting fees, or ad are categorized as state or www.TexasFloodAssessment.com, valorem taxes, respectively, to federal based on the original contains a summary of existing fund activities. For example, com- source of funds. Many federal programs with the associated pro- munities can fund their floodplain programs are administered at the jected available funding. A num- management program through state level and may have a state ber of these financial assistance floodplain development permitting contribution, but herein they are options, however, are not fully

State Flood Assessment | Texas Water Development Board 35 utilized. Hence, we briefly discuss is frequently oversubscribed, Federal programs some of the factors limiting access meaning that there is more Federal programs related to to and use of the relevant programs. demand than available funding. flood mitigation and mapping In 2016, the TWDB received 41 typically offer much greater fi- State programs applications requesting funding of nancial assistance than is avail- State programs generally have $7.26 million, though there was able at the local or state level, fewer requirements than federal only $3.5 million in grant assis- but the funding often has many programs. However, state pro- tance available. In 2018, 38 ap- limitations. Funding is typically grams that can finance flood miti- plications requesting $5.6 million restricted to post-disaster proj- gation generally only offer smaller in assistance were submitted, but ects located in federally declared amounts of grant funding or no only $1.8 million was available. disaster areas. For programs substantial reduction in the interest The Texas Water Development and projects not tied to disaster, rate on loans. This results in a high Fund (DFund), also administered Texas competes with other states demand for grant programs and a by the TWDB, has funding avail- such as for Cooperating Techni- low demand for loan programs to able through the agency’s existing cal Partners funding for mapping finance flood mitigation activities. $6 billion evergreen general activities. In some cases, flood-re- Workshop participants under- obligation bonding authority. lated projects also compete with scored this point by noting that But since the program offers a other types of projects. Federal more state financial resources with subsidy only in the form of a funding through the Clean Water substantial subsidies would serve credit benefit, which may not be State Revolving Fund (CWSRF), to benefit implementation of flood of value to many higher rated administered by the TWDB, can mitigation projects. borrowers, it is typically not an at- fund flood-related (pre-disaster) mitigation projects, but applicants The TWDB’s Flood Protection tractive option for flood mitigation projects. DFund has funded only must compete with wastewater Grants program, for example, and water supply projects. How- funds detailed studies of flood- two flood-related projects within the last 10 years. ever, following Hurricane Harvey, plains, among other activities. the TWDB set aside funds in the The program, funded via the The State Water Implementation CWSRF, as well as in the Drinking Floodplain Management Account, Fund for Texas (SWIFT) pro- Water State Revolving Fund, to gram1, the state’s most prominent provide post-disaster funding op- financial assistance program tions to communities for projects Funding provided for water projects, is designed related to water supply, wastewa- for and restricted to addressing ter, or stormwater management by the Floodplain water supply strategies. Though facilities for disaster recovery and Management some synergies with flood mitiga- other urgent need situations. Account tion may exist (see Section 7.3, Synergies with existing programs), Federal programs also have In each state fiscal year, state water plan projects typically complicated and extensive appli- the first $3.05 million of do not include components that cation and reporting requirements, maintenance taxes imposed address flood mitigation, and coupled with a high degree of on authorized insurers and no flood-related projects have uncertainty in both the timing and deposited into the general been funded through the SWIFT distribution of funds. These factors revenue fund are reallocated program to date. Furthermore, make applying for funding and to the Floodplain Manage- opportunities for loan forgiveness complying with associated requirement Account, administered or grants under this program are ments challenging for commu- by the TWDB (Texas Insur- expressly prohibited in statute nities, particularly for those that ance Code § 251.004). This (Texas Water Code § 15.435). cannot support staff or contractors funding supports grants, data dedicated to these tasks. collection, stream gaging, 1 The SWIFT program includes two funds, the State Water Implementation Fund for Texas and outreach efforts. (SWIFT) and the State Water Implementation Revenue Fund for Texas (SWIRFT). Revenue bonds for the program are issued through SWIRFT.

36 Texas Water Development Board | State Flood Assessment 7. Roles and other considerations

Floodplain management encompasses a broad spectrum Responsibilities for floodplain management and mitigation lie with local decision makers. of challenging issues and, as is true of any interdisciplinary A diverse group of local, state, and federal entities play a topic, requires a diverse group role in the collective effort to mitigate flooding. of individuals working collabo- Stakeholders cite lack of financial assistance as the biggest ratively toward a common goal. barrier to undertaking floodplain management activities Whether before, during, or after at the local level. a flood event, a complex web of local, state, and federal entities community must designate a assess the adequacy of local contributes resources—time, staff, floodplain administrator (often structural and non-structural data, funding—in an effort to called a floodplain manager) who mitigation activities. address flooding impacts to lives must understand, interpret, and In reality, however, a diverse and property. This chapter sum- explain local floodplain manage- marizes those entities with respon- group of local communities, ment regulations and review them regional groups, and state and sibility for mitigation in Texas and for compliance. Specific to flood- discusses barriers to floodplain federal entities plays a role in the plain management (Texas Water collective effort to reduce flood management, as well as potential Code § 16.315), communities in synergies with water supply. impacts. In Texas, federal, state, Texas also may and regional entities have some apply for grants and financing flood-related role—in addition 7.1 Responsibilities to support mitigation activities, to the local communities on for flood mitigation the frontline (Table 7.1). Over- collect reasonable fees to lapping jurisdictions based on The responsibility of preparing for cover the cost of administer- political rather than watershed and mitigating flooding in Texas ing floodplain management boundaries and differing mis- lies with local decision makers. activities, sions among the various entities Texas Water Code § 16.315 lists use regional or watershed create a multi-layered, complex actions that political subdivisions approaches to improve flood- environment, which sometimes of the state of Texas are autho- plain management, and leads to unclear responsibilities rized to take related to the NFIP. and uncoordinated efforts. For example, each participating cooperate with the state to

State Flood Assessment | Texas Water Development Board 37 Table 7.1 Select entities with flood-related responsibilities. (Special purpose districts include river authorities, soil and water conservation districts, water control and improvement districts, flood control and improvement districts, municipal utility districts, and levee improvement districts.) The Texas Water Development Board also represents the responsibilities related to the Texas Natural Resources Information System.

management management Stream gaging (State and Local) Weather forecasting Weather Stormwater and drainage Flood inundation mapping Hazard mitigation planning Dam/reservoir ownership and Flood insurance rate mapping Emergency operations planning National Flood Insurance Program National Flood Insurance Program floodplain regulation enforcement Levee ownership and management

City governments P S S P P P P P P

County governments P S S P P P P P P

Local Special purpose districts P S S P P S P P P

Councils of government S S S P S S

Texas Commission on Environmental Quality S S S S S

Texas Department of Transportation S S S P

Texas Division of Emergency Management P P P

State Texas General Land Office S S

Texas State Soil & Water Conservation Board S S S

Texas Water Development Board P S P S S S

Federal Emergency Management Agency P P S S S

National Weather Service P P S P S S

U.S. Army Corps of Engineers S S P S S P P P Federal Natural Resources Conservation Service S S S

U.S. Geological Survey P S P S

P = Primary role; in charge or takes the lead = Entities take on responsibility S = Secondary role; provides data or technical support = Some, but not all, entities take on responsibility or has regulatory responsibility

Stakeholders call for increased collaboration and coordination Stakeholders called for increased collaboration and coordination between jurisdictions responsible for flood mitigation. Sixty percent of respondents noted that they work with other entities in their region to address flood risk; an additional 17 percent believe they would benefit from coordinated efforts.

38 Texas Water Development Board | State Flood Assessment State agencies serve as interme- The TWDB also has authority to dams in Texas, including 2,000 diaries between local and federal evaluate floodplain manage- built by the NRCS. Approximately partners, facilitating cooperation, ment activities and flood control 60 percent of the non-federal administering federal programs programs within the state; to dams are privately owned and and grant dollars to local com- study the adequacy of existing maintained. munities, and offering technical public and private measures, assistance for certain floodplain laws, regulations, and ordinances Per Texas Water Code, Chapter management activities. The TWDB in flood-prone areas; to evaluate 57, local levee improvement dis- houses the State Coordinator’s available engineering, hydro- tricts may construct and maintain Office for the NFIP in Texas; is re- logic, and geologic data; and levees near rivers, creeks, and sponsible for aiding, advising, and to conduct and make available streams; provide for drainage and coordinating the efforts of local floodplain studies and mapping improvements to lands reclaimed communities wishing to participate (Texas Water Code § 16.316). from overflows; and straighten or in the program; and is responsible These authorities are consistent improve rivers to control water. for administering the following with the agency’s Flood Protec- Municipal utility districts also have FEMA programs (44 CFR § 60.25; tion Grants program and with similar authority for the control Texas Water Code § 16.316): more recent initiatives supported and drainage management of by funding from the Office of the excess floodwater (Texas Water Community Assistance Governor and the Floodplain Code, Chapter 54). The TCEQ is Program-State Support Management Account to enhance authorized to inspect levees under Services Element pro- flood notification systems and construction, but there is currently vides technical assistance, support floodplain management no state funding or staff dedicat- floodplain management planning. Requests from stake- ed to a levee safety/inspection education, assistance meeting holders to have access to more program. An effort underway by NFIP compliance require- technical support and updated the USACE seeks to develop a ments, and post-disaster flood hazard mapping align with complete inventory of levees as assistance—all to encourage these capacities. the first step toward certification floodplain management of levees constructed to provide expertise and capability in Certain types of mitigation flood protection. Texas communities. activities, such as the construction and ongoing maintenance Stormwater and drainage-related Cooperating Technical of dams and levees, dictate mitigation activities are carried Partners Program specific responsibilities. Texas out individually or collabora- enhances collaboration has 37 federal dams owned tively by local entities such as between communities, FEMA, by either the USACE, the Inter- cities, counties, river authorities, and other local partners in national Boundary and Water municipal utility districts, drain- efforts toward creating or Commission, or the U.S. Bureau age districts, stormwater control updating their FIRMs. of Reclamation. districts, and flood control districts across the state. The U.S. Envi- Flood Mitigation Assis- Non-federal dams are owned and ronmental Protection Agency’s tance Grant Program pro- maintained by the state, counties, Municipal Separate Storm Sewer vides planning grants to com- cities, water districts (including System (MS4) regulations require munities to develop or update soil and water conservation certain owners or operators of the flood hazard component districts or water control and im- municipal separate storm sewer of a jurisdiction’s Multi-Hazard provement districts), river authori- systems to acquire permits to Mitigation Plan and project ties, private organizations, or indi- discharge stormwater into sur- grants for mitigation through viduals. The Texas Commission face waters of the state. Though localized flood risk reduction on Environmental Quality (TCEQ) primarily related to water quality, projects or the acquisition (buy- sets regulatory safety standards certain flood protection benefits out), relocation, floodproofing, for and is charged with inspection do exist. Presently, Texas does or elevation of structures insured of more than 7,000 non-federal not have statewide standards to under the NFIP.

State Flood Assessment | Texas Water Development Board 39 guide mitigation of local drainage or prevent flooding; to slow water than one in four respondents); issues; thus, adopted criteria for quality decline; and to avoid loss whereas, county-level and small local drainage standards vary of opportunity that is a result of communities reported having across communities, even within rapid growth” (NCTCOG, 2017). substantially less access. the same watershed. Confusing funding options. In a few cases, communities 7.2 Barriers to Public awareness of the range are moving toward an inte- implementation of funding programs is limited. grative approach that factors Currently five state agencies in hydrology, hydraulics, water Stakeholders reported that and five federal agencies share quality, and open land areas at financial assistance is the most responsibilities for administering the watershed scale to collectively essential resource needed by 16 funding programs. Commu- address drainage issues. The their communities to implement nities seeking financial assistance North Central Texas Council of floodplain mapping, mitigation, must self-navigate through these Governments developed a volun- and management activities. Next disparate options to determine tary, 16-county watershed man- to this, the biggest barriers com- which program best addresses agement initiative with “a goal munities face include navigating their specific needs, minimizes to allow for sound development available funding options and strain on local resources, facil- through regional consistency; to associated application processes itates project implementation, recognize cost savings associated and protecting communities while and ultimately provides the best with the investment in effective waiting through the drawn-out overall value. Further, eligibility watershed management to reduce timelines for receiving funds or criteria differ among the various completing projects. If left unre- programs, which split funding into solved, these barriers can prevent multiple categories—each with Stakeholders cited a range of communities from successfully their own qualifications, sched- limitations preventing com- implementing floodplain man- ules, and application process. munities from identifying risks agement activities, even if new or solutions. Listed in order of funding becomes available. Complicated application relative importance, they are processes. Stakeholders com- Local share funds. The local municated that the process of ap- a lack of financial re- share requirement for state and plying for and obtaining federal sources to conduct stud- federal financial assistance creates assistance is prolonged, compli- ies, update flood maps, a deterrent for communities that do cated, and confusing. Stakehold- hire staff, and develop not have access to a local funding ers also expressed a desire for a expert local knowledge source. Survey respondents simplified, faster funding appli- for proper floodplain indicated needing non-local cation process, which may be management and deci- (outside) funding to cover up to easier to achieve for state finan- sion making; 100 percent of total cost for flood cial assistance programs. Small mitigation activities, including the prolonged timeframe communities often cannot afford structural projects, mapping, early a dedicated floodplain adminis- and complex process for warning, and public awareness implementing projects; trator position and therefore may activities. Only one in five lack the staff resources to submit a lack of public interest, floodplain administrators stated grant applications. As a result, 42 competing local priorities, that their community has a percent of stakeholders requested lack of coordination and revenue stream to accumulate that the state provide additional cooperation within a local funds for the local share technical training and guidance area, lack of community requirements of grant programs in navigating the complex dead- leadership to implement or to repay loans provided by lines, requirements, and paper- projects; and, the state. Responses from urban work associated with both state a lack of broad authority areas and larger cities reported and federal funding programs. to enforce regulations. having slightly better access to Currently, both TDEM and the a local revenue stream (greater

40 Texas Water Development Board | State Flood Assessment TWDB offer technical assistance contracting out for these services. more streamlined processes and as part of their administration of increased transparency. FEMA grant funding, and FEMA Lack of training. No state-level provides online and in-person requirement exists for training or Patience is key to implementing trainings related specifically to certifying floodplain administrators a federally funded project. The grants administration. or others with flood-related re- application review and approv- sponsibilities. However, more than al process can take up to one 2,000 Texans are professionally year. Once approved, project Stakeholders identified certified floodplain managers implementation may be further education, training, and (CFMs) through the Texas chapter delayed for a variety of reasons, technical assistance as of the Association of State Flood- including weather conditions or a top priority for state plain Managers, known at the even unanticipated changes in level action. Their responses Texas Floodplain Management funding allocations. For struc- characterize a wide gap made Association. Accessibility to pro- tural activities, projects may up of a lack of financial re- fessional development appears require extensive permits for sources and access to training, to be easier and more affordable environmental protection, histor- which contributes to an ongo- for floodplain administrators in ic preservation, and related land ing lack of basic knowledge more populated or urban areas. use development. If a community of floodplain management Respondents from small commu- does not have sufficient in-house principles, a misunderstand- nities report difficulty in attending staff to navigate these disparate ing of flood risk, and difficulty classes because of a lack in staff permitting requirements, it may successfully applying for and availability, travel funding, or be forced to hire an outside managing grants. related resource constraints. In consultant and that procurement general, stakeholders requested process can add months to an Lack of staffing. Stakeholders increased availability of low-cost already lengthy process. expressed that insufficient staffing or free training. Stakeholders also at all levels of government slows suggested including floodplain State-funded programs typically down the flood mitigation pro- management topics as part of the have fewer requirements. For ex- routine training required of state cess. Chokepoints exist at every ample, Flood Protection Grants and local officials with job duties step of project timelines, which administered by the TWDB have related to emergency manage- can exacerbate this issue. While a relatively fast path to funding. ment within their first 180 days administratively burdensome for Aside from requiring assuranc- in office (per Texas Government FEMA and state agencies, comes that the principal applicant Code, Chapter 418). munities bear the greatest burden has the authority to plan and implement projects and that as the lack of adequate and time- Prolonged timelines. Project the proposed project does not ly mitigation can have real-world timelines for flood mitigation grant duplicate existing projects, these consequences. Understaffing— programs can take anywhere from state funds do not require fed- and its consequences—becomes months to years from the start eral coordination nor approval especially acute during disaster of an application to the start of (beyond existing requirements events when resources are divert- construction or project implemen- such as those related to wetlands ed to emergency response. Spe- tation (if non-structural). A range permitting). However, these funds cific types of stakeholder requests, of factors, particularly the source are limited and are only offered beyond the above-mentioned of funding and required amount of once a biennium. need for assistance in navigating documentation and authorization, financial programs and applica- determines the length of these Similarly, the federal timeline tion processes, included the need timelines. The more complex the for creating or updating FIRMs for access to state engineers and processes, the lengthier the appli- through the FEMA adoption surveyors to provide project-spe- cation review and disbursement process requires years of par- cific technical guidance and period. Stakeholders expressed ticipation and patience by com- planning assistance. Small com- frustration with this aspect of munities. But as observed in this munities prefer this option over project implementation, requesting assessment, opportunities exist for

State Flood Assessment | Texas Water Development Board 41 aggravating downstream flooding in the case of prereleases from storage. Whether undertaken during project design or post- construction, balancing flood protection and water supply objectives for big projects requires careful study of the physiographic setting of the project. Even for large projects, improvements in secondary objectives while meeting primary objectives can be modest. For example, reallocation of flood storage within Lake Texoma added only 103,003 acre-feet per year to water supplies— less than 3 percent of the total Tom Miller Dam, near Austin, opens the flood gates during flooding in 2018. volume of the reservoir (Brougher and Carter, 2012). the state to enhance flood hazard provide communities with reliable At the other end of the spatial mapping for the benefit of floodwater supplies, which often scale, small actions, such as plain management, mitigation, requires storing water during adoption of low-impact devel- and emergency response. times of plenty for later use. opment practices, can reduce Despite these two distinct goals, excess runoff during storm events, projects that can meet both flood and when stored may increase 7.3 Synergies with protection and water supply water supplies or reduce wa- water supply objectives range the spectrum ter demands later. Examples of Despite recent interest in manag- from very large, such as reservoirs low-impact development practices ing floodwaters to augment water or aquifer storage and recovery include rooftop rainwater capture, supplies, particularly in water facilities, to relatively small, such v-cuts in curbs to allow storm- scarce areas, it is not easy to as low-impact development water to drain to landscaped achieve such synergies. The type practices. For large projects, areas, and permeable pavements and scope of activities involved in such as water supply reservoirs, that allow infiltration to aquifers. planning for floods can vary sig- it may be difficult or impossible Though individual projects may nificantly from those designed for to repurpose their use, thus be small, cumulative effects can drought preparedness. Droughts limiting the potential for beneficial be significant. Garrison and may begin slowly and develop synergies with flood control post- others (2014) estimated such over an extended time period; construction. Once residential green infrastructure projects could whereas, floods are sudden, areas develop around a reservoir, provide an additional 420,000 sometimes violent, events. De- it may be impossible to expand to 630,000 acre-feet per year spite this, opportunities may exist flood storage capacity. Likewise, to water supplies in the state of to simultaneously increase flood considerations for changing California. The Texas Section protection for communities while reservoir operations to allow for of the American Society of Civil providing additional water supply. seasonally adjustable flood and Engineers recommends consider- conservation pool elevations ing these types of practices and During times of flooding, the goal are complex and require related alternative flood mitiga- is to safely retain or divert excess extensive study by operators to tion strategies in their recently water away from communities. weigh potential risks of either released report on flood risk During drought, the goal is to diminishing water supply or (TexASCE, 2018).

42 Texas Water Development Board | State Flood Assessment 8. Preliminary findings and stakeholder priorities

For this statewide flood as- among stakeholders from every Texas stakeholders most sessment, the TWDB surveyed corner of the state, but risk of strongly recommended floodplain administrators and this type of flooding is not dis- that the state many other stakeholders to better played on FIRMs. The statewide provide funding for understand local flooding issues, risk from stormwater flooding flood mitigation strategies for mitigating flood remains undetermined. activities, risk, and the financial resources Varying mitigation improve flood risk allocated at all levels of govern- needs: Communities across mapping, ment toward the common goal the state experience different encourage of protecting lives and property. types of flooding that require watershed-based Through online surveys, work- different mitigation strate- flood planning, and shops, and related meetings, we gies. Communities also are expand education also asked for input on the future in different stages of need or outreach and of flood planning. The preliminary preparedness—some have technical assistance. findings and stakeholder priorities completed local mapping Failure to act continues to provided herein reflect the senti- and planning efforts to inform expose Texans to signifi- ments of the majority of the more their mitigation needs while cant levels of flood risk. than 1,000 Texans who contributed others reported struggling their time to this effort. with how to get started. Stakeholder feedback reveals Need for collabora- that communities experience 8.1 Preliminary tion and coordinated financial limitations in hiring and training local floodplain findings planning: A web of inde- pendent federal, state, and administrators; need greater Stakeholder feedback and infor- local agencies and jurisdic- access to technical experts mation gathered throughout the tions are involved in flood- with knowledge of finan- development of this report suggest plain management. Coordi- cial programs, application broad consensus around a num- nation and collaboration are processes, and science and ber of key points. needed to avoid redundan- engineering; and desire better cies, simplify administrative understanding of flood risk Flooding is a fact of life and floodplain management in Texas: Texas experiences processes, and increase the effectiveness of ongoing and principles among state and some of the most severe local officials. flooding impacts in the U.S., future flood mitigation efforts. yet critical data sets and pub- Fiscal concerns: Two lic awareness are lacking. common impediments to 8.2 Limitations and Outdated maps: Smaller more effective flood planning uncertainties in communities tend to either and project implementation estimating costs have outdated flood hazard are meeting local cost-share requirements and lack of a Limitation 1: Texas has maps or no maps at all, and no central repository of they often lack the data and consistent revenue stream to pay off loans. planned or implemented models needed to create or flood mitigation projects or update the maps for use in Lack of access to trained activities. Without an existing floodplain management, plan- professionals: Flood- statewide catalog, this assessment ning, and emergency response. plain management and relied primarily upon two stake- Local drainage issues: understanding of flood risk holder surveys. Medium and large Stormwater flooding was in Texas are hindered by a cities and special districts created identified as a top concern lack of training at all levels. for flood management purposes

State Flood Assessment | Texas Water Development Board 43 typically have robust plans to of the state is in need of mapping statistical confidence intervals and address local and regional flood (whether based on age of FIRM, to convey the uncertainty in both and drainage issues. Cost data unmapped stream miles, or wa- the source data and statewide collected from these entities is tershed-scale studies), it is difficult totals as extrapolated. Limita- considered reasonably reliable. to estimate mapping costs. tions from survey results were Smaller communities, in contrast, addressed with quality assurance typically lack plans and do not Limitation 4: Lack of a stan- and control measures, including have the resources required to dard benchmark for flood follow-up calls to verify responses produce them. Cost estimates for planning and mitigation. and a statistical analysis of survey mitigation activities in these com- Flooding is generally regarded results to qualify confidence in munities are considered less reli- as an event that causes property statewide estimates. These unable because they may not have damage or loss of life, but com- certainties must be kept in mind been associated with detailed munities experience different types when considering the cost estimates planning or feasibility studies. of flooding that require different presented in this assessment. mitigation strategies. Yet, there is Limitation 2: Sole reliance no standard to which all commu- on voluntary survey re- nities in Texas base their man- 8.3 Stakeholder sponses weakens the source agement efforts, which represents priorities data for estimating finan- another difficulty in estimating cial needs. Voluntary surveys costs. Unlike regional water Outreach across the state in tend to oversample the people planning groups, which develop March and April of 2018 pro- who feel strongly about a subject water management strategies to vided valuable qualitative and and under-sample the people meet future needs during a repeat quantitative data on the status who have less interest or opportu- of the drought-of-record (the of flood risk, floodplain man- nity to respond. While our surveys benchmark) and use a standard- agement, and flood mitigation have good geographic coverage ized cost analysis methodology in Texas. After reviewing all and represent needs for over half to ensure consistency, mitigation responses, the following stake- the state’s population, not every costs provided by stakeholders for holder priorities emerged. These community was willing or able to this assessment may be over- or priorities reflect input received participate. In total, Survey 1 gath- under-estimated depending on a from stakeholders, not necessarily ered responses from 34 percent of community’s circumstances. the opinions of the TWDB. communities in the state. Survey Limitation 5: Lack of frame- 1 - Provide financial assis- 2 captured only a small subset of tance for flood mitigation: those responding to the first survey, work for statewide planning. Texas has never undertaken Stakeholders resoundingly iden- and thus represents 11 percent of tified access to more financial communities in the state. statewide planning for flood, and myriad options exist for how to do assistance as the most important Limitation 3: Lack of com- so. Additionally, the timeframe for factor to meeting flood hazard prehensive, up-to-date developing a planning process mitigation goals. Access is limit- maps and information to has yet to be determined. The high ed primarily by (1) the availability aid communities in their level of uncertainty surrounding of non-local funds, (2) the diffi- planning efforts. Without future flood planning efforts—from culties associated with securing adequate maps, models, data, timeframe, to scale, to structure— those funds, and (3) the limited and information, communities and lack of precedent in this realm ability to generate local revenue struggle to address flood issues. make estimating costs for any to meet grant match require- Without planning efforts and planning effort imprecise. ments and support flood mitiga- identified solutions, many com- tion activities. As noted herein, munities are unable to accurately In our analysis, the TWDB took statewide flood mitigation costs estimate flood mitigation funding a variety of steps to minimize the over the next 10 years are an- needs. Without a thorough un- impact of these limitations. We ticipated to be more than $31.5 derstanding of exactly how much present financial estimates for billion. Due to shortfalls in local mitigation as ranges to reflect funding streams, communities

44 Texas Water Development Board | State Flood Assessment potentially need access to more public support. The public must streamflow, and related data— than $18.0 billion in additional understand the benefits of flood on an ongoing basis and with financial assistance. mitigation and the risk of inac- distribution of that data through tion. Local and regional govern- an online repository. Efforts to Communities depend heavily on ments will need public support improve flood risk mapping state and federal dollars to sup- to finance costly projects and to would support the creation of plement local flood budgets. As support wider implementation of new and updated FIRMs, as well a result, flood issues may persist flood mitigation and floodplain as the development of inunda- and projects may remain on hold management strategies. tion maps to aid in land-use for years until a catastrophic planning and emergency re- event results in an allocation of 2 - Improve flood risk sponse. In addition to updated post-disaster funding. Stakehold- mapping: Communities in FIRMs, stakeholders desire ad- ers expressed a desire to pro- Texas rely on FIRMs to identify ditional modeling to determine actively address flooding issues and mitigate local flood risk. base flood elevations and flood- rather than wait for post-disaster The average age of a Texas way designations, especially in recovery funds. FIRM is 13 years old, though light of the recent publication of FIRM age varies widely across Stakeholders also identified a lack Atlas 14, Volume 11. This infor- the state. An urban city typically mation is essential for floodplain of funding as an impediment to has a FIRM that is less than 11 conducting the planning studies administrators to develop and years old; contrast this with a enforce floodplain ordinances. necessary to identify solutions 27-year old FIRM in the Panhan- to known flooding issues. Many dle. Many FIRMs, therefore, do Stakeholders recognized the communities further lack the not account for the last decade importance of improved mapping staff and ability to hire for these or more of development. for use in communicating the full services, a situation which leaves spectrum of flood risk, beyond the the risk of flooding potentially un- Stakeholders strongly support- simplified information provided by identified as well as unresolved. ed all aspects of the flood risk FIRMs. They also listed the need mapping process—including Ultimately, implementation of to develop maps to represent the collection and use of updated flood risk posed by stormwater more robust financing for flood topographic (lidar), rainfall, mitigation also will require broad flooding as a top priority.

Mapping is the first step to identifying and communicating the full spectrum of flood risk.

State Flood Assessment | Texas Water Development Board 45 3 - Encourage watershed- emergency managers, regional management training, and techni- based flood planning: development councils, trans- cal assistance—as a top concern. Stakeholders consistently portation planners, realtors, expressed a preference for a scientists, engineers, businesses, Recent flood disasters highlight regional approach to flood industry, and private citizens to the lack of understanding of the planning, whereby watershed join floodplain administrators true risks posed by flooding. boundaries define the planning in studying and determining the Risks are poorly communicated areas. This sentiment is most appropriate solutions for by limited outreach tools and a consistent with stakeholder calls their unique flooding issues. A misunderstanding of the informa- for increased collaboration, goal of watershed-based plan- tion provided on FIRMs. Effective coordination, and leadership ning is to identify multi-benefit outreach begins by reimagining among all entities with flood solutions to common flooding FIRMs to communicate gradients responsibilities. Further, state and problems and to bring about effi- of risk, not simply boundaries federal agencies indicated that a ciency in implementing projects. between safe and not safe. regional process would increase 4 - Expand educational out- Floodplain administrators specif- the potential for greater inter- ically voiced concerns about how agency collaboration. reach and technical assistance: Stakeholders expressed misinformation leads to question- Stakeholders strongly believe consensus about the need for able permitting decisions or even flood planning should be focused flood-related education in Texas violations of existing floodplain at the local level with funding and the importance for the state development ordinances. They support from the state and ad- to invest resources for this pur- recommended expanding flood- ministrative support carried out pose. Floodplain administrators, plain management outreach for by a regional entity. The process local officials, and emergency homeowners and renters, home- should include a wide variety response personnel all identi- buyers and sellers, insurance of stakeholders and expertise, fied education—in the form of agents, decision makers, and ev- including local decision makers, public awareness, floodplain eryone in between through broad public awareness campaigns and

Floodplain administrators, local officials, and emergency response personnel all identified education—in the form of public awareness, floodplain management training, and technical assistance—as a top concern.

46 Texas Water Development Board | State Flood Assessment targeted professional training for complexities they pose for flood 8.6 Laying a specific interest groups. risk identification and mitigation. This risk can only be reduced foundation with Technical assistance related to the through mitigation of existing science and data NFIP, hazard mitigation planning, problem areas and avoidance via Sound science and data, identi- and grant procurement and ad- proper planning and preparedness. fied as core elements of effective ministration also featured prom- planning, are needed to inform inently in stakeholder views. Flood- flood-related decision making. plain administrators requested 8.5 Benefits of As such, the TWDB has request- access to more free and low-cost acting now ed an additional $4.45 million options for completing training in appropriations from the 86th courses for continuing education Flood mitigation activities, not un- Texas Legislature to support the purposes and for more technical like scientifically supported water agency’s current efforts to gath- guidance in navigating state and supply projects, can be expensive er data and monitor conditions federal financial programs. but ultimately represent sound financial investments. Many of across the state and to develop our state’s reservoirs, originally new initiatives that will further 8.4 Impact of built as flood control and water our understanding of flooding in doing nothing supply measures, have contained Texas and our capacity to share catastrophic floods, sometimes that information. Specifically, the Due to a combination of popula- shortly after their construction. funding requested would allow tion growth and related develop- These types of projects were sited the TWDB to develop hydraulic ment, Texas can be certain that and developed using broadly river models for priority water- without proper planning, flood accepted models and datasets sheds; update reservoir flood events will impact more lives and that served as common founda- pool measurements; expand the cause more damage in the future. tions for project development and TexMesonet earth observation This statement is just as true on evaluation, affording the op- network; acquire high-resolution the High Plains near Post as it portunity to evaluate impacts on land surface (lidar) data to better is along Dickinson Bayou near neighboring communities. Using predict floodplains and flooding Galveston. We acknowledge the such sound science throughout levels; develop coastal circulation limitations of using only FIRMs the process ensures that projects and rainfall-runoff models; and while simultaneously relying on have long-term, positive benefits create a web-based flood dash- them to communicate flood risk for communities. board/water data hub. locally. In addition, FIRMs represent conditions at the time the Once implemented, many flood The information developed map was approved. Any changes mitigation projects save far through these efforts will assist related to land use or mitigation more money and provide more flood forecasters, emergency re- that occur after map publication benefits related to damage pre- sponders, floodplain administra- are not included, further limiting vention than the cost to imple- tors and their local governments, our view of risk. A recent analysis ment them. In fact, studies have and all Texans in making informed by Berg (2018) highlights an ad- shown that mitigation strategies decisions when preparing for, ditional consideration: peak flows for riverine flooding save $7 responding to, and recovering at stream gages in urban areas for every $1 spent (Multihazard from floods. With better data and have increased in many areas Mitigation Council, 2017). Imple- better science, Texas can continue across the state over the past sev- mentation of flood mitigation working toward the common goal eral decades. As our population strategies, developed through of protecting lives and property continues to grow rapidly, and sound mapping and modeling from the next flood event. because most of that growth is built on accurate, up-to-date projected to occur in and around data, can reduce or prevent urban centers, we must consider property damage and loss, overlapping stormwater, riverine, death and injury, and impacts to and coastal hazards and the all sectors of the economy.

State Flood Assessment | Texas Water Development Board 47 9. Recommendations to the 86th Texas Legislature

General flood recommen- three pillars will be guided by flood mitigation. These policies dations: The legislature should foundational flood risk manage- and goals will pursue proactive statewide flood ment policies and goals sup- mitigation by first developing ported by the 2018 State Flood provide the foundation upon foundational flood risk manage- Assessment and is based on these which the other flood recom- ment policies and goals that will underlying core principles: mendations will rest; support three key pillars of invest- serve as a statewide minimum ment: (1) improved and updated Up-to-date data, science, and threshold for addressing flood flood mapping and modeling; technical tools are necessary risks that may, however, be (2) coordinated watershed-based to inform decision making exceeded by local entities using planning; and (3) mitigation by local, regional, and state their own resources to further efforts, such as policy enhance- leadership. reduce local flood risks; ments, increased technical assis- Planning should be conduct- largely determine the frame- tance, and financial assistance for ed at a watershed level with work, scope, and nature of project implementation. the common, minimum aim the work tasks that must be of addressing flood risk man- performed as part of any state agement policies and goals, 9.1 Background or regional flood planning using the best technical tools process, irrespective of the Preliminary findings from the available, according to a format or stakeholder mem- 2018 State Flood Assessment— standardized state framework. bership of such a planning an overview of flood-related Financial assistance should process; and roles and responsibilities, an be provided to those mitiga- estimation of flood mitigation guide the responsible stew- tion projects that meet the ardship of any future invest- costs, and a synopsis of stake- statewide flood risk mitiga- holder views on the future of ments by the state in flood tion goals and that (1) will mitigation. flood planning in Texas—support have no harmful effects on the need for three key pillars of upstream or downstream The legislature should identi- state investment: (1) mapping neighbors and (2) are the fy specific flood risk reduction and science, (2) planning, and product of a planning process goals and an acceptable level (3) structural and non-structural based on a standardized state of risk that will remain even after mitigation. Stakeholders involved framework. the state goals are fully met. in the assessment identified the Absolute protection against all need for additional resources potential flood hazards is not directed toward floodplain 9.2 Specific flood possible and state resources to management and mitigation. recommendations protect against or mitigate flood They also expressed a need for and further back- risk are limited. So, Texas must expanded educational outreach decide both to what end and to and technical assistance oppor- ground what degree it is willing to invest tunities throughout the state. Develop a statewide flood state resources to reduce cer- risk management policy: tain flood risks. An achievable These priorities emerged from The legislature should develop a statewide risk reduction goal myriad suggestions and reflect state flood risk management policy might be, for example, to focus areas of broad consensus among and goals by which to guide on ensuring the protection of all stakeholders. The recommen- state-funded investments in flood lives at risk from up to a 0.2 per- dation to invest in the following mapping, flood planning, and cent annual chance event (often

48 Texas Water Development Board | State Flood Assessment Mapping can save lives. In 2015, this map was used to identify a safe evacuation route for livestock.

called the 500-year flood), or the Much of Texas is either unmapped Through support from the Of- goal might be to minimize loss of or uses out-of-date flood in- fice of the Governor and the property and lives at risk from a surance rate maps, leading to Texas Legislature, the TWDB has 1 percent annual chance event widespread misunderstanding implemented new initiatives in (the 100-year flood). about true flood risks. Mapping recent years to better prepare the is the first step in identifying and state for flood events. To continue These goals, once established, communicating the full spectrum will provide a foundation for the expanding these efforts and to of flood risk. However, FEMA’s improve data collection, mapping, three pillars of state investment as insurance maps show the bound- outlined below. and monitoring of conditions ary of inundation for a specific across the state, the agency has annual chance flood event—of- (1) Mapping requested an additional $4.45 ten misinterpreted as the line million in appropriations from The legislature should provide between safe and not safe. These the 86th Texas Legislature. The additional financial invest- maps are narrowly focused on requested funding represents ment in modeling, mapping, one level of flood risk; may not a small step toward the goal and flood-related science reflect flood potential based on of ensuring that Texas is better to ensure that Texas better the most current topographic, informed and prepared when understands flood risk and is land use, or rainfall data; and flooding events occur, but a better prepared when flooding effectively limit the picture of more significant investment will events occur. The legislature flood risk. be needed to ensure that all should set a goal of devel- areas of the state have accurate oping or updating flood risk Above and beyond mapping, sound science and data are flood models and associated maps across the state, using flood risk maps. current data and technology the core elements of effective standards, by 2030. planning and flood mitigation.

State Flood Assessment | Texas Water Development Board 49 (2) Planning planning benchmark; the next 10 years are estimated The legislature should invest in planning principles, processes, to be more than $31.5 billion; coordinated, watershed-based products, and responsibilities; however, that estimate is derived flood planning to meet state and from limited stakeholder data and not based on any common, flood risk management pol- a methodology for estimating icies and goals. The format statewide flood risk mitigation costs and, as necessary, de- goal. Due to shortfalls in local and structure of a flood termining cost-benefit ratios. planning process should be funding, communities may need largely determined by state (3) Mitigation Assistance approximately $18 to $27 billion flood risk policies and goals in financial assistance. (These es- The legislature should devel- timates account only for mitiga- and should rely on the best op a long-term, affordable, available science. tion costs based on stakeholder and sustainable method to input. They do not account for Although local planning efforts provide financial assistance projects associated with Hur- already take place across the and other incentives for de- ricane Harvey recovery, other state, there is not a unified, veloping and updating flood large federal projects such as the coordinated process to assess maps, statewide flood plan- Coastal Spine or third reservoir risk and plan for the state’s flood ning, and implementing flood being discussed for the Houston risk goals. Instead, planning and mitigation projects that are area, or rehabilitation of high project implementation occurs recommended to meet state hazard dams within the state.) based on varying risk acceptance flood risk management goals. levels and in a piecemeal fashion. Additional financial invest- It is imperative that any financial Implementing flood mitigation ment is needed to support assistance or other incentive without a coherent approach or training and educating flood- provided by the state for flood sound scientific data, proper map- plain administrators, elected mitigation implementation should ping, and coordinated planning officials, emergency respond- be conditioned on a require- may be ineffective, or, worse, ers, and others involved in ment that projects will have no may intensify flood impacts in flood-related issues and to harmful effects on upstream or upstream or downstream com- provide technical assistance downstream neighbors and are munities. to local governments seeking recommended to meet state flood state and federal funding for risk mitigation goals as part of a The foundation of a standardized projects. state flood planning process. planning framework should be flood risk management policies Prior to any formalized statewide and goals as accomplished or regional flood planning pro- through a stakeholder-driven cess, the legislature should estab- process. A state flood planning lish a near-term funding option to process would require clearly allow communities’ access to local establishing match funding to support future mitigation activities or to respond the defined roles for local, quickly to federal funding opportu- state, regional, and federal nities following disaster events. entities in flood planning; Significant investment is required a common vocabulary of to mitigate flooding in Texas. terms; Though the responsibility to the purpose, scope, scale, prepare for and mitigate flood time frame, and priorities of impacts is primarily local, most state flood risk planning and communities do not have the mitigation; economic resources required to an appropriate state flood accomplish their goals. State- wide flood mitigation costs over

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