Flood Risk Report. Guadalupe Blanco River Basin. October 2016

Transcription

1 Flood Risk Report Guadalupe Blanco River Basin Upper Guadalupe, Middle Guadalupe, San Marcos, and Lower Guadalupe (HUC8s ) October 2016 [Type here] [Type here] [Type here]

2 Flood Risk Report History Version Number Version Date Summary 1.0 October 17, 2016 Physical Map Revision Delivery Areas 1, 2, and 3

3 Draft Copy Preface The Department of Homeland Security, Federal Emergency Management Agency s (FEMA) Risk Mapping, Assessment, and Planning (Risk MAP) program provides States, Tribes, and local communities with flood risk information, datasets, risk assessments, and tools that they can use to increase their resilience to flooding and better protect their residents. By pairing accurate floodplain maps with risk assessment tools and planning and outreach support, Risk MAP transforms the traditional flood mapping efforts into an integrated process of identifying, assessing, communicating, planning for, and mitigating flood-related risks. This Flood and Natural Hazard Risk Report provides datasets for floods and other natural hazards to help local or Tribal officials, floodplain managers, planners, emergency managers, and others better understand their flood risk, take steps to mitigate those risks, and communicate those risks to their residents and local businesses. Flood risk often extends beyond community limits. This report provides flood risk data for the Guadalupe-Blanco River Basin and its four watersheds: Upper Guadalupe, Middle Guadalupe, San Marcos, and Lower Guadalupe. Flood risk is always changing, and studies, reports, or other sources may be available that provide more comprehensive information. This report is not intended to be regulatory or the final authoritative source of all flood risk data in the project area. Rather, it should be used in conjunction with other data sources to provide a comprehensive picture of flood risk within the project area. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October 2016 i

4 Contents Executive Summary...3 About the Guadalupe-Blanco River Basin... 3 About the Physical Map Revision... 4 Introduction...6 Flood Risk... 6 Watershed Basics... 7 Project Phases and Map Maintenance Background How are FEMA s Flood Hazard Maps Maintained? General Flood Risk Project Phases Phase Zero: Investment Phase One: Discovery Phase Two: Risk Identification and Assessment Phase Three: Regulatory Products Update Phase Zero: Investment Watershed Selection Factors Base-Level Engineering Phase One: Discovery Future Investments for Refinement Phase Two: Risk Identification and Assessment Flood Hazard Refinement Community Collaboration Flood Risk Review Meeting Next Steps Potential Community Activities Phase Three: Regulatory Product Update Flood Insurance Study Report Flood Insurance Rate Map Panels DFIRM Database Letters of Map Change Next Step: Preliminary Issuance Steps after the Preliminary Issuance GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

5 Future Physical Map Revisions Appendix I: Community-Specific Reports Appendix II: Mitigation Tactics What is Mitigation? Local Mitigation Plans Best Practices in Your Area Appendix II: Resources State Partners Watershed Follow Up Points of Contact Texas Water Development Board Guadalupe-Blanco River Authority Texas Floodplain Management Association (TFMA) Certified Floodplain Manager (CFM) Certification Texas Quick Guide Interactive Preliminary Data Viewer (maps.riskmap6.com) Map Service Center Preliminary Map Data GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

6 Executive Summary The Federal Emergency Management Agency s (FEMA) Risk Mapping, Assessment, and Planning (Risk MAP) program provides communities with flood information to help them understand their current flood risk and make informed decisions about taking action to become stronger and more resilient in the face of future risk. The Risk MAP process provides communities with new or improved information about their flood risk based on watershed models that use information from local, regional, State, and Federal sources. Communities can use the resulting tools and data to enhance mitigation plans and better protect their residents. This report is one such tool for communities impacted by the Physical Map Revision (PMR) resulting from an updated flood hazard analysis of the Guadalupe-Blanco River Basin. The Flood Risk Report has two goals: (1) inform communities of their risks related to certain natural hazards, and (2) enable communities to act to reduce their risk. It is intended to assist Federal, State, and local officials with the following: Update local hazard mitigation plans and community comprehensive plans Update emergency operations and response plans Communicate risk Inform the modification of development standards Identify mitigation projects Most importantly, the PMR includes 58 updated Flood Insurance Rate Map (FIRM) panels covering the cities of Luling, Martindale, San Marcos, Staples, Wimberley, and Woodcreek, and the counties of Caldwell, Comal, Guadalupe, Gonzales, and Hays. During this phase of the process, communities are encouraged to review these panels closely and provide feedback to FEMA Region 6, based on their local knowledge. About the Guadalupe-Blanco River Basin The first FEMA flood hazard mapping of the Guadalupe Basin was released more than 35 years ago. Over the years, the area has experienced recurring severe floods and rapidly increasing development. Since 2011, the Guadalupe-Blanco River Authority (GBRA), in coordination with local communities, has been working throughout the basin to determine the flood concerns and risk in their 10-county jurisdictional area. They have also coordinated with adjacent river authorities for contributing areas outside of their county jurisdiction. Accordingly, when the historic flash and river flooding occurred across portions of South-Central Texas over Memorial Day weekend in 2015, the GBRA had already been working with local, State, and national partners, including the U.S. Army Corps of Engineers (USACE) and the Texas Water Development Board. In February 2015, the USACE completed hydrologic modeling called CWMS (Corps Water Management Systems) along the Guadalupe River and provided the results to both the GBRA and FEMA for consideration. Figure 1: June 26, The bridge on Fisher Store Road GUADALUPE-BLANCO RIVER BASIN RISK REPORT October 2016 in Wimberley, TX was destroyed by storms and 3 flooding.

7 Following the May 2015 Floods in Central Texas, the CWMS and GBRA data were included in the statistical analysis that made up the Advisory Base Flood Elevation (ABFE) data. In coordination with the GBRA and USACE, two additional refinements of the hydrology were made to CWMS. This refined hydrology was used in the development of the Physical Map Revision. About the Physical Map Revision Through coordination and data sharing, the GBRA served as an excellent partner in the PMR effort. Additionally, the City of San Marcos provided a Master Drainage Plan, and FEMA coordinated with the GBRA and the USACE to complete and share hydrologic modeling data. FEMA also initiated Base Level Engineering (BLE) for the four HUC8 sub-basins (see map page 19) that make up the Guadalupe-Blanco River Basin. This ongoing project in the Guadalupe-Blanco Basin will inform broader discussions on risk once it is complete. The results of the Base Level Engineering analysis will be shared in late 2016, and the Flood Risk Report will be updated to reflect that additional data. Using the Base Level Engineering approach, FEMA will prepare flood hazard information for approximately 6,600 miles of streams, adding over 1,600 stream-miles of supplementary flood hazard information for communities throughout the basin. Once complete, this information will be provided to the communities throughout the basin for their planning, risk communication, floodplain management, and permitting activities, and to inform future flood study needs. For information on Discovery (Phase One) of this project, see the Flood Risk Report. To prepare the Physical Map Revision, FEMA used a number of refinements to the data including updated hydrology and hydraulics and additional survey data. These refinements would accomplish the following: Provide more detailed input information for stream crossings that were not surveyed during the analyses by the GBRA or the City of San Marcos; Include the 2015 storm events in the historical analysis record; Analyze additional sub-basins and include new gage locations in the hydrologic analysis; and Prepare a floodway analysis for selected streams. Also, since the project began, FEMA has continued its community engagement with the GBRA, the USACE, the State of Texas, and local communities through several in-person meetings and webinars. Flood Risk Review meetings for the PMR communities took place in September and October Communities received work maps, the H&H models, and the Flood Risk Report for close review. This meeting is held to offer discussions with technical staff, and to guide a review of the effects of the physical and meteorological changes within the project area. Communities are asked to review the flood risk analysis and provide comments back to FEMA and their mapping partners by November 18, Once FEMA has received, reviewed, and responded to all comments and technical data resulting from the Flood Risk Review meeting, the Regulatory Product Update phase will begin. During this phase, the project team will prepare the preliminary FIRMs, Flood Insurance Study reports, and Digital FIRM databases for release. Preliminary versions of these three regulatory products will be sent to each community s Chief Executive Officer and floodplain administrator for their review and feedback. (These GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

8 will also be available for public review on FEMA s Flood Map Service Center: FEMA will remain in contact with communities throughout this process. Preliminary issuance for the PMR is currently targeted for January For more information about ways your community can take action or take advantage of available resources, please review the attached appendices. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

9 Introduction Flood Risk Floods are naturally occurring phenomena that can and do happen almost anywhere. In its most basic form, a flood is an accumulation of water over normally dry areas. Floods become hazardous to people and property when they inundate an area where development has occurred, causing losses. Mild flood losses may have little impact on people or property, such as damage to landscaping or the accumulation of unwanted debris. Severe flood losses can destroy buildings and crops and cause severe injuries or death. Calculating Flood Risk It is not enough to simply identify where flooding may occur. Even if people know where a flood might occur, they may not know the risk of flooding in that area. The most common method for determining flood risk, also referred to as vulnerability, is to identify both the probability and the consequences of flooding: Flood Risk (or Vulnerability) = Probability x Consequences; where Probability = the likelihood of occurrence Consequences = the estimated impacts associated with the occurrence The probability of a flood is the likelihood that it will occur. The probability of flooding can change based on physical, environmental, and/or engineering factors. Factors affecting the probability that a flood will have an impact an area range from changing weather patterns to the existence of mitigation projects. The ability to assess the probability of a flood, and the level of accuracy for that assessment, are also influenced by modeling methodology advancements, better knowledge, and longer periods of record for the water body in question. The consequences of a flood are the estimated impacts associated with its occurrence. Consequences relate to human activities within an area and how a flood affects the natural and built environment. The Flood Risk Report has two goals: (1) inform communities of their risks related to certain natural hazards, and (2) enable communities to act to reduce their risk. The information within this Risk Report is intended to assist Federal, State and local officials to: Communicate risk Local officials can use the information in this report to communicate with property owners, business owners, and other residents about risks and areas of mitigation interest. Update local hazard mitigation plans and community comprehensive plans Planners can use risk information to develop and/or update hazard mitigation plans, comprehensive plans, future land use maps, and zoning regulations. For example, zoning codes can be changed to provide for more appropriate land uses in high-hazard areas. Update emergency operations and response plans Emergency managers can identify high-risk areas for potential evacuation and low-risk areas for sheltering. Risk assessment information GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

10 may show vulnerable areas, facilities, and infrastructure for which continuity of operations plans, continuity of government plans, and emergency operations plans would be essential. Inform the modification of development standards Planners and public works officials can use information in this report to support the adjustment of development standards for certain locations. Identify mitigation projects Planners and emergency managers can use this risk assessment to determine specific mitigation projects of interest. For example, a floodplain manager may identify critical facilities that need to be elevated or removed from the floodplain. This report showcases risk assessments, which analyze how a hazard affects the built environment, population, and local economy, to identify mitigation actions and develop mitigation strategies. The following are some of the resources used to prepare and compile this report: Approximately 6,600 miles of Base-Level Engineering data and 212 miles of detailed studies supported the development of the Flood Risk and Natural Hazard datasets and report. The hazard mitigation plans prepared by the GBRA, the Alamo Area Council of Governments, and Hays County effectively allowed FEMA to assess hazards identified through local, State, and Federal partnerships and mitigation action items. Risks such as socioeconomic and dam failure are assessed through vulnerability assessments. Information to assess potential community losses was collected for local assets or resources at risk from certain hazards, the physical features and human activities that contribute to that risk, and the location and severity of the hazard. The information in this report should be used to identify areas for mitigation projects as well as for additional efforts to educate residents on the hazards that may affect them. The areas of greatest hazard impact are identified in the Areas of Mitigation Interest section of this report, which can serve as a starting point for identifying and prioritizing actions a community can take to reduce its risks. Watershed Basics Historically, 70 to 80 percent of all natural disasters in the United States have involved flooding. Some 20 million of the 171 million acres that make up Texas are floodprone more than in any other State. While flash floods are known to occur throughout the State, the Hill Country is known as flash flood alley. According to Richard Earl, a geographer at Southwest Texas State University, the Hill Country is more susceptible to flooding because of its thin soils with large areas of exposed bedrock and relatively sparse vegetation, which produce rapid runoff. The Balcones Escarpment to the north of this river basin is also a trigger for storm formation. William Asquith, a hydrologist with the U.S. Geological Survey (USGS), believes that the steep slopes of the Hill Country produce some of the highest runoff rates in the United States and possibly the world. The region is an elephant s graveyard for tropical cyclones, which crash into the Texas Gulf Coast and often stall over the Hill Country, where they spend themselves, releasing raging torrents as they die. The stream reaches within the Guadalupe-Blanco River Basin under this Risk MAP project include the San Marcos River from the Hays-Caldwell County line to the confluence with Guadalupe River and the Guadalupe River from downstream of Canyon Dam, through Victoria County, to the confluence with the GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

11 San Antonio River. In addition to these sections of the rivers, the San Marcos and Blanco River watershed drainage areas in Hays and Blanco Counties, as well as the drainage area above Canyon Lake, were taken into account. The Basin consists of the Lower, Middle, and Upper Guadalupe and San Marcos watersheds. Figure 2 provides an overview of the Guadalupe-Blanco Basin and its geographic location within the State. Figure 2: Overview of Guadalupe-Blanco River Basin A review of land cover changes and population growth patterns in the basin area revealed that significant development occurred in the last decade along major highway transportation corridors. Particularly affected is the San Antonio-Austin corridor of Interstate Highway 35 (IH-35), which travels northeast across Guadalupe and Comal Counties into the southeastern portion of Hays County, and along State Highway 130 Toll Road (SH-130). Partially due to their locations along IH-35 and their proximity to SH-130, the Cities of New Braunfels and San Marcos have experienced significant population growth. Population totals rose from 40,163 and 36,616 in 2000 to 57,740 and 44,894 in 2010 for New Braunfels and San Marcos, respectively. Population in Hays County, however, increased by 61 percent from 2000 to In addition, Hays is the county with the second most significant development and economic growth in Texas for that time GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

12 period. The City of Kyle, situated in Hays County along IH-35 and having an area of only 19 square miles, tripled in population from 2000 to 2010, from 6,651 (2000) to 28,016. Population and land area characteristics of the Guadalupe-Blanco Basin Risk MAP project area are shown in Table 1. Table 1: Population and Area Characteristics 1 Risk MAP Project Total Population in Deployed Area Average % Population Growth/Yr ( ) Predicted Population (by 2021) Land Area Developed Area Open Water Guadalupe-Blanco Basin 486, % 636,826 5,937 mi 2 1,763 mi mi 2 Excluding the combined areas of previously developed land and open water, roughly 3,900 mi 2 of the basin still has the potential for new construction. Using the average annual growth rate for the cities and unincorporated county areas in the project area, the total population within the watersheds has the potential to rise to over 600,000 by Therefore, the probability is high that populated areas will expand and rural land will be developed. To help mitigate the risk to areas where increased population and development are expected, communities can adopt (or exceed) the minimum standards of the National Flood Insurance Program (NFIP). This is recommended as a proactive strategy to manage construction within the floodplain and avoid negative impacts to existing and future development. To increase mitigation efforts and community flood awareness through potentially discounted premium rates, an NFIP community that has adopted more stringent ordinances or is actively completing mitigation and outreach activities is encouraged to consider joining the Community Rating System (CRS). The CRS program is a voluntary incentive-based program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions. Most communities within the project area have a level of regulation, suitable for managing floodplains with mapped regulatory floodways and Base (1-percent-annual-chance) Flood Elevations (44 CFR 60.3(d)). Three communities Garden Ridge, Nixon, and Yorktown adopted ordinances based on the currently effective NFIP flood hazard data, which shows Zone A Special Flood Hazard Areas (SFHAs) without published flood elevations (44 CFR 60.3(b)). Communities can review their current ordinances and reflect potential flood hazard changes by adopting updated ordinances early. This action can reduce future flood losses by affecting how substantial 1 Data obtained from the U.S. Census Bureau; ESRI Demographic 5-year Projections; and National Land Cover Database 2 Data obtained FEMA Community Information Systems. 3 Data obtained USACE National Inventory of Dams 4 SID 5 notes, no flooding source will receive a lower level of regulatory flood map product than what currently GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

13 improvements or new construction are regulated. Table 2 depicts NFIP and CRS participation status and provides an overview of the effective flood data availability. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

14 Table 2: NFIP and CRS Participation 2 Risk MAP Project Participating NFIP Communities/ Total Communities Number of CRS Communities CRS Rating Class Range Average Years since FIRM Update Level of Regulations (44 CFR 60.3) Guadalupe-Blanco Basin 63/ (b), 60.3(d) The basin s populated areas near rivers and streams are known for tourism and seasonal living due to their recreational activities and abundant water resources. Dams along these 5,010 documented stream miles are used to maintain water storage and to control or divert flow. As recorded by the USACE in the National Inventory of Dams, 167 dams are within the basin, and 37 of these are considered high-hazard dams. For these dams, the owners and operators are required to develop and maintain Emergency Action Plans to reduce the risk of loss of life and property if the dam fails. Table 3 provides the characteristics of the dams identified in the project area. Canyon Lake Dam maintains the highest total storage space below the maximum attainable water-surface elevation, including any surcharge storage, at 1,208,350 acre-feet. Table 3: Risk MAP Project Dam Characteristics 3 Risk MAP Project Total Number of Identified Dams Number of Dams Requiring EAP Percentage of Dams without EAP Average Years since Inspection Average Storage (acre-feet) Guadalupe-Blanco Basin: (HUC8s: , , , and ) % ,306 Project Phases and Map Maintenance Background FEMA manages several risk analysis programs, including Flood Hazard Mapping, National Dam Safety, Earthquake Safety Program, Multi-Hazard Mitigation Planning, and Risk Assessment Program, that assess the impact of natural hazards and lead to effective strategies for reducing risk. These programs support the Department of Homeland Security s objective to strengthen nationwide preparedness and mitigation against natural disasters. 2 Data obtained FEMA Community Information Systems. 3 Data obtained USACE National Inventory of Dams GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

15 FEMA manages the NFIP, which is the cornerstone of the national strategy for preparing American communities for flood hazards. In the Nation s comprehensive emergency management framework, the analysis and awareness of natural hazard risk remains challenging. For communities to make informed risk management decisions and take action to mitigate risk, a consistent risk-based approach to assessing potential vulnerabilities and losses is needed, as well as tools to communicate the message. Flood hazard mapping remains a basic and critical component for a prepared and disaster-resilient Nation. Flood-related damage between 1980 and 2013 totaled $260 billion, but the total impact to our Nation was far greater more people lose their lives annually from flooding than any other natural hazard. FEMA, Federal Flood Risk Management Standard (FFRMS) (2015) In Fiscal Year 2009, FEMA s Risk MAP program began to synergize the efforts of Federal, State, and local partners to create timely, viable, and credible information identifying natural hazard risks. The intent of the Risk MAP program is to share resources to identify the natural hazard risks a community faces and ascertain possible approaches to minimizing them. Risk MAP aims to provide technically sound flood hazard information to be used in the following ways: To update the regulatory flood hazard inventory depicted on FIRMs and the National Flood Hazard Layer To provide broad releases of data to expand the identification of flood risk (flood depth grids, water surface elevation grids, etc.) To support sound local floodplain management decisions To identify opportunities to mitigate long-term risk across the Nation s watersheds GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

16 How are FEMA s Flood Hazard Maps Maintained? FEMA s flood hazard inventory is updated through several types of revisions. Community-submitted Letters of Map Change. First and foremost, FEMA relies heavily on the local communities that participate in the NFIP to carry out the program s minimum requirements. These requirements include the obligation for communities to notify FEMA of changing flood hazard information and to submit the technical support data needed to update the FIRMs. Although revisions may be requested at any time to change information on a FIRM, FEMA generally will not revise an effective map unless the changes involve modifications to SFHAs. Be aware that the best floodplain management practices and proper assessments of risk result when the flood hazard maps present information that accurately reflects current conditions. Under the current minimum NFIP regulations, a participating community commits to notifying FEMA if changes take place that will affect an effective FIRM no later than 6 months after project completion. Section 65.3, Code of Federal Regulations Letters of Map Amendment (LOMA). The scale of an effective FIRM does not always provide the information required for a site-specific analysis of a property s flood risk. FEMA s LOMA process provides homeowners with an official determination on the relation of their lot or structure to the SFHA. Requesting a LOMA requires a homeowner to work with a surveyor or engineering professional to collect site-specific information related to the structure s elevation; it may also require the determination of a site-specific Base Flood Elevation (BFE). Fees are associated with collecting the survey data and developing a site-specific BFE. Local survey and engineering professionals usually provide an Elevation Certificate to the homeowner, who can use it to request a LOMA. A successful LOMA may remove the Federal mandatory purchase requirement for flood insurance, but lending companies may still require flood insurance if they believe the structure is at risk. FEMA-Initiated Flood Risk Project. Each year, FEMA initiates a number of Flood Risk Projects to create or revise flood hazard maps. Because of funding constraints, FEMA can study or restudy only a limited number of communities, counties, or watersheds. As a result, FEMA prioritizes study needs based on a cost-benefit approach whereby the highest priority is given to studies of areas where development has increased and the existing flood hazard data has been superseded by information based on newer technology or changes to the flooding extent. FEMA understands communities require products that reflect current flood hazard conditions to best communicate risk and implement effective floodplain management. Flood Risk Projects may be delivered by FEMA or one of its Cooperating Technical Partners (CTPs). The CTP initiative is an innovative program created to foster partnerships between FEMA and participating NFIP communities, as well as regional and State agencies. Qualified partners collaborate in maintaining up-to-date flood maps. In Region 6, CTPs are generally state-wide agencies that house the State Floodplain Administrator. However, some Region 6 CTPS are also large River Authority or Flood Control Districts. They provide enhanced coordination with local, State, and Federal entities, engage community GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

17 officials and technical staff, and provide updated technical information that informs updates to the national flood hazard inventory. Risk MAP has modified FEMA s project investment strategy from a single investment by fiscal year to a multi-year phased investment, which allows the Agency to be more flexible and responsive to the findings of the project as it moves through the project lifecycle. Flood Risk Projects are funded and completed in phases. General Flood Risk Project Phases Each phase of the Flood Risk Project provides both FEMA and its partner communities an opportunity to discuss the data that has been collected to determine a path forward. Local engagement throughout each phase of the project enhances the opportunities for partnership and discussion about current and future risk, as well as offering the opportunity to identify projects and activities that local communities may pursue to reduce their long-term natural hazard risk. Flood Risk Projects may be funded for a number of the following phases: Phase Zero Investment Phase One Discovery Phase Two Risk Identification and Assessment Phase Three Regulatory Product Update Local input is critical throughout each phase of a Flood Risk Project. More detail about the tasks and objectives of each phase are included below. Phase Zero: Investment Phase Zero of a Flood Risk Project initiates FEMA s review and assessment of the inventories of flood hazards and other natural hazards within a watershed area. During the Investment Phase, FEMA reviews the availability of information to assess the current flood plain inventory. FEMA maintains a number of data systems to perform watershed assessments and selects watersheds for a deeper review of available data and potential investment tasks, based on the following factors: Availability of High-Quality Ground Elevation. FEMA reviews readily available and recently acquired ground elevation data. This information helps identify development and earth-moving activities in the vicinity of streams and rivers. Where necessary, FEMA may partner with local, State, and other Federal entities to collect necessary ground elevation information within a watershed. If high-quality ground elevation is both available for a watershed area and compliant with FEMA s quality requirements, FEMA and its mapping partners may prepare engineering data to assess, revise, replace, or add to the current flood hazard inventory. Mile Validation Status within Coordinated Needs Management Strategy (CNMS). FEMA uses the CNMS database to track the validity of the flood hazard information prepared for the NFIP. The CNMS database reviews 17 criteria to determine whether the flood hazard information shown on the current FIRM is still valid. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

18 Communities may also inform and request a review or update of the inventory through the CNMS website at The CNMS Tool Tutorial provides an overview of the online tool and explains how to submit requests. Local Hazard Mitigation Plans. Reviewing current and historic hazard mitigation plans provides an understanding of a community s comprehension of its flood risk and other natural hazard risks. The mitigation strategies within a local hazard mitigation plan provide a lens to local opportunities and underscore a potential for local adoption of higher standards related to development or other actions to reduce long-term risk. Cooperating Technical Partner State Business Plans. In some States, a CTP generates an annual State business plan that identifies future Flood Risk Project areas that are of interest to the State. In the State of Texas, both the Guadalupe-Blanco River Authority and the Texas Water Development Board (TWDB) are active CTPs. In this project area, FEMA has worked closely with both entities to develop the project scope and determine the necessary project tasks. Communities that have identified local issues are encouraged to indicate their data needs and revision requests to the State CTP so that they can be prioritized and included in the State Business Plans. Possible Investment Tasks. After a review of the data available within a watershed, FEMA may choose to (1) purchase ground elevation and/or (2) create some initial engineering modeling against which to compare the current inventory. This type of modeling is known as Base-Level Engineering. Phase One: Discovery Phase One, the Discovery Phase, provides opportunities both internally (between the State and FEMA) and externally (with communities and other partners interested in flood potential) to discuss local issues with flooding and examine possibilities for mitigation action. This effort is made to determine where communities currently are with their examination of natural hazard risk throughout their community and to identify how State and Federal support can assist communities in achieving their goals. The Discovery process includes an opportunity for local communities to provide information about their concerns related to natural hazard risks. Communities may continue to inform the project identification effort by providing previously prepared survey data, as-built stream crossing information, and engineering information. For a holistic community approach to risk identification and mapping, FEMA relies heavily on the information and data provided at a local level. Flood Risk Projects are focused on identifying (1) areas where the current flood hazard inventory does not provide adequate detail to support local floodplain management activities, (2) areas of mitigation interest that may require more detailed engineering information than is current available, and (3) community intent to reduce the risk throughout the watershed to assist FEMA s future investment in these project areas. Watersheds are selected for Discovery based on these evaluations of flood risk, data needs, availability of elevation data, regional knowledge of technical issues, identification of a community-supported mitigation project, and input from Federal, State, and local partners. Possible Discovery Tasks. Discovery may include a mix of interactive webinars sessions, conference calls, informational tutorials, and in-person meetings to reach out to and engage with communities for input. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

19 Data collection, interviews and interaction with community staff, and data-mining activities provide the basis for watershed-, community- and stream-level reviews to determine potential projects that may benefit the communities. A range of analysis approaches are available to determine the extent of flood risk along streams of concern. FEMA and its mapping partners will work closely with communities to determine the appropriate analysis approach, based on the data needs throughout the community. These potential projects may include local training sessions, data development activities, outreach support to local communities wanting to step up their efforts, or the development of flood risk datasets within areas of concern, to allow a more in-depth discussion of risk. Phase Two: Risk Identification and Assessment Phase Two (Risk Identification and Assessment) continues the risk awareness discussion with communities through watershed analysis and assessment. Analyses are prepared to review the effects of physical and meteorological changes within the project watershed. The new or updated analysis provides an opportunity to identify how development within a watershed has affected the amount of stormwater generated during a range of storm probabilities and shows how effectively stormwater is transported through communities in the watershed. Coordination with a community s technical staff during engineering and model development allows FEMA and its mapping partners to include local knowledge, based on actual on-theground experience, when selecting modeling parameters. The information prepared and released during Phase Two is intended to promote better local understanding of the existing flood risk by allowing community officials to review the variability of the risk throughout their community. As FEMA strives to support community-identified mitigation actions, it also looks to increase the effectiveness of community floodplain management and planning practices, including local hazard mitigation planning, participation in the NFIP, use of actions identified in the CRS Manual, risk reduction strategies for repetitive loss and severe repetitive loss properties, and the adoption of stricter standards and building codes. FEMA is eager to work closely with communities and technical staff to determine the current flood risk in the watershed. During the Risk Identification and Assessment phase, FEMA would like to be alerted to any community concerns related to the floodplain mapping and analysis approaches being taken. During this phase, FEMA can engage with communities and review the analysis and results in depth. Possible Risk Identification and Assessment Tasks. Phase Two may include a mixture of interactive webinars, conference calls, informational tutorials, and in-person meetings to reach out to and engage with communities for input. Flood Risk Project tasks may include hydrologic or hydraulic engineering analysis and modeling, floodplain mapping, risk assessments using Hazus-MH software, and preparation of flood risk datasets (water surface elevation, flood depth, or other analysis grids). Additionally, projects may include local training sessions, data development activities, outreach support to local communities that want to step up their efforts, or the development of flood risk datasets within areas of concern, to allow a more in-depth discussion of risk. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

20 Phase Three: Regulatory Products Update If the analysis prepared in the previous Flood Risk Project phases indicate that physical or meteorological changes in the watershed have significantly changed the flood risk since the last FIRM was printed, FEMA will initiate the update of the regulatory products that communities use for local floodplain management and NFIP activities. Delivery of the preliminary FIRMs and FIS reports begins another period of coordination between community officials and FEMA to discuss the required statutory and regulatory steps both parties will perform before the preliminary FIRM and FIS reports can become effective. As in the previous phases, FEMA and its mapping partners will engage with communities through a variety of conference calls, webinars, and in-person meetings. Once the preliminary FIRMs are prepared and released to communities, FEMA will initiate the statutory portions of the regulatory product update. FEMA will coordinate a Consultation Coordination Officer (CCO) meeting and initiate a 90-day comment and appeal period. During this appeal period, local developers and residents may coordinate the submittal of their comments and appeals through their community officials to FEMA for review and consideration. FEMA welcomes this information because additional proven scientific and technical information increases the accuracy of the mapping products and better reflects the community s flood risks identified on the FIRMs. Communities may host or hold Open House meetings for the public. The Open House layout allows attendees to move at their own pace through a number of stations, collecting information in their own time. This format allows residents to receive one-on-one assistance and ask questions pertinent to their situation or their interest in risk or flood insurance information. All appeals and comments received during the statutory 90-day Appeal Period, including the community s written opinion, will be reviewed by FEMA to determine the validity of the appeal. Once FEMA issues the appeal resolution, the associated community and all appellants will receive an appeal resolution letter and FEMA will make any revisions to the FIRM as appropriate. A 30-day period is provided for review and comment on successful appeals. Once all appeals and comments are resolved, the flood map is ready to be finalized. After the Appeal Period, FEMA will send community leaders a Letter of Final Determination (LFD) stating that the preliminary FIRM will become effective in six months. The letter also discusses the actions each affected community participating in the NFIP must take to remain in good standing in the NFIP. After the preceding steps are complete and the six-month compliance period ends, the FIRMs are considered effective maps and new building and flood insurance requirements become effective. That is a brief general overview of a flood risk project. Next, the Flood Risk Report will provide details on the efforts in Guadalupe-Blanco River Basin. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

21 Phase Zero: Investment The Guadalupe-Blanco River Basin is in the south-central part of Texas. Its mainline streams include the Blanco, Guadalupe, and San Marcos Rivers. These three rivers drain four HUC8 watersheds (Upper Guadalupe, Middle Guadalupe, Lower Guadalupe, and San Marcos) comprising 5,934 square miles of land throughout portions of 13 Texas counties: Blanco, Caldwell, Calhoun, Comal, DeWitt, Goliad, Guadalupe, Gonzales, Hays, Kerr, Kendall, Refugio, and Victoria. BLANCO COUNTY KERR COUNTY GOLIAD COUNTY Figure 3: Guadalupe-Blanco River Authority Counties and Watershed Areas The Guadalupe River runs through Texas from Kerr County to San Antonio Bay on the Gulf of Mexico, and the Blanco and San Marcos Rivers are major tributaries to the Guadalupe. The river basin headwaters begin in the rocky Hill Country counties of Kerr, Kendall, and Blanco. The rivers then pass through the Balcones Escarpment, along the Interstate 35 corridor, and into the rolling hills and flat plains of the coastal counties of Victoria, Calhoun, and Refugio before entering San Antonio Bay and the Gulf of Mexico. The annual rainfall in this basin ranges from 38 inches near the coast to 30 inches in the Hill Country areas. The Guadalupe and San Marcos rivers have several dams along their length, including Canyon Dam upstream of New Braunfels. The river basin footprint is within the area known as flash flood alley, and flood events are sudden, frequent, and costly. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

22 Watershed Selection Factors A number of factors and criteria are reviewed for watershed selection: flood risk, the age of the current flood hazard data, population growth trends and potential for growth, recent flood claims, and disaster declaration history. The availability of local data and high-quality ground elevation data is reviewed for use in preparing flood hazard data. The CNMS database is reviewed to identify large areas of unknown or unverified data for streams. FEMA consults the State of Texas CTP, the State NFIP Coordinator, and the State Hazard Mitigation Officer when basins are identified for study. Flood Risk. People who live along the Guadalupe River and its tributaries are not strangers to flood events, and numerous flooding events are listed in the historical record. The Guadalupe-Blanco River Basin experienced major flooding as recently as October 2015, along the Guadalupe and San Marcos Rivers, as well as their tributaries. Recent major floods in 1991, 1998, 2002, 2004, 2007, 2010, 2012, and 2015 illustrate the ongoing flood threat for the Guadalupe-Blanco River basin. Growth Potential. Although the GBRA service area is largely rural, rapid urbanization is taking place all along the Interstate 35 corridor. Existing and proposed developments are primarily an outgrowth of the cities of Austin and San Antonio, particularly around the cities of New Braunfels and San Marcos. Another notable development has been the construction of the SH 130 Toll Road through Caldwell and Guadalupe Counties. Most local creeks have not been adequately studied, and historical floods indicate that the creeks are inadequate for conveying significant stormwater runoff. These communities are also under increased development pressures, which will result in increased runoff and will require improved drainage systems. Growth along the Austin-San Antonio corridor is most noticeable in the northwest portion of the study area, but development is also increasing rapidly around the SH 130 Toll Road and in many middle- and lower-basin communities, due to the ongoing development of the Eagleford Shale for oil and natural gas. Twice (2002 and 2007) in the last 10 years, counties in the Lower Guadalupe River Basin have been declared major federal disaster areas due to damaging floods. Recently (spring and fall 2015), the communities in the middle of the basin experienced large-scale events leading to some of the largest disasters in the basin. In light of the current development along the tributaries to the Guadalupe and San Marcos Rivers, people are concerned that the area s potential for flood damage still exists and may be increasing. Age of Current Flood Information. The communities of San Marcos, Wimberley, New Braunfels, Seguin, and Victoria are growing rapidly. Industrial and other development in the city of Cuero and elsewhere in DeWitt County are increasing potential for stormwater run-off. The flood hazards for much of the Guadalupe-Blanco River Basin have not been studied since the 1970s, when FEMA s first flood hazard mapping was released. Many of the areas below Canyon Reservoir have never been studied or have outdated information on the current flood hazard map. The combination of repeated severe floods, outdated flood information, and exploding development indicate that this area is in need of updated flood hazard information to support local floodplain management activities. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

23 Local Data Availability - Flood Protection Planning Grant Studies. Various studies of the Guadalupe River and its contributing basin areas are available. In early 2015, the Guadalupe-Blanco River Authority contacted FEMA to begin coordination and sharing data to update FIRMs throughout the basin. The GBRA had secured a Flood Protection Planning grant in 2011 from the TWDB and proposed a federal Flood Damage Reduction Feasibility Study. Its purpose was to conduct a basin-wide watershed study and investigate structural and non-structural flood damage reduction projects, to develop a comprehensive and regionally based Flood Protection Plan for the river basin. The proposed study was prepared to establish a baseline level of understanding the flood potential based on a basin-wide connectivity hydrologic review, to produce hydraulic analysis for local flood damage assessments, floodplain delineation, flood mitigation and ecosystem restoration alternative reviews, improved flood early warning systems, future Letters of Map Change (LOMCs) and BFE determinations to support current and future development. The initial Flood Protection Planning grant studied 26 stream-miles, including: Figure 4: Hydrologic Basins, Guadalupe Flood Protection Planning Grant San Marcos River (Hays County line to confluence with the Guadalupe River) Guadalupe River (Canyon Dam through Victoria County) Plum Creek (in vicinity of Luling) Salt Branch (in vicinity of Luling) Unnamed Tributary (Milam Street to confluence with the San Marcos River) Blieders Creek (near New Braunfels) Dry Comal (near New Braunfels) The GBRA obtained a second Flood Protection Planning grant in 2013 to study an additional 216 stream miles in Caldwell, Comal, DeWitt, Hays and Victoria Counties. The communities of Gonzales, Kyle, Lockhart, Seguin, San Marcos, and Victoria were included in the study areas for the Phase 2 study effort. Support from the Figure 5: Study Streams, Guadalupe Flood Protection Planning Grant Plum Creek Conservation District, York Creek Conservation District, and Dewitt County Drainage District 1 rounded out the community participation in this study effort. These studies were completed in GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

24 The study mileage completed in Phases 1, 2 and 3 through the Flood Protection Planning grant is included in Figure 5. Local Data Availability - City of San Marcos Master Drainage Plan. The City of San Marcos recently completed a number of hydrologic and hydraulic studies within its jurisdictional boundaries for its updated Master Drainage Plan. The community has not yet released the study, but it is providing information to incorporate into the FIRM update within its jurisdictional area. In Figure 6, the mileage shown in green was provided to FEMA for inclusion in future mapping updates. Local Data Availability - Advisory Base Flood Elevation (ABFE) Mapping Effort. Immediately following the flood events in late May 2015, FEMA initiated a discussion with GBRA technical and leadership staff, in coordination with the State of Texas Water Development Board. That coordination led to FEMA s use of the data prepared through the GBRA s Flood Protection Planning grants to develop ABFE information to aid rebuilding and recovery efforts throughout the basin. FEMA in coordination with GBRA and the USACE included the May 2015 storm event in the hydrologic calculations and to prepare and release a series of Flood Recovery Data to severely impacted areas. This data was released to communities along Cypress Creek and the Blanco, Guadalupe, and San Marcos Rivers. The data release included ABFE maps and profiles, as well as Estimated Flood Depth Grids and maps depicting the Areas of Expanded Risk (see samples below). Figure 6: Advisory Base Flood Elevation Release Areas and Map Book Examples: ABFE Maps, Flood Depth Grids and Areas of Expanded Risk GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

25 Local Data Availability - Corps Water Management Systems (CWMS) Modeling. In February 2015, the USACE completed a hydrologic modeling effort along the Guadalupe River and provided the results to both GBRA and FEMA for consideration. The USACE prepared the hydrologic and hydraulic modeling to generate a forecast model for the USACE reservoir, Canyon Dam. The model has allowed the USACE to manage the flood pool and calculate potential damages downstream of Canyon Dam prior to large flood flow releases. Following the flood events in late May 2015, FEMA refined the hydrologic analysis along the Blanco and San Marcos Rivers to develop and release ABFEs along stream reaches for communities to use in rebuilding and recovery efforts. Figure 7: CWMS Model Coverage, Figure 5: Guadalupe River Basin GBRA Mapping Activity Statement No. 1 (CTP-FRP-MAS-1). The GBRA continues its investigation into the area lakes (Dunlap, McQueeney, TP-4 and Nolte) built in the early 1930s for hydroelectgric generation. The lakes impound a relatively small volume of water in comparison to large flood events. Due to the relatively flat topography (very little change in elevation), this area is not suited for large, deep flood control reservoirs. These hydroelectric dams do not produce flood protection benefits. The GBRA requested a field survey near these hydroelectric dams for future model refinements. The residential structures in and around these dams are repeatedly inundated, and a number of severe repetitive loss properties are included in the inventory surrounding these structures. The work schedule for this project was impeded by the events in October GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

26 Figure 8: Availability of High-Quality Ground Elevation. FEMA s data availability review indicated that highquality ground elevation data was available for the majority of the basin. This data provides a great basis for preparing hydrologic and hydraulic modeling. The source and date of the LiDAR topographic data coverage is included in Figure 9. The TWDB Texas Natural Resource Information System, the Capital Area Council of Governments, the Lower Colorado River Authority, and FEMA have also collected ground elevation data. The basin data was collected between 2006 and FEMA Investment (2016). FEMA collected LiDAR data for a 606-square-mile area in and around DeWitt County, Texas, in spring 2015 to complete the LiDAR coverage of the watershed area. The ground elevation data collection effort was completed in summer Figure 9: Sources of LiDAR and Ground Elevation data Coordinated Needs Management Strategy Database Review. The CNMS database indicates the validity of FEMA s flood hazard inventory. Streams that are indicated as Unverified or Unknown in the database indicate that the information used to map the floodplains currently shown on the FIRM is inaccessible or that a complete evaluation of the critical and secondary CNMS elements could not be performed: The Guadalupe-Blanco basin stream coverage is not homogenous across the counties that intersect the basin. The hydrologic and hydraulic analysis behind the majority of the basin s flood hazard information is older and in need of an update. Figure 10: Flood Hazard Inventory, Guadalupe Blanco River Basin The current data inventory for streams in the four HUC8 sub-basins is approximately 5,000 stream-miles. Of this mileage, 660 is considered valid, having passed the seven critical element reviews and the ten secondary element reviews that had been completed. As the remaining mileage is a mixture of unverified and unknown mileage, more than 85 percent of the existing inventory may require further review. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

27 Unmapped Stream Coverage. FEMA also reviewed the current stream coverage and reviewed the areas against the National Hydrography Dataset (NHD). The NHD medium-resolution data inventoried by the USGS maps created at a 1:100,000 scale was used to review the watercourses within the HUC8s of concern. Population centers of 1,000 or more were reviewed for additional mileage against the highresolution data inventoried by the USGS Quadrangle maps created at a 1:24,000 scale. The intent of this review was to identify streams and watercourses and create a complete stream network for preparing Base-Level Engineering data. Base-Level Engineering After reviewing the four HUC8 sub-basins, FEMA approached the TWDB and the GBRA to coordinate on an innovative investment approach called Base-Level Engineering. This approach prepares multi-profile hydrologic (how much water) and hydraulic (how is water conveyed in existing drainage) data for a large stream network or river basin to generate floodplain and other flood risk information for the basin area. Base-Level Engineering provides an opportunity for FEMA to produce and provide non-regulatory flood risk information for a large watershed area in a much shorter period of time. The data prepared through Base-Level Engineering provides planning-level data that is prepared to meet FEMA s Standards for Floodplain Mapping. FEMA Investment (2016). In Fiscal Year 2016, FEMA initiated Base-Level Engineering for the four HUC8 sub-basins that make up the Guadalupe-Blanco River Basin. Figure 11 shows the network of streams that is being analyzed using the Base-Level Engineering approach. The Base-Level Engineering will provide the following items for use in the Guadalupe-Blanco River Basin: Hydrology modeling (regression) flow values for the 10-, 4-, 2-, 1- and 0.2-percent-annualchance storm events Hydraulic (HEC-RAS) modeling for all study streams 10-, 1-, and 0.2-percentannual-chance floodplain boundaries 1- and 0.2-percentannual-chance Water Surface Elevation Grids 1- and 0.2-percentannual-chance Flood Depth Grids Hazus flood analysis for the watershed Figure 11: Base-Level Engineering Study Streams, Guadalupe Blanco River Basin GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

28 Point file indicating the location of culverts and inline structures that may be informed by local asbuilt information The Base-Level Engineering approach will prepare flood hazard information for approximately 6,600 miles, thus adding over 1,600 stream-miles of supplementary flood hazard information for communities throughout the basin. Once completed, the Base-Level Engineering information will be provided to the communities throughout the basin for planning, risk communication, floodplain management, and permitting activities. CNMS Validation and Assessment. FEMA will compare the Base-Level Engineering results to the current flood hazard inventory identified in the CNMS database. This assessment will allow FEMA to compare this updated flood hazard information to the current effective floodplain mapping throughout the basin. The Base-Level Engineering information will be available in late Community Coordination. FEMA will share the Base-Level Engineering results (once complete) with communities throughout the basin. Communities will be provided the information, workshops, and training to support the use of Base-Level Engineering for planning, floodplain management, permitting, and risk communication activities. FEMA and the GBRA will work with communities to review, interpret and incorporate the Base-Level Engineering information into their daily and future community management and planning activities. Follow-On Phase Project Decisions. The Base-Level Engineering results and the current inventory will be compared to identify any areas of significant change. If the results show large areas of change (expansions and contractions of the floodplain, increases and decreases of the computed BFEs, and increases in expected flow values) FEMA will continue to coordinate with the communities to identify the streams that should be considered if the FIRMs are updated. To identify other streams for future refinement, community growth patterns and potential growth corridors should be discussed with FEMA. These areas of expected community growth and development may benefit from updated flood hazard information. Base-Level Engineering can be further refined to provide detailed study information for a FIRM update. Areas of communities that were developed prior to 1970 (pre-firm areas) may include repetitive and severe repetitive loss properties. They may also be areas where re-development is likely to occur. Having updated flood hazard information before re-development and reconstruction activities take place may benefit communities by providing guidance to mitigate future risk. FEMA will work with communities following the delivery of Base-Level Engineering to identify a subset of stream studies to be updated and included on the FIRMs. Communities may wish to review these possible areas and provide feedback once the Base-Level Engineering data has been received. Local communities can also refine Base-Level Engineering information and submit it through the Letter of Map Revision (LOMR) process to revise the existing flood hazard information and maintain the FIRMs throughout their community. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

29 Phase One: Discovery The Guadalupe Blanco River Authority (GBRA) and has been working with communities throughout the basin to determine their flood concerns and risks over a number of recent years. Efforts and information previously compiled by the GBRA and other active organizations provide a well rounded understanding of potential project work within this River Basin, made up of four HUC8s (Upper Guadalupe, Middle Guadalupe, Lower Guadalupe and San Marcos) GBRA s numerous efforts within these basins related to hazard mitigation planning, hydrologic and hydraulic investigations, flood risk studies and identification, flood risk assessment and flood risk reduction projects throughout the Guadalupe River basin are being compiled as a part of the feasibility study being completed by GBRA with assistance from the Texas Water Development Board (TWDB) and the US Army Corp of Engineers (USACE). FEMA has been in coordination with the GBRA since 2011 to discuss the needs for updated flood information throughout the river basin. During the planning phase of a watershed flood study for the more rural communities in the Lower Guadalupe River basin, the GBRA met with the seven counties and twelve incorporated communities within the lower reaches to discuss the regional project to determine flood hazard information for the lower basin, receiving unilateral support for the feasibility project. In the Fall of 2014, GBRA and FEMA Region 6 office began discussions to review the data available in order to request an exception for the Discovery effort. Given the number of active partners in the basin, the feasibility study and the on-going efforts to update local hazard mitigation plans, FEMA HQ agreed that the efforts undertaken by the GBRA to compile all available data to meet the data collection and meeting requirements outlined in FIMA Policy , Standards for Flood Risk Projects. In early 2015, FEMA and the GBRA met with the USACE-Fort Worth District to overview the Corps Water Management System (CWMS) modeling being prepared for the Guadalupe River south of Canyon Dam that is operated by the USACE. GBRA and USACE have been in coordination to review and utilize the resultant hydrologic findings in the feasibility study. FEMA Region 6 received approval for the Program Standard from FEMA HQ in September 2015 allowing the project to leapfrog Discovery effort outlined in FIMA Policy , Standards for Flood Risk Projects based on the efforts throughout the basin that exceed the requirements of the Discovery Effort. Due to the communication and information previously compiled by the GBRA and other active organizations throughout recent years, the collaborations and data collection exceed the requirements of the Discovery phase as outlined in the Standards for Flood Risk Projects and is currently in Phase 2, Risk Assessment and Communications. Figure 12: GBRA Flood Protection Planning Grant, Study Streams GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

30 Advisory Base Flood Elevations (ABFE) Mapping Effort. Immediately following the Memorial Day 2015 flooding event, FEMA reviewed the stream studies prepared by the City of San Marcos for their Master Plan and by the Guadalupe Blanco River Authority through the Flood Protection Planning grants. The FEMA review indicated that the updated information showed significant increases along Cypress Creek, Blanco, San Marcos and Guadalupe Rivers. Significant increases were also seen along streams throughout the City of San Marcos. The stream studies did not meet one FEMA standard, SID 5 that states No flooding source will receive a lower level of regulatory flood map product than what currently exists on effective maps. The Flood Protection Planning Grant study was not prepared to replace the FIRM information, the mileage requires the preparation of a regulatory floodway model run in order to update the FIRMs. FEMA Investment Decision (2016). The modeling for the floodway will be prepared in the Risk Identification and Assessment, Phase Two effort. Future Investments for Refinement FEMA will work closely with communities to identify additional areas for model refinement and FIRM panel updates. Once the Base Level Engineering information is prepared and released to communities, FEMA will coordinate with watershed communities and the Guadalupe Blanco River Authority to identify additional areas for future investment. Phase Two: Risk Identification and Assessment During the Risk Identification and Assessment Phase of a project, engineering modeling and analysis is refined to further enhance the identification of flood risk. Existing modeling may be updated using a more detailed methodology for calculating the amount of water (hydrology) expected during a storm event, plus additional detail and gage analysis. Hydraulic models could include additional refinement to the cross sections and stream X S XS X S Figure 13: Hydraulic Cross-Section crossings that may restrict flow in larger events, and the channel and structure information in existing models could be improved based on field surveys. WSE XS Engineering modeling applies the flow volume calculated for a certain storm interval and places that water into the natural channel described in the hydraulic Figure 14: Floodplain Mapping of Peak Water Surface Elevation GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

31 software. As tributaries and other drainage features are added to the main stream, the flow volume increases downstream. The modeling calculates the peak water-surface elevation determined at each cross section, and these peak values are graphically described in a profile. The peak values are then mapped on ground elevation information to produce a floodplain delineation that identifies the expected flood extent during the analyzed storm event. Once this hydrologic and hydraulic information is prepared, the models are used to produce a range of flood risk datasets that describe the variability of flooding within the delineated floodplain. These flood risk datasets include: Water Surface Elevation Grid - This 2D grid describes the water-surface elevation and profile for the length of the study area. Interpolated values are produced between each analysis cross section. Flood Depth Grid This grid provides an estimated flood depth at any location within the floodplain, allowing the variability of flood depth to be better represented for the stream channel and the floodplain areas. Annual Percent Chance Grid This grid is produced using statistical analysis to describe multiple percentages of the chance of flooding within the determined floodplain. 30-Year Percent Chance Grid Further statistical methodology is used to determine the percent chance of flooding within a 30-year window. The 30-year window was chosen as a 30-year period is common for home mortgages. Changes Since Last FIRM This polygon file identifies each location where modifications are identified by the revised and updated hydrologic and hydraulic analysis. Areas where floodplain widths increase/decrease, areas where floodway widths increase/decrease, and areas where flood zones have been modified are identifiable within this layer. The Physical Map Revision (PMR) is currently in this phase. During this phase, FEMA and its mapping partners benefit greatly from interaction and coordination with local technical and operations staff, which provides an opportunity to engage local knowledge as the modeling is prepared. FEMA would like to work closely with communities to identify areas where the modeling and floodplain mapping may not agree with on-the-ground accounts of flooding equivalent to the 1-percent-annual-chance storm event. FEMA would like to use this phase to review community comments and include any available technical information prior to updating the regulatory products (FIRM, FIS report, and DFIRM database). Flood Hazard Refinement Following the storm events in May 2015, FEMA and the communities identified refinements that would accomplish the following: Provide more detailed input information for stream crossings that had not been surveyed during the GBRA or City of San Marcos analysis; Include the 2015 storm events in the historical analysis record; Analyze additional sub-basins and include new gage locations in the hydrologic analysis; and GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

32 Prepare floodway analyses for selected streams. These model enhancements were necessary to meet FEMA s Standards for Flood Risk Projects 4 and provide the detail requested by the affected communities. Field Reconnaissance and Survey: Flow volumes following the October 2015 storm required the field survey to be delayed until February Field teams performed surveys in the vicinity of 33 stream crossings and structures along the 212 miles of stream refined in this phase. The field survey information was Figure 15: Structure Survey Locations, PMR Study area used to refine the stream inverts, top-of-road profiles, road abutments, low chord information, and culvert sizes for these structures within the study area. Additionally, a few Natural Resourced Conservation Services inline reservoir structures were updated with field measurements to provide more detailed input information for the hydraulic analysis. Refined Hydrologic Modeling: The Interagency Flood Risk Management (InFRM) team, which includes subject matter experts from the USACE, the USGS, and the National Weather Service, used several different methods, including statistical hydrology and rainfall-runoff watershed modeling, to calculate the 100-year flow. These various flow calculations were compared against each other to produce 100- year flow values that are consistent and defendable across the basin. Both up-to-date statistical analysis and state-of-the-art rainfall-runoff watershed modeling were used to estimate the 100-year flow values throughout the river basin. In the statistical analysis, the gage records were updated through the year 2016 to include all of the recent major flood events. However, since statistical estimates change with each additional year of data, their results were compared to the results of a detailed watershed model, which is less likely to change over time. A watershed model was built for the river basin with input parameters that represented the physical characteristics of the watershed. After building the model, the InFRM team made an extensive effort to calibrate the model and to verify that it accurately simulated the response of the watershed to a range of observed flood events, including large events similar to a 100-year flood. Eight recent storm events were used to fine-tune the model. 4 SID 5 notes, no flooding source will receive a lower level of regulatory flood map product than what currently exists on effective maps. A number of streams required a floodway run to be prepared to replace the current effective FIRM information. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

33 The InFRM report is still being completed, but the hydrologic analysis was compiled and presented to the affected communities as the analysis was being prepared. Refined Hydraulic Modeling: The hydraulic modeling was refined to include the field survey information collected and incorporate the updated hydrologic modeling and calculated flow change locations. In select areas, floodway model runs were also prepared. Floodway models are prepared to review the effect that fill or encroachment may have along a stream. Floodplain and floodway evaluations are the basis for floodplain management programs. As fill is placed in floodplains, the area available to storm flows becomes constricted. The evaluation of the impact of floodplain encroachments on the expected water-surface profiles can be of substantial interest to planners, land developers, and engineers. A floodway is defined as the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water-surface elevation by more than a designated height. The base flood relates to the 1-percent-annual-chance event, and the designated height is 1 foot, but State or local communities may establish a more stringent regulation for maximum rise. The floodway is usually determined by an encroachment analysis, which determines the limits of encroachment (such as fill) that will cause a specified rise in water-surface elevation, in this case a 1.0-foot increase. For the purposes of floodway analysis, the floodway fringe is assumed to be completely blocked, and the floodway is the remaining portion of the floodplain where the 1- percent-annual-chance floodwaters can flow without raising the water surface more than the targeted increase. Over 200 stream-miles will be refined in Phase 2 Figure 16: Floodway Definition Sketch efforts, which will update the flood hazard information for the Guadalupe, San Marcos, and Blanco Rivers, as well as a number of tributaries within Hays County, and replace the information between the Blanco County line and the confluence of the San Marcos River with the Guadalupe River. The streams being refined are indicated in Figure 16. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

34 Figure 17: Study Streams, Phase 2 Physical Map Revision The study mileage delivery has been broken into four phases to allow communities a chance to review the analysis and results in advance of the Flood Risk Review meeting. The delivery areas are as follows: Delivery Delivery Area Updated Streams 1 City of San Marcos, Hays County 2 3 City of Wimberley, City of Woodcreek, Comal and Hays Counties City of San Marcos, City of Luling, City of Martindale, and City of Staples, Caldwell, Guadalupe, Gonzales, and Hays Counties 4 Gonzales, and Hays Counties Sink Creek, Purgatory Creek, and Cottonwood Creek Blanco River (above City of San Marcos boundary upstream to Blanco County line), and Cypress Creek Blanco River (City of San Marcos) and San Marcos River (City of San Marcos to City of Gonzales) Cypress Tributaries (Hays County) and San Marcos River (Hays and Gonzales) Delivery Schedule June 2016 May 2016 September 2016 October 2016 Community Collaboration FEMA initiated this refinement effort with a number of face-to-face meetings, one community at a time. Individual project kick-off meetings were held in late November and early December 2015 with each of GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

35 the following communities: the cities of Luling, San Marcos, Wimberley, Martindale, Staples and Woodcreek, and Caldwell, Comal, Guadalupe, Gonzales, and Hays Counties. FEMA staff, community leaders, and local technical staff met to review the project scope and the expected project timeline for the modeling refinement work. During these kick-off meetings, FEMA asked the communities to provide any available data and requested the following items to support modeling calibration and mapping efforts: high water marks; elevation, survey or other topographic datasets; and digital community boundaries. During these community meetings, FEMA discussed having monthly touchpoint meetings with community officials and technical staff to coordinate as each step of the analysis and mapping effort was completed. FEMA established these monthly coordination calls to consult communities throughout the modeling effort. As delivery areas neared completion, the coordination call was used to communicate and review the areas where floodplains had been modified from the previously released advisory flood hazard data. FEMA and its technical teams benefited greatly from the community involvement and engagement during these conference calls and webinars, allowing the project schedule adjustments and areas of change to be openly communicated and shared with the communities in the areas being updated. Flood Risk Review Meeting Flood Risk Review Meetings are scheduled for late September and October The first formal sharing of the modeling and mapping updates occurs at the Flood Risk Review Meeting. At this meeting, FEMA intends to continue community coordination efforts and discussions with a variety of watershed partners to review the effects of physical and meteorological changes within the project area. The FEMA team remains focused on reviewing the identification of flood and other natural hazard risks, areas where modifications in the flood delineations have been identified, and changes in risk assessment, working with community and technical staff throughout the analysis/assessment processes. The team will deliver the Phase Two (Data and Engineering) data for the PMR: Hydrological Analysis Hydraulic Analysis Resultant Floodplain Mapping The objectives of the Flood Risk Review meeting include: Promote local buy-in of analysis/study results Review Risk Identification (engineering) results with local communities Review the hazard mitigation plan, compared to the study findings Identify risk communication needs and options Support identified community-driven mitigation actions Identify and/or resolve community comments and appeals before the regulatory products are issued GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

36 Solicit community input on results and promote buy-in of analyses prior to moving forward Continue developing relationships with communities The new analysis and products will be delivered to communities in advance of this meeting, so communities will have the chance to review and assess the modeling and mapping results prior to the in-person meeting. FEMA would like to work with communities at each project milestone to identify and address any technical concerns with the modeling results. Because this phase of the timeline is less rigid than the statutory and regulatory timelines in Phase Three, FEMA can work more closely and intimately with the communities to review and address their concerns. Next Steps Once the analysis is completed, FEMA will review the areas of change before determining if a project will move forward to update the regulatory products (FIS report, FIRM, and DFIRM database). A cursory review of the modeling results indicates that this study area has significant changes in floodplain width and depth. Based on their review of the ABFE information, communities have indicated that they believe the current flood hazard information needs to be updated to reflect these changes. All communities will be provided a chance to review the engineering and mapping to identify areas about which they have further questions or technical inquiries. FEMA will work with communities after delivering the hydrologic and hydraulic analysis and floodplain work maps to collect any outstanding technical inquiries within the study area. After coordinating with communities, FEMA will likely initiate the Phase Three effort to update the regulatory products. Potential Community Activities The availability of updated flood risk information provides the community a chance to review a range of possible actions that may be taken. Some possible community activities are identified below for consideration: Local Hazard Mitigation Plan (Hazard Profile): The updated flood risk information provides an opportunity to review local hazard mitigation plans. The flood risk profile, hazard extent, and vulnerability assessment may be refined based on the Changes Since Last FIRM, water surface elevation grids, flood depth grids, and percent annual chance grids. Communities should reconvene their Mitigation Plan Steering Committee to identify how these narrative sections should be refined with the additional information. Local Hazard Mitigation Plan (Mitigation Strategies): Communities may review community assets, critical facilities and other vulnerable areas within a community to identify or refine the mitigation strategies and locate future mitigation projects to reduce long-term natural hazard risk throughout the community. FEMA s publication Mitigation Ideas: A Local hazard mitigation plans help to: Protect public safety Prevent damage to community assets Reduce costs of disaster response and recovery Improve community capabilities Create safer, more sustainable development GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

37 Resource for Reducing Risk to Natural Hazards ( may provide some strategies and projects for the local Mitigation Plan Steering Committee to review. Mitigation Project Scope Preparation: Each year, communities may apply for various FEMA Hazard Mitigation Assistance (HMA) grants available for implementing mitigation actions. Communities may review their critical mitigation needs and opt to prepare project submittals for one of the grant opportunities FEMA offers. These HMA Grant Programs are managed by the State of Texas (grantee), which has the primary responsibility for selecting and administering the mitigation activities throughout the State. Individuals are not eligible to apply directly for HMA funds; however, communities may act as an eligible applicant or sub-applicant to apply for funding on behalf of individuals. For specific information on available HMA grant funding and current project priorities within Texas, please contact the appropriate State agency. FMA Grant Program Texas Water Development Board (TWDB) Kathy Hopkins (512) HMGP or PDM Grant Programs Texas Division of Emergency Management (TDEM) Paula Logan (512) Community Rating System (CRS): The NFIP s CRS is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Communities interested in the CRS program may contact Mark Lujan, FEMA Region 6 CRS Coordinator, by phone at (940) or via at mark.lujan@fema.dhs.gov. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

38 Adoption of Higher Standards: Community participation in the NFIP is voluntary. When a community joins the NFIP, a community must ensure that their adopted floodplain management ordinance and enforcement procedures meet NFIP requirements. NFIP minimum requirements include requiring permits for all development in the SFHA and ensuring that the construction materials and methods used will minimize future flood damage. Higher standards, such as freeboard, land use and zoning practices, and other approaches, allow communities to minimize future damages within the community by using more restrictive building codes and requirements. Risk Reduction Activities: The NFIP s Community Rating System Coordinator s Manual identifies a number of activities that communities can undertake to reduce their long-term risk. Higher standards, land use planning, future conditions modeling, and other approaches are available for consideration. Severe Repetitive Loss (SRL) Strategy: The primary objective of the SRL properties strategy is to eliminate or reduce the damage to residential property and the disruption to life caused by repeated flooding. The SRL Grant Program makes funding available for a variety of flood mitigation activities. Under this program, FEMA provides funds to State and local governments to assist NFIP-insured SRL residential property owners with mitigation projects that reduce future flood losses. Projects could include acquisition or relocation of at-risk structures and conversion of the property to open space, elevation of existing structures, or dry floodproofing for historic properties. Public Risk Awareness and Outreach Campaigns: Communities may use the new and existing flood hazard information to develop a public information and outreach campaign for their community. Since 2010, FEMA has conducted an annual nationwide study of flood risk awareness among U.S. households. Participants overwhelmingly responded that they expect and trust flood risk information when it comes from local community officials and staff. FEMA Region 6 has also developed the Risk Communication Guidebook for Local Officials ( which identifies a number of local communication activities. The Guidebook provides tools, templates, and resources for communities interested in developing a local outreach campaign; it is presented by Risk MAP project phases, similar to this report. The CRS Coordinators Manual and the CRS Resources website (for Activity 300, available at can provide additional information for communities interested in local flood hazard and risk awareness outreach campaigns. High Water Mark (HWM) Initiative: As part of the NFIP, the HWM Initiative is a community-based program that increases residents awareness of flood risk and encourages action to mitigate that risk. As part of the project, communities post HWM signs in prominent places, hold a high-profile launch event to Figure 18: High Water Mark Sign Unveiling, City of Leon Valley, Texas, January 2016 GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

39 unveil the signs, conduct ongoing education to build local awareness of flood risk, and complete mitigation actions to build community resilience against future flooding. The initiative has a variety of audiences, such as local officials, emergency management personnel, and community leaders, as well as FEMA Regions and Federal, State, and local entities. More information on the HWM Initiative is available on the FEMA website at Phase Three: Regulatory Product Update During the Regulatory Product Update phase of a Flood Risk Project, the results produced in the previous phase are used to prepare and produce three regulatory products in a countywide manner. This phase of the project is more regimented than previous phases, as it includes some statutory and regulatory timelines that must be adhered to by FEMA and the communities involved in the update areas. FEMA will remain in contact with communities throughout the process. Flood Insurance Study Report The engineering analysis results are used to update existing countywide FIS reports. The narratives within the FIS reports are updated to include specifics about the latest analysis and study effort within each county. Additionally, the Floodway Data Tables and Water Surface Elevations that provide look-up information to community staff in their administration of the program are also updated to provide the most up-to-date information to the public and communities. Flood Insurance Rate Map Panels The flood hazard data (floodplains, floodways, and zone designations) would be updated on 58 FIRM panels for five counties: Caldwell, Comal, Gonzales, Guadalupe, and Hays. The Cities of Luling, Martindale, San Marcos, Staples, Wimberley, and Woodcreek are included on these panels, and FEMA will also coordinate with them before deciding to prepare Preliminary FIRMs. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

40 Figure 19: Physical Map Revision - 58 panels The revised FIRM data is based on a combination of new and existing engineering analyses of floodplain boundaries. Detailed studies are mapped with a flood zone designation of Zone AE. All mileage studied by detailed methods produces a FIRM that includes Base Flood Elevations (BFEs). As previously described under Phase Two, studies of this nature include field surveys, hydraulic structures, modeling calibration, and multiple flood frequency profiles that will be published in the FIS report. Some detailed mileage also includes a regulatory floodway. Floodway models are prepared to review the effect that fill or encroachment may have along a stream. Floodplain and floodway evaluations are the basis for community floodplain management programs. More information on floodway modeling is available in the Phase Two section of this report. The remaining mileage that is included on the 58 FIRM panels to be updated would be merged into the new FIRMs using of the existing DFIRM database previously prepared for the five affected counties. DFIRM Database Communities receive an updated and standardized DFIRM database, which is a digital version of the FIRM, designed for use with GIS software. The DFIRM database is designed to provide communities with the ability to determine the flood zone, BFE, and floodway status for a particular location using their own internal GIS staff. The DFIRM database also includes data related to the NFIP community, FIRM GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

41 panels, analysis cross sections, and hydraulic structure information, as well as base map information such as roads and stream data for reference and local use. Letters of Map Change As part of the DFIRM update, the project team will review all LOMAs and LOMRs and determine, for each case, whether to incorporate, revalidate/reissue, or supersede the LOMAs and LOMRs, based on technical data. The following LOMRs have been reviewed and categorized: Case Number P P Stream Name(s) & Community(ies) Stone Creek Crossing (City of San Marcos) Retreat on Willow Creek (Hays County and City of San Marcos) Effective Date August 5, 2015 May 18, 2016 Category Incorporated, field-surveyed cross-sections and structure geometry used in detailed model Incorporated, field-surveyed cross-sections and structure geometry used in detailed model Communities should be advised that ALL LOMAs will be included in the Preliminary Summary of Map Actions (SOMA) provided when the preliminary FIRM panels and FIS reports are released. Communities should review their map repositories for any LOMA or LOMR within the stream areas being studied. These community files may provide additional information for historic map revisions that will assist in the review of the cases for incorporation. Next Step: Preliminary Issuance Once FEMA has received, reviewed, and responded to all comments and technical data received as a result of the Flood Risk Review meeting, FEMA will prepare the preliminary FIRMs, FIS report, and DFIRM database for release. The Preliminary products will be sent to the community CEOs and FPAs for an initial review. (These will also be available for public review on FEMA s Flood Map Service Center: Preliminary issuance for the Physical Map Revision is currently targeted for January Steps after the Preliminary Issuance The post-preliminary process is initiated with the preliminary issuance of the FIRM, FIS report, and DFIRM database. The activities that will occur during this period are highlighted in Figure 19. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

42 FEMA issues Preliminary FIRMs to communities Preliminary Data becomes available on interactive Preliminary Site Preliminary FIRM panels, FIS text, and DFIRM database are available on the Map Service Center (MSC) FEMA holds (final) CCO meeting with communities (as appropriate) FEMA issues Proposed BFE Determination, Letter to CEO and publishes Proposed BFEs in Federal Register and local newspaper Community reviews FEMA appeal/comment resolution FEMA reviews and addresses appeals/comments received Community submits appeal/comment to FEMA OR Community submits letter indicating no appeal/comment will be submitted 90-day Appeal Period starts FEMA issues Letter of Final Determination (LFD) to CEO and FPA and publishes FInal Rule in Federal Register FEMA prepares final FIS, FIRM, DFIRM database for delivery to the MSC Pending data is posted on the MSC Community enacts required ordinances, notifies FEMA and State FIS, FIRM, and DFIRM database become effective. Community enters/remains in NFIP Figure 20: Post Preliminary Process Additional information is provided for the immediate steps following preliminary issuance to provide some overview to communities prior to these activities being initiated. Preliminary Data Available through Interactive Website. 30 Day Community Review Period. For FIRMs that are based on FEMA-contracted studies/mapping projects, communities have an initial review period, which generally lasts 30 days. Consultation Coordination Officer (CCO) Meeting. Following the informal review of the preliminary information, FEMA holds a more formal community coordination meeting during which community officials meet with FEMA representatives. 90-Day Appeal and Comment Period Initiated: Following the CCO meeting, FEMA will issue a letter to the community s Chief Executive Officer and Floodplain Administrator to inform them that FEMA is moving toward the initiation of the appeal period. FEMA will work internally to publish the Proposed BFE Determination in the Federal Register and then will publish two notices in local newspapers. The letter will indicate the publication date for the notice in the Federal Register and the two publication dates for the local newspapers. The appeal and comment period is initiated after the second local print date and is 90 calendar days long. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

43 During this period, community officials or residents may appeal the proposed BFEs and/or base flood depths based on scientific or technical data. Community officials or individuals also may submit requests for changes to other information shown on the DFIRM flood zone boundaries, regulatory floodway boundaries, road names and configurations during the appeal period. Communities are responsible for the collection, review and approval of appeals that are submitted during the 90-day appeal period. An appeal is a formal objection to proposed new or modified BFEs or base flood depths. Appeals must be submitted through a community official, and can be submitted on behalf of owners or lessee s of real property within the community s jurisdiction. All appeals must be submitted with the statutory 90-day appeal period and must be based on data that shows the proposed or proposed modified BFEs are scientifically or technically incorrect. A comment is an objection to or comment on any information, other than proposed BFEs or base flood depths, shown on an NFIP map that is submitted by community officials or interested citizens through the community officials during the 90-day appeal period. Comments usually involve changes to items such as road locations and road names, corporate limits updates, or other base map features. The appeal resolution occurs after all appeals and comments are received during the statutory 90-day Appeal Period. FEMA determines the validity of the appeal and provides the associated community and all appellants an appeal resolution letter. After the Appeal Period, FEMA will send community leaders a Letter of Final Determination (LFD) stating that the preliminary FIRM will become effective in six months. The letter also discusses the actions each affected community participating in the NFIP must take to remain in good standing in the NFIP. After the preceding steps are complete and the six-month compliance period ends, the FIRMs are considered effective maps and new building and flood insurance requirements become effective. Future Physical Map Revisions The release of the maps in these areas does not identify the end of coordination between the local community and FEMA. Local communities should continue their local floodplain management activities and submit LOMRs when local development alters the flood hazard in the community. Communities may work with the GBRA to identify additional areas for detailed study or refined analysis and mapping through the Physical Map Revision process. These project requests should be documented and submitted to through the local Cooperating Technical Partner, GBRA, and the State CTP, the TWDB, for consideration and prioritization. FEMA works with the local and State CTPs throughout Texas and the Region to identify and plan for future analysis and mapping projects. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

44 Appendix I: Community-Specific Reports Communities CALDWELL COUNTY LULING MARTINDALE COMAL COUNTY GUADALUPE COUNTY HAYS COUNTY STAPLES SAN MARCOS WIMBERLEY WOODCREEK GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

45 CALDWELL COUNTY KNOW YOUR RISK 133 sq. miles of the county is in the PMR study area 17, 802 Population based on 2010 census 21.3% expected population growth from claims for structures repeatedly damaged by flood 27.4% of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles Stream Miles Detail Studied 8.8% 7 Flood-related presidential disaster declarations in your county $2.6M in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

46 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Your Hazard Mitigation Plan is set to expire December 6, FEMA s Hazard Mitigation Grant Program and Pre-Disaster Mitigation funding may allow costs associated with power supply back-up generators if they are for continued use of critical facilities during times of disaster. The benefit to cost analysis accompanying the grant application should include consideration of needed equipment. Read more about the FEMA Hazard Mitigation Assistance grant programs on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. The hazard mitigation goals identified projects for : Acquire and install portable generators for critical facilities. Develop CWPP. Develop a public awareness program to promote Turn Around, Don t Drown Community Wildfire Protection Plans (CWPPs) are a mechanism for communities to address their wildfire risk. These plans promote collaboration and local action to prioritize fuel reduction and reduction of wildfire risk to structures. Visit the Texas A&M Forest Service CWPP 2 site for more information. Communities should work with their local National Weather service office to promote use of the Turn Around, Don t Drown materials and signs. The regional NWS office supporting the county of Caldwell is located in Fort Worth. Contact details and additional information is located on the NWS website

47 CITY OF LULING KNOW YOUR RISK 5.6 sq. miles of the community is in the PMR study area 5,411 Population based on 2010 census 6.6% expected population growth from claims for structures damaged by flood 19.4% Stream Miles Detail Studied 7 $239K of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in flood-related losses KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

48 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Public awareness programs on dangers of flooding are eligible projects under FEMA s Hazard Mitigation Assistance program grants. Read more about the FEMA Hazard Mitigation Assistance program grants on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire December 6, The hazard mitigation goals identified projects for: Public awareness programs. Develop wildfire recovery plan. Permitting in compliance with NFIP. Evacuation planning for urban areas. Community Wildfire Protection Plans (CWPPs) are a mechanism for communities to address their wildfire risk. These plans promote collaboration and local action to prioritize fuel reduction and reduction of wildfire risk to structures. Visit the Texas A&M Forest Service CWPP 2 site for more information. FEMA s E273 Managing the Floodplain Through the NFIP course is designed to provide an organized training opportunity administering local floodplain management ordinance. The course focuses on the NFIP and concepts of floodplain management, maps and studies, ordinance administration, and the relationship between floodplain management and flood insurance. Visit the Texas Floodplain Management Association (TFMA) 3 website to determine dates and locations of upcoming field deployed versions of Course E273 or other floodplain management workshops. Overseeing regional response and evacuation plans throughout the state, the TDEM offers a wide variety of emergency management training courses and resources to support higher levels of preparedness. Financial and technical assistance to further develop emergency plans to minimize exposure to future hazards are eligible for funding under Federal and State grants. Visit the Grants and Resources 4 page on the TDEM website for more information

49 CITY OF MARTINDALE KNOW YOUR RISK 2.0 sq. miles of the community is in the PMR study area 1,116 Population based on 2010 census 17.7% expected population growth from claims for structures repeatedly damaged by flood 61.8% Stream Miles Detail Studied 7 $211K of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

50 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Your Hazard Mitigation Plan is set to expire July 12, Green Infrastructure has become a cost-effective approach for flood loss avoidance in Stormwater Management. It reduces and treats stormwater at its source while delivering environmental, social and economic benefits. The U.S. Environmental Protection Agency 1 website offers more information on development and funding. The hazard mitigation goals identified projects for: Design, engineering and installation of drainage utility infrastructure to minimize or reduce the impact of stormwater. Establish a wildfire management plan. Community Wildfire Protection Plans (CWPPs) are a mechanism for communities to address their wildfire risk. These plans promote collaboration and local action to prioritize fuel reduction and reduction of wildfire risk to structures. Visit the Texas A&M Forest Service CWPP 2 site for more information

51 COMAL COUNTY KNOW YOUR RISK 16.6 sq. miles of the county is in the PMR study area 51,835 Population based on 2010 census 45.9% expected population growth from claims for structures repeatedly damaged by flood 0.1% Stream Miles Detail Studied 6 $6.9M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

52 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Your Hazard Mitigation Plan is set to expire November 28, The hazard mitigation goals identified projects for : Removal of vegetation and flood debris from channels. Flood-risk reduction and acquisition of flood-prone properties. Automated water crossing alert systems. Hazard mapping and analysis of sinkholes. The U.S. Army Corps of Engineers (USACE) can assist local government or non-government organizations with water and related land resources studies or projects. Cost-share programs may be available to investigate potential flood risk management issues that might fit the Corps Continuing Authorities program to proceed with a feasibility study. Flood risk management studies and projects, including the Continuing Authorities Program, are managed by the Corps Districts. View details on the USACE Frequently Asked Questions webpage under finding federal grant information. Contact the U.S. Army Engineer District office in Fort Worth to discuss projects involving the clearing and snagging of waterways. Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Public warning or notification systems may be fundable under FEMA s 5-percent initiative within the Hazard Mitigation Grant Program grant. The 5-percent initiative is utilized for projects for which it may be difficult to conduct a standard benefit to cost analysis to ensure cost-effectiveness. Hazard analysis and mapping of various hazards, including sinkholes, may be eligible under FEMA s Hazard Mitigation Assistance Grants funding for mitigation plans. The benefit to cost analysis must include consideration of the mapping assessment Read more about the FEMA grants that provide financial assistance for mitigation projects and planning on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team

53 GUADALUPE COUNTY KNOW YOUR RISK 60.2 sq. miles of the county is in the PMR study area 47,427 Population based on 2010 census 28.5% expected population growth from claims for structures repeatedly damaged by flood 24.3% Stream Miles Detailed Studied 7 $44.3M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

54 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Read more about the FEMA Hazard Mitigation Assistance program grants on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire December 6, The hazard mitigation goals identified projects for: Flood-risk reduction and acquisition of flood-prone property. Streamflow monitoring. Investigate availability of funding development of dam inundation data. Adopt the No Adverse Impact policy. Monitoring river flows is a matter of public safety, environmental protection and wise economic development. WaterWatch is a U.S. Geological Survey (USGS) website that displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for local, State, and Federal needs. The USGS streamgaging network reports consistent results using standard techniques and technology. Visit the WaterWatch 2 website to learn more. Individual dam owners are required to create Emergency Action Plans In Texas, the Texas Commission on Environmental Quality s Dam Safety Program 3 monitors and regulates both private and public dams. As part of their requirements, dam owners must create a map of the estimated inundation zones. Working with the TCEQ can help to work with dam owners to develop this information. The No Adverse Impact (NAI) is a floodplain management principle to encourage property owner s actions to not adversely affect the rights of other property owners. Adopting the NAI approach results in reduced flood risk and promotes local accountability for development. Visit the Association of State Floodplain Manager s website 4 for more information on this approach

55 CITY OF STAPLES KNOW YOUR RISK 1.2 sq. miles of the community is in the PMR study area 267 Population based on 2010 census 50.5% expected population growth from claims in Guadalupe County for structures repeatedly damaged by flood 4.9% Stream Miles Detail Studied 7 $44.3M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive losses within the County KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

56 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program (HMGP), Pre-Disaster Mitigation (PDM), and Flood Mitigation Assistance (FMA) grants. HMGP assists in implementing long-term hazard mitigation planning and projects following a Presidential major disaster declaration. Project funding is generally 15% of the total amount of Federal assistance provided to a State following a major disaster declaration. Hazard Mitigation planning is up to 7% of the overall funding PDM provides funds for hazard mitigation planning and projects on an annual basis FMA provides funds for planning and projects to reduce or eliminate risk of flood damage to buildings that are insured under the National Flood Insurance Program (NFIP) on an annual basis A single or multi-jurisdictional hazard mitigation plan was not identified for the City of Staples. The amount of funding available depends on congressional appropriations to these programs each year. Most grants are awarded assuming a 25-percent non-federal contribution to cost share eligible mitigation activities. The mitigation team within the Texas Division of Emergency Management (TDEM) 1 maintains the State Hazard Mitigation Plan, review of local mitigation plans, and provides hazard mitigation training for community officials. TDEM s Mitigation staff manages a large number of the grant programs provide funding for cities, counties, and other governmental entities to carry out local and regional hazard mitigation projects and plans. To learn more about the FEMA Hazard Mitigation Assistance program grants, visit the Texas Division of Emergency Management (TDEM) 2 and view the grant program fact sheet. Opportunities can be discussed with the TDEM mitigation team

57 HAYS COUNTY KNOW YOUR RISK sq. miles of the county is in the PMR study area 68,834 Population based on 2010 census 55.1% expected population growth from claims for structures repeatedly damaged by flood 9.5% Stream Miles Detail Studied 8 $4.7M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

58 TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Read more about the FEMA Hazard Mitigation Assistance grant programs on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire December 6, The hazard mitigation goals identified projects for: Flood-risk reduction and acquisition of flood-prone properties. Streamflow monitoring. Higher floodplain management standards. Training and outreach. Monitoring river flows is a matter of public safety, environmental protection and wise economic development. WaterWatch is a U.S. Geological Survey (USGS) website that displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for local, State, and Federal needs. The USGS streamgaging network reports consistent results using standard techniques and technology. Visit the WaterWatch 2 website to learn more. Issued by the Association of State Floodplain Managers, the Guide to Higher Regulator Standards in Floodplain Management 3 describes stricter measures to minimize flooding impacts. Implementing higher development standards reduces the risk to life and displacement of residents, property and environment damage, and the burden on community infrastructure and services. The Texas Floodplain Management Association (TFMA) is currently revisiting higher regulatory standards to transform the national guidance into a document applicable for communities in Texas. Stay informed of the progress by visiting their website 4, or by reading the TFMA newsletter 5. The National Weather Service (NWS) StormReady 6 program uses a grassroots approach to recognize communities who demonstrate severe weather readiness and are better prepared for increasing vulnerability to extreme weather events. Visit the StormReady website to learn more

59 CITY OF SAN MARCOS KNOW YOUR RISK 28.8 sq. miles of the community is in the PMR study area 44,894 Population based on 2010 census 40.8% expected population growth from claims for structures repeatedly damaged by flood 31.3% Stream Miles Detail Studied 8 $9.1M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

60 TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Read more about the FEMA Hazard Mitigation Assistance program grants on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire November 28, The hazard mitigation goals identified projects for: Flood-risk reduction and acquisition of flood-prone properties. Streamflow monitoring. Higher floodplain management standards. Training and outreach. Monitoring river flows is a matter of public safety, environmental protection and wise economic development. WaterWatch is a U.S. Geological Survey (USGS) website that displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for local, State, and Federal needs. The USGS streamgaging network reports consistent results using standard techniques and technology. Visit the WaterWatch 2 website to learn more. Issued by the Association of State Floodplain Managers, the Guide to Higher Regulator Standards in Floodplain Management 3 describes stricter measures to minimize flooding impacts. Implementing higher development standards reduces the risk to life and displacement of residents, property and environment damage, and the burden on community infrastructure and services. The Texas Floodplain Management Association (TFMA) is currently revisiting higher regulatory standards to transform the national guidance into a document applicable for communities in Texas. Stay informed of the progress by visiting their website 4, or by reading the TFMA newsletter 5. The National Weather Service (NWS) StormReady 6 program uses a grassroots approach to recognize communities who demonstrate severe weather readiness and are better prepared for increasing vulnerability to extreme weather events. Visit the StormReady website to learn more

61 CITY OF WIMBERLEY KNOW YOUR RISK 8.7 sq. miles of the community is in the PMR study area 2,626 Population based on 2010 census 39.8% expected population growth from claims for structures repeatedly damaged by flood 20.5% Stream Miles Detail Studied 8 $1.8M of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

62 TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Read more about the FEMA Hazard Mitigation Assistance program grants on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire July 12, The hazard mitigation goals identified projects for: Flood-risk reduction and acquisition of flood-prone properties. Streamflow monitoring. Higher floodplain management standards. Training and outreach. Monitoring river flows is a matter of public safety, environmental protection and wise economic development. WaterWatch is a U.S. Geological Survey (USGS) website that displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for local, State, and Federal needs. The USGS streamgaging network reports consistent results using standard techniques and technology. Visit the WaterWatch 2 website to learn more. Issued by the Association of State Floodplain Managers, the Guide to Higher Regulator Standards in Floodplain Management 3 describes stricter measures to minimize flooding impacts. Implementing higher development standards reduces the risk to life and displacement of residents, property and environment damage, and the burden on community infrastructure and services. The Texas Floodplain Management Association (TFMA) is currently revisiting higher regulatory standards to transform the national guidance into a document applicable for communities in Texas. Stay informed of the progress by visiting their website 4, or by reading the TFMA newsletter 5. The National Weather Service (NWS) StormReady 6 program uses a grassroots approach to recognize communities who demonstrate severe weather readiness and are better prepared for increasing vulnerability to extreme weather events. Visit the StormReady website to learn more

63 CITY OF WOODCREEK KNOW YOUR RISK 1.3 sq. miles of the community is in the PMR study area 1,457 Population based on 2010 census 10.1% expected population growth from claims for structures repeatedly damaged by flood 12.3% Stream Miles Detail Studied 8 $257K of the area being studied is flood-prone during a 1% annual chance storm event Participating in the National Flood Insurance Program. CNMS Stream Miles % Flood-related presidential disaster declarations in your county in severe repetitive loss KEEPING COMMUNITIES INFORMED: Your Risk MAP Timeline YOU ARE HERE Discovery Project Kickoff Flood Risk Review Preliminary Map CCO Meeting Open House Appeal Period Letter of Issuance Final Determination Effective Maps

64 CITY OF WIMBERLEY TAKE ACTION: Potential Next Steps Localized flood-risk reduction structures and the acquisition of flood-prone properties are eligible projects under FEMA s Hazard Mitigation Grant Program, Pre-Disaster Mitigation, and Flood Mitigation Assistance grants. Read more about the FEMA Hazard Mitigation Assistance program grants on the Texas Division of Emergency Management (TDEM) 1 fact sheet. Opportunities can be discussed with the TDEM mitigation team. Your Hazard Mitigation Plan is set to expire July 12, The hazard mitigation goals identified projects for: Flood-risk reduction and acquisition of flood-prone property. Reduce wildfire risk. Higher floodplain management standards. Training and outreach. Community Wildfire Protection Plans (CWPPs) are a mechanism for communities to address their wildfire risk. These plans promote collaboration and local action to prioritize fuel reduction and reduction of wildfire risk to structures. For more information, visit the Texas A&M Forest Service CWPP website. Issued by the Association of State Floodplain Managers, the Guide to Higher Regulator Standards in Floodplain Management 3 describes stricter measures to minimize flooding impacts. Implementing higher development standards reduces the risk to life and displacement of residents, property and environment damage, and the burden on community infrastructure and services. The Texas Floodplain Management Association (TFMA) is currently revisiting higher regulatory standards to transform the national guidance into a document applicable for communities in Texas. Stay informed of the progress by visiting their website 4, or by reading the TFMA newsletter 5. The National Weather Service (NWS) StormReady 6 program uses a grassroots approach to recognize communities who demonstrate severe weather readiness and are better prepared for increasing vulnerability to extreme weather events. Visit the StormReady website to learn more

65 Appendix II: Mitigation Tactics What is Mitigation? Mitigation is the effort to reduce loss of life and property by lessening the impact of disasters. Hazard mitigation is any sustained action taken to reduce or eliminate long-term risk to life and property from hazards. For mitigation to be effective, a community must take action now before the next disaster to reduce human and financial consequences later. Communities should incorporate sustainable development concepts into their construction efforts, encourage both natural, non-structural solutions and structural measures, and communicate risk. Taking the opportunity to enforce additional measures through local ordinances and review processes influences the way land and buildings are developed and built: Comprehensive plans Land use ordinances Subdivision regulations Development review Building codes and enforcement NFIP Community Rating System Capital improvement programs Open space preservation Stormwater management regulations and master plans Communities can take action through structure and infrastructure modification measures: Elevate structures so the lowest floor and utilities are above the BFE Elevate and anchor mobile homes and discourage them from being located in the SFHA Install engineered flood vents or backflow valves to prevent damages from water flow during a flood Keep drains on property clear of debris to assist in the prevention of sewer backups Improve stormwater management and drainage system capacity Construct and maintain flood control structures Floodproof facilities for potable water and wastewater treatment Acquire repetitive loss properties in floodprone areas Risk communication and outreach programs can inform residents of the natural hazard risk in their vicinity and assist individuals and communities with measures that can be taken to reduce long-term risk. Examples include: Outreach programs to educate property owners and the public about risk and available mitigation measures to protect homes and structures Websites or pages dedicated to engaging residents to understand their role and take action GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

66 Preserving and/or restoring natural system functions supports hazard mitigation and resource protection. Examples include: Sediment and erosion control Stream corridor restoration Forest management Conservation easements Wetland restoration and preservation Community strategies and tactics are a critical component of mitigation action and require the skills of community planners, floodplain administrators, and emergency managers, along with information provided by a Risk MAP project or best available flood hazard data, to determine a mitigation plan to implement actions. Local Mitigation Plans Most communities within the river basin are included in local hazard mitigation plans. However, the majority of these plans are about to, or recently have, expired. The data and resources made available by this study may be used to refine and update the current hazard mitigation plans. Communities may wish to review and revise their plans when new data is made available. The availability of updated flood risk information gives the community a chance to review a range of possible actions such as the ones identified below: Local Hazard Mitigation Plan (Hazard Profile): The updated flood risk information provides an opportunity to review local hazard mitigation plans. The flood risk profile, hazard extent, and vulnerability assessment may be refined based on the Changes Since Last FIRM, water surface elevation grids, flood depth grids, and percent annual chance grids. Communities may reconvene their Mitigation Plan Steering Committee to identify how these narrative sections could be refined with the additional information. Regular updates and revisions to local hazard mitigation plans allow communities to inform future development and to prioritize and implement mitigation projects. Benefits accrue over the life of the project as losses are avoided from each subsequent hazard event. FEMA resources for hazard mitigation planning are available at: Local hazard mitigation plans help to: Protect public safety Prevent damage to community assets Reduce costs of disaster response and recovery Improve community capabilities Create safer, more sustainable development Local Hazard Mitigation Plan (Mitigation Strategies): Communities may review community assets, critical facilities and other vulnerable areas within a community to identify or refine the mitigation strategies and locate future mitigation projects to reduce long-term natural hazard risk throughout the community. FEMA s publication Mitigation Ideas: A Resource for Reducing Risk to Natural Hazards ( may provide some strategies and projects for the local Mitigation Plan Steering Committee to review. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

67 Mitigation Project Scope Preparation: Each year, communities may apply for the various FEMA Hazard Mitigation Assistance (HMA) grants available to assist in implementing mitigation actions. Communities may review their critical mitigation needs and choose to prepare project submittals for one of the grant opportunities FEMA offers. These HMA Grant Programs are managed by the State of Texas (grantee), which has the primary responsibility for selecting and administering the mitigation activities throughout the State. Individuals are not eligible to apply directly for HMA funds; however, communities may act as an eligible applicant or a sub-applicant may apply for funding on behalf of individuals For specific information on available HMA grant funding and current project priorities in Texas, please contact the appropriate State agency. FMA Grant Program Texas Water Development Board (TWDB) Kathy Hopkins Kathy.Hopkins@twdb.texas.gov (512) HMGP or PDM Grant Programs Texas Division of Emergency Management (TDEM) Paula Logan paula.logan@dps.texas.gov (512) Community Rating System (CRS): The NFIP s CRS is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Communities interested in the CRS program may contact Mark Lujan, FEMA Region 6 CRS Coordinator, by phone at (940) or via at mark.lujan@fema.dhs.gov. Adoption of Higher Standards: Community participation in the NFIP is voluntary. When a community joins the NFIP, a community must ensure that their adopted floodplain management ordinance and enforcement procedures meet NFIP requirements. NFIP minimum requirements include requiring permits for all development in the SFHA and ensuring that the GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

68 construction materials and methods used will minimize future flood damage. Higher standards such as freeboard, land use and zoning practices, and other approaches, allow communities to minimize future damages within the community by using more restrictive building codes and requirements. Risk Reduction Activities: The NFIP s Community Rating System Coordinator's Manual ( identifies a number of activities that communities can undertake to reduce their long-term risk. Higher standards, land use planning, future conditions modeling, and other approaches are available for consideration. Communities are not required to join the CRS program to benefit from the risk reduction provided by these activities. Severe Repetitive Loss Strategy: The primary objective of the SRL properties strategy is to eliminate or reduce the damage to residential property and the disruption to life caused by repeated flooding. The SRL Grant Program makes funding available for a variety of flood mitigation activities. Under this program, FEMA provides funds to State and local governments to make offers of assistance to NFIP-insured SRL residential property owners with mitigation projects that reduce future flood losses. Projects could include acquisition or relocation of at-risk structures and conversion of the property to open space, elevation of existing structures; or dry floodproofing for historic properties. Public Risk Awareness and Outreach Campaigns: Communities may use the new and existing flood hazard information to develop a public information and outreach campaign for their community. Since 2010, FEMA has conducted an annual nationwide study of flood risk awareness among U.S. households. Participants overwhelmingly responded that they expect and trust flood risk information when it comes from local community officials and staff. FEMA Region 6 has also developed the Risk Communication Guidebook for Local Officials ( which identifies a number of local communication activities. The Guidebook provides tools, templates, and resources for communities interested in developing a local outreach campaign; it is presented by Risk MAP project phases, similar to this report. FEMA support is available for local community Open House meetings. The CRS Coordinators Manual and the CRS Resources website (for Activity 300, available at can provide additional information for communities interested in local flood hazard and risk awareness outreach campaigns. Best Practices in Your Area A Mitigation Measure Designed to Save Lives. Hays County, Texas, uses a flood warning system to prevent motorists from being washed away or trapped in their vehicles. Warning System Alerts Residents in San Marcos. The city of San Marcos, Texas, wanted a way to communicate impending dangers if a tornado was spotted. The result was an early warning siren system installed to alert the public so they can move indoors quickly. Elevation Near Blanco River Survives Historic Flood. One man s decision to elevate his home saved it from floodwaters. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

69 Emergency Manager s Efforts in Hard-Hit Texas Area Ensure Community Readiness. The Emergency Management Coordinator and Floodplain Administrator took a proactive approach to engaging the communities he serves in preparing for disaster. Texas Water Development Board Helps Guadalupe County Safeguard Severe Repetitive Loss Properties. The Flood Mitigation Assistance (FMA) grant program assists States and communities. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

70 Appendix II: Resources State Partners Organization/Title Name Partner Location Contact Information Texas Water Development Board (TWDB) State NFIP Coordinator Michael Segner, CFM P.O. Box Austin, TX Phone: Web Page: Texas Division of Emergency Management (TDEM) State Hazard Mitigation Officer Paula K. Logan P.O. Box 4087 Austin, TX Phone: (512) Web Page: TXDPS.state.tx.us TWDB Texas Natural Resource Information Service (TNRIS) State Cooperating Technical Partner Coordinator Manuel J. Razo, GISP, CFM 1700 N. Congress Ave. Austin, Texas Phone: (512) Web Page: Watershed Follow Up Points of Contact Subject/Topic of Interest Name Contact Information Guadalupe-Blanco River FEMA Project Manager Project Outreach Diane Howe Risk Analysis Branch Phone: State of Texas Project Prioritization (FEMA work) Floodplain Management Floodplain Ordinance Community Assistance Visits Higher Standards Community Rating System Flood Insurance How to find and read FIRMs Letters of Map Change and Elevation Certificates Flood zone disputes Mandatory insurance purchase guidelines Map Service Center (MSC) & National Food Hazard Layer Larry Voice Risk Analysis Branch Myra Diaz Floodplain Management & Insurance Branch Mark Lujan FEMA Map Information exchange Phone: Phone: Phone: Phone: 877.FEMA.MAP ( ) Live Chat: GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

71 Texas Water Development Board The Texas Water Development Board s (TWDB) mission is to provide leadership, planning, financial assistance, information, and education for the conservation and responsible development of water for Texas. The TWDB has been designated by state law as the State NFIP Coordinating Agency for Texas. Within TWDB - Water Resources Planning & Information, you will find Flood Mitigation Planning where most of the flood related information and flood planning and mitigation grant resources reside. HELPFUL LINKS: FLOOD MITIGATION PLANNING FLOOD MITIGATION PLANNING STAFF NATIONAL FLOOD INSURANCE PROGRAM RESOURCES HOW TO JOIN, SAMPLE ORDINANCES, ETC. FLOOD MITIGATION ASSISTANCE GRANT PROGRAM TWDB FLOOD PROTECTION PLANNING PROGRAM SEVERE REPETITIVE LOSS GRANT PROGRAM FLOOD MITIGATION PLANNING WORKSHOPS AND TRAINING SCHEDULE COMMUNITY RESOURCES Guadalupe-Blanco River Authority Established by the Texas Legislature, GBRA was first created in 1933 under Section 59, Article 16 of the Constitution of Texas as a water conservation and reclamation district and a public corporation called the Guadalupe River Authority. In 1935, it was reauthorized by an act of the Texas Legislature (VCS Art ) as the Guadalupe-Blanco River Authority. GBRA provides stewardship for the water resources in its ten-county statutory district, which begins near the headwaters of the Guadalupe and Blanco Rivers, ends at San Antonio Bay, and includes Kendall, Comal, Hays, Caldwell, Guadalupe, Gonzales, DeWitt, Victoria, Calhoun and Refugio counties. Planning and resource development efforts are carefully coordinated within the broader consideration of regional and statewide water needs in order to fulfill GBRA's primary responsibilities of developing, conserving and protecting the water resources of the Guadalupe River Basin. GBRA FLOOD INFORMATION & RESOURCES GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

72 GBRA "Staying Safe" Flood Guide - a comprehensive manual explaining historic flood events, floodplains, the GBRA Hydro Lakes and their operation, a planning checklist, flood forecast points, radio station access information for the Guadalupe basin, flood insurance, and additional resources. Follow GBRA on Twitter GBRA issues up-to-date information during flood events using this service. This service is used for emergency purposes only. FLOOD PREPAREDNESS FOR GBRA S 6 HYDROELECTRIC LAKES The Interim Flood Preparedness Plan explains what happens in the event of local flooding, and includes maps, definitions and rainfall patterns. The Plan can be downloaded using provided link, or is available by contacting GBRA at Lake residents and others who may be affected by local flooding should refer to the appropriate Flood Tracking Chart for their area. These charts, which can be downloaded above or obtained from GBRA, allow the user to graphically relate the current flood flows at Lakes Dunlap, McQueeney, Placid and Meadow to historic and comparable conditions, lake levels, track current events and plan for an evacuation, if necessary. Lake Dunlap Flood Tracking Chart Lake McQueeney Flood Tracking Chart Lake Placid Flood Tracking Chart Meadow Lake Flood Tracking Chart GBRA encourages communities and residents to listen to KWED 1580 AM at these times for the latest flood reports and evacuation plans. In cooperation with local authorities, media and lake management groups, GBRA has developed materials to provide local residents, including those along Lakes Dunlap, McQueeney, Placid and Meadow, with valuable information during a flood event. If you have specific questions or need additional information about how to use these charts, please contact David Welsch or Tommy Hill at GBRA at POINTS OF CONTACT: Thomas Hill, PE Charles Hickman, PE Chief Engineer Manager of Project Engineering Phone: , xtn 245 Phone: , xtn 240 Fax: Fax: Thill@gbra.org chickman@gbra.org GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

73 Texas Floodplain Management Association (TFMA) TFMA is an organization of professionals involved in floodplain management, flood hazard mitigation, the NFIP, flood preparedness, warning and disaster recovery. The Association includes flood hazard specialists from local, state and federal governments, the mortgage, insurance and research communities, and the associated fields of flood zone determination, engineering, hydraulic forecasting, emergency response, water resources, geographic information systems, and others. Organization Contact Information Website Texas Floodplain Management Association (TFMA) Phone: Certified Floodplain Manager (CFM) Certification The Association of State Floodplain Managers (ASFPM) established a national program for certifying floodplain managers. This program recognizes continuing education and professional development that enhances the knowledge and performance of local, state, federal, and private-sector floodplain management professionals. The role of the nation's floodplain managers is expanding due to increases in disaster losses, the emphasis on mitigation to alleviate the cycle of damage-rebuild-damage, and a recognized need for professionals to adequately address these issues. This certification program will lay the foundation for ensuring that highly qualified individuals are available to meet the challenge of breaking the damage cycle and stopping its negative drain on the nation's human, financial, and natural resources. CFM is a registered trademark and available only to individuals certified and in good standing under the ASFPM Certified Floodplain Manager Program. For more information, you may want to review these available CFM Awareness Videos: What is the CFM Program? Who can be a CFM? What are the Benefits of a CFM? Study Materials for those interested in applying for the CFM certification can be found on the ASFPM Website at: Check the calendar on TFMA s website for in-person training sessions near you. For information on becoming a member and the exam application process in the State of Texas: Texas Quick Guide The Texas Quick Guide assists readers to understand more about why and how communities in the State of Texas manage floodplains to protect people and property. Flood-prone communities adopt ordinances and court orders that detail the rules and requirements for floodplain development. In case of conflict, that ordinance or court order and not this publication, must be followed. If you have questions, be sure to talk with your local planning, permit, engineering or floodplain management office. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

74 Interactive Preliminary Data Viewer (maps.riskmap6.com) To support community review of the study information and promote risk communication efforts, FEMA launched an interactive web tool accessible on-line at for the project areas. The project is broken up into counties based on the FIRM inventory, and the study data may be viewed here. For more information on the Interactive Preliminary Data Viewer, refer to a Region 6 Factsheet: What s your Flood Risk? Map Service Center Preliminary Map Data The FEMA Flood Map Service Center (MSC) is the official public source for flood hazard information produced in support of the NFIP. Use the MSC to find your official effective flood map, preliminary flood maps and access a range of other flood hazard products. FEMA flood maps are continually updated through a variety of processes. Effective information that you download or print from this site may change or become superseded by new maps over time. For additional information, please see the Flood Hazard Mapping Updates Overview Fact Sheet. At the Map Service Center, there are a two ways to locate flood maps in your vicinity. 1. Enter an address, place name or latitude/longitude coordinates, and click search. This will provide the current effective FIRM panel that the location exists on. 2. Or Search All Products, which will provide access to the full range of flood risk information available. GUADALUPE-BLANCO RIVER BASIN RISK REPORT October

75 Visiting the more advanced search option, Search All Products, users may access current, preliminary, pending and historic flood maps. Additionally, GIS data and flood risk products may be accessed through the site with these few steps Using the pull down menus, select, your state, county and community of interest. For this example, we selected Hays County - All Jurisdictions. After the search button is selected, the Map Service Center will return all items in the area. There are five types of data available. Effective Products. The current effective FIS, FIRM and DFIRM database (if available) is available through the MSC. If users click on the available effective products they are presented a breakdown of the available products. FIRM panels, FIS reports, Letters of Map Revision, Statewide NFHL and Countywide NFHL data may be available, as indicated in the breakdown on the right of the page Preliminary Products. Once a project area has been issued preliminary, the FIRM panels, FIS reports and preliminary DFIRM database are available for download. Once FEMA has a chance to share the draft study results and incorporate community comments, the Guadalupe-Blanco River Basin project areas will begin moving towards preliminary issuance. Pending Products. After the appeal and comment period is held and the received appeals and comments are incorporated, the Letter of Final Determination (LFD) is issued, establishing an effective issuance date for the study. Panels are available here once an LFD is issued. Historic Products. A range of historic flood hazard maps, FIS texts and LOMCs are available through the MSC. Flood Risk Products. The Flood Risk Report, Flood Risk Map and Flood Risk Database will be made available through the MSC once it has been compiled and completed. These products are made GUADALUPE-BLANCO RIVER BASIN RISK REPORT October