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OR 93-634 Trinity River Corridor Development ORDINANCE OF THE CITY OF COPPELL, TEXAS ORDINANCE NO. 93634 AN ORDINANCE OF THE CITY OF COPPELL, TEXAS, AMENDING CHAPTER 16 OF THE CODE OF ORDINANCES OF THE CITY OF COPPELL BY ADDING ARTICLE 16-5, CERTIFICATION OF TRINITY RIVER CORRIDOR DEVELOPMENT; PROVIDING DEFINITIONS; PROVIDING FOR CORRIDOR DEVELOPMENT CERTIFICATION PRIOR TO FLOODPIAIN ALTERATIONS; PROVIDING A SEVERABILITY CLAUSE; PROVIDING A REPEALING CLAUSE; PROVIDING FOR A PENALTY OF FINE NOT TO EXCEED TWO THOUSAND DOLLARS ($2,000.00); AND PROVIDING AN EFFECTIVE DATE. WHEREAS, the City Council of the City of Coppell, after full consideration, finds it necessary and-appropriate to require certification by the City Engineer of floodplain alteration or development in the Trinity River Corridor within the city limits of the City of Coppell, and WHEREAS, the present ordinances and regulations of the City of Coppell are inadequate to control the height of flood waters within the Trinity River within and adjacent to the corporate limits of the City of Coppell; and WHEREAS, an emergency exists for the immediate preservation of the public business, property, health, safety and general welfare of the public; NOW THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF COPPELL, TEXAS: SECTION 1. That Chapter 16 of the Code of Ordinances of the City of Coppell be, and is hereby, amended, in part, by adding Article 16-5, Certification of Trinity River Corridor Development, to read as follows, to-wit: -1- "ARTICLE 16-5 CERTIFICATION OF TRINITY RIVER CORRIDOR DEVELOPMENT Sec. 16-5-1 DEFINITIONS Corridor Development Certificate Manual means the manual by that title dated January 31, 1992, which is attached to this ordinance and kept on file in the office of the city secretary. Floodplain alteration means any construction of buildings or other structures, mining, dredging, filling, grading, or excavation in the floodplain. Trinity River Corridor means the portion of the bed and banks of the Elm Fork of the Trinity River and Demon Creek (east of MacArthur Blvd. to its confluence with the Elm Fork of the Trinity River) within the Coppell city limits. Sec. 16-5-2 CERTIFICATE REQUIRED A person commits an offense if he or she makes any floodplain alteration within the Trinity River Corridor without first obtaining a corridor development certificate from the City Engineer. It is a defense to prosecution that an exemption or waiver has been obtained in accordance with Sections 16-5-4 and 16-5-5 of this article. Sec. 16-5-3 APPLICATION FOR CORRIDOR DEVELOPMENT CERTIFICATE A. An application for a corridor development certificate must be filed with the City Engineer on a form furnished by the Engineering Department. B. The City Engineer shall deny an application for a certificate for floodplain alteration which does not comply with the standards contained in the Corridor Development Certificate Manual unless an exemption from or waiver of those standards is obtained in accordance with Sections 16-5-4 and 16-5-5 of this article. Sec. 16-5-4 EXEMPTIONS A. An exemption from the requirements of this article may be obtained if the floodplain alteration involves the following -2- activities: 1. ordinary maintenance of and repair to flood control structures; 2. the construction of outfall structures and associated intake structures ff the outfall has been permitted under state or federal law; 3. discharge of material for back/ill or bedding for utility lines, provided there is no significant change in pre- existing bottom contours and excess materials are removed to an upland disposal area; 4. bank stabilization; 5. any project listed in the U. S. Army Corps of Engineers March 1990 Recormalssance Report, which is attached as Appendix A to the Corridor Development Certificate Manual, provided the approval, permit or authorization has not expired and no significant changes have occurred since the approval, permit, or authorization was issued. B. If the City Engineer determines that an application for an exemption falls within one of the categories listed in paragraph (A), the City Engineer shall issue a written exemption from the requirements of this article. Sec. 16-5-5 Wb~WERS If the City Engineer determines that the application for a Corridor Development Certificate does not comply with all of the standards contained in the Corridor Development Certificate Manual, the applicant may apply for a waiver to any standards contained in the Corridor Development Certificate Manual. B. An application for a waiver must be made to the City Engineer who shall schedule the application for consideration by the City Council. C. The City Council may grant a waiver provided the waiver will not violate any provision of F~deral, State law, or City -3- ordinance, result in increased flood levels, or endanger life or property." SECHON 2. If any article, paragraph or subdivision, clause or provision of this ordinance shall be adjudged invalid or held unconstitutional, the same shall not affect the validity of this ordinance as a whole or any part or provision thereof, other than the part so decided to be invalid or unconstitutional. SECTION 3. That all provisions of ordinances of the City of Coppell, Texas, in conflict with the provisions of this ordinance be, and the same are hereby, repealed, and all other provisions not in conflict with the provisions of this ordinance shall remain in full force and effect. SECTION 4. Any person, firm, or corporation violating any of the provisions of this ordinance or of the Code of Ordinances, as amended herein, shall be deemed guilty of a misdemeanor and, upon conviction, shall be punished by a penalty of fine not to exceed the sum of Two Thousand Dollars ($2,000.00) for each offense, and each and every day such offense is continued shall constitute a new and separate offense. SECTION 5. This ordinance shall take effect immediately from and after its passage and the publication of the caption as the law and charter in such cases provide. DULY PASSED by the City Council of the City of Coppell, Texas on the / ~/L~'~; day of d~'~' e ': JL t( L L, , 1993. APPROVED: -4- ATFEST: APPROVED AS TO FORM: 'CITY ATI'~EY / rGS/jd (12/3/93) Flood Facts Coppell NCTCOG September 22, 1993 Recent Flood Damages o The U.S. Army Corps of Engineers (COE)'s Report on Flooding: April -May 1990 reported, "VVellington Place Apartments at 230 South MacArthur had water in cars and apartments...The Long Branch Saloon was surrounded by water on three sides as land reclaimed from the floodway gave way to erosion from the rapid flow of the Elm Fork." o The COE's Report on Flooding: April -May 1990 also reported damage as "Sandy Lake Road was closed as Denton Creek overflowed its banks to flood area homes and business" and "The combined flooding from Sandy Lake Road and Beltline Road backed up into Riverchase Golf Course making the clubhouse an island." o The 1990 COE Reconnaissance Report found a Standard Project Flood would cause a potential $359,000,000 of damage in Coppell; with CDC in place, the COE estimated that only $215,000,000 in damage would occur during such a flood. Flood Plain Manaqement o The History of flood plain management only dates back to 1969, when FEMA's National Flood Insurance Program began. However, there have always been inadequacies in the Federal approach, including: -Reactire planning, -An inflexible approach to diverse flood situations and -Static modeling based on out of date assumptions o A New Direction began in 1985, when the COE, concerned with the rapid development of the Trinity River floodplain, conducted a Regional Environmental Impact Statement to investigate flood risks. The dramatic findings prompted local governments to take action; becoming parties to a Record of Decision and passing resolutions in support of continued study and a common permit process. CITY OF DALLAS STEVE BARTLETT Mayor November 8, 1993 Honorable Mayor Tom Morton City of Coppell P.O. Box 478 Coppell, Texas 75019 Re: Coordinator Development Certificate (CDC) Process Implementation Dear Honorable Mayor Tom Morton The City of Dallas has participated along with your City and ten other ~urisdictions in a cooperative management program in pursuit of a COMMON VISION for the Trinity River Corridor since 1986. We have now reached the point where it is time to begin putting the means to accomplish our COMMON VISION in place. The first and most important step in doing this is adoption of the Corridor Development Certificate (CDC) process. This process which was adopted by the Upper Trinity River Feasibility Study Steering Committee will provide for a common development permitting strategy throughout the Trinity River Corridor. It will address the potentially serious concerns identified in the Regional Environmental Impact Statement on the Upper Trinity River issued by the U.S. Army Corps of Engineers and help to insure that development within the Corridor can proceed in a responsible manner. To date, however, only three participating communities have taken action to fully implement the CDC process. The City of Dallas formally adopted the CDC process in May of this year. The CDC process is crucial in the region's attempt to stabilize the level of flooding risk in the Corridor. As always, the City of Dallas remains OFFICE OF THE MAYOR CITY HALL DALLAS TEXAS 75201 TELEPHONE 214 670-4054 Honorable Mayor Tom Morton Page 2 November 8, 1993 committed to responsible floodplain management of the Trinity River as this will serve to benefit the entire region. I urge you to support implementation of the CDC process as soon as possible so that together we may continue to fulfill the COMMON VISION that we began those Steve Bartlett cc: Clifford V. Keheley, First Assistant City Manager Ted Benavides, Assistant City Manager Ram6n F. Miguez, Director of Public Works CORRIDOR DEVELOPMENT CERTIFICATE MANUAL for the TRINITY RIVER CORRIDOR North Central Texas JOINTLY PREPARED BY: The Cities of Arlington Dallas Grand Prairie Carrollton Farmers Branch Infing Coppail Fort Worth Lewisville The Counties of Dallas Denton Tarrant Special Districts Tarrant County Water Control and Improvement District Number One Trinity River Authority of Texas United States Army Corps of Engineers, Fort Worth District Federal Emergency Management Agency North Central Texas Council of Governments AS APPROVED BY THE TRINITY RIVER STEERING COMII~ ~ ~ t:E ON: MAY 23, 1991 FIRST EDITION, JANUARY 1992 [01-31-92] CORRIDOR DEVELOPMENT CERTIFICATE MANUAL for the TRINITY RIVER CORRIDOR North Central Texas JOINTLY PREPARED BY: The Cities of Arlington Dallas Grand Prairie Carrollton Farmers Branch Irving Coppell Fort Worth Lewisville The Counties of Dallas Denton Tarrant Special Districts Tarrant County Water Control and Improvement District Number One Trinity River Authority of Texas United States Army Corps of Engineers, Fort Worth Disb'ict Federal Emergency Management Agency North Central Texas Council of Governments AS APPROVED BY THE TRINrrY RIVER STEERING COMMi i ~ e-E ON: MAY 23, 1991 FIRST EDITION, JANUARY 1992 [01-31-92] FOREWORD A Steering Committee of elected officials has been guiding the interjurisdictional program and has adopted a Regional Policy Position for the Trinity River Corridor. This Policy Position states that, "Until a major flood control program can be completed to reduce or eliminate existing flood threats, the continuing pressure for development of the floodplain must be managed in the most practical and equitable manner possible to at least stabilize current levels of flooding risk. Attention must also be placed on meeting water and other environmental quality goals and implementing desired regional public facilities.' The Corridor Development Certificate (CDC) Team of the Trinity Corridor Flood Management Task Force has drafted this Manual over a two and one-half year period. The goal of the CDC process is to avoid any adverse cumulative impacts from development in the corridor. The CDC Team has strived to address many of the complex issues involved in the development of this Manual in order to create a sound and equitable process for the development of the Trinity River Corridor. The Flood Management Task Force completed its review of this Manual on May 1, 1991. It was approved by the Trinity Corridor Steering Committee of elected officials on May 2'3, 1991. However, there are significant topics that still require discussion. It is important to realize that this Manual represents a dynamic process that will continue to develop and change over time. As more detailed information develops, the requirements of this process will change. The CDC Team has crafted this Manual using the following three primary sources of material: U.S. Army Corps of Engineers Record of Decision; April, 1988 Fort Worth Development Policy; North Central Texas Council of Governments Trinity River Steering Committee Statement of Principles; January, 1988 THIS MANUAL REFLECTS POLICY ENDORSED BY THE TRINITY RIVER STEERING COMMFFFEE. EACH PARTICIPATING JURISDICTION RETAINS PERMITTING AUTHORITY BUT BASES ITS PERMIT DECISION ON THE SET OF COMMON PERMIT CRITERIA DESCRIBED HEREIN. CDC MANUAL TABLE OF CONTENTS SECTION ITEM DESCRIPTION PAGE FOREWORD 1,0 DESCRIPTION OF CORRIDOR DEVELOPMENT CERTIFICATE (CDC) 1.1 Purpose of the CDC Process 1 1 ~2 Geographic Area of Regulation 2 1.3 Development Activities Affected 3 1.4 Exemptions and Variances 4 1.5 Definitions 5 1.6 Penalties for Unauthorized Construction 7 2.0 CDC - COMMON PERMIT CRITERIA 8 3.0 CDC APPLICATION REQUIREMENTS 10 4.0 THE CDC PROCESS 12 5.0 THE RELATED STATE/FEDERAL REGULATORY PROGRAMS 14 CDC MANUAL TABLE OF CONTENTS (continued) APPENDICES APPENDIX A Hydrologic and Hydraulic Baseline Information Excerpt of March 1990 Upper Trinity River Reconnaissance Report - - List of "Grandfathered" Developments APPENDIX B Regional Policy Position on Trinity River Corridor - 1989 Resolution for a Joint Corridor Development Certificate Process U.S. Army Corps of Engineers Record of Decision - Regional Environmental Impact Statement: Trinity River and Tributaries Draft Statement of Principles For Common Permit Criteda - Trinity River Corridor (January 28, 1988) APPENDIX C Mailing Addresses and Points of Contact List of Acronyms Section 1.0 DESCRIPTION OF A CORRIDOR DEVELOPMENT CERTIFICATE (CDC) 1.1 PURPOSE OF CDC PROCESS The Trinity River Steering Committee, herein called the Steering Committee, composed of elected officials of participating agencies and the North Central Texas Council of Governments Executive Board have adopted a Regional Policy Position on Trinity River Corridor. It calls for a cooperative management program using common permit criteria which are derived from criteria now being applied by the U.S. Army Corps of Engineers (COE) in their permitting process. It also calls for expanded technical assistance by the COE and a regional review and comment process by other local governments for major actions within the Corridor. In 1988, the Statement of Principles For Common Permit Criteria was drafted in order to address common problems and opportunities faced by cities along the Corridor. (See Appendix B) This Statement represented the best attempt at a regional consensus on permit crIteria within the 90 days available for response to the COE Final Regional Environmental Impact Statement (REIS) for the Trinity River. it was developed by the Flood Management Task Force through several drafts, with input from the NCTCOG staff, COE, and other governmental agencies and private sector representatives. A signfficant finding of the Final REIS indicated that different local policies for floodplain reclamation had the potential of increasing the risk of flooding and the potential for water quality and environmental degradation. The participating nine cities and three counties have expressed their support for a cooperative management program whereby each city retains development permit authority within its jurisdiction but bases its permit decision on a set of common permit criteria. It is the express purpose of this cooperative process to satisfy the requirements of the Federal Emergency Management Agency (FEMA) and the Texas Water Commission (I'WC) regarding city floodplain permIt actions within the Trinity River Corridor and to effect close coordination with the U.S. Army Corps of Engineers and other State or Federal agencies that have their own permit processes. The Corridor Development Certificate (CDC) Process does not supersede other State and Federal programs. The CDC Process represents the high level of commitment exhibited by the FEMA, the 'TtVC and the COE. it has been understood by these agencies that the implementation of the CDC Process will necessitate some procedural changes in each of these organizations. The long-term commitment and cooperation is evident and as the CDC Process evolves, appropriate actions will be taken to improve the CDC Process. Please recognize that the major objective of the CDC Process is to uniformly evaluate development in the Trinity River Corridor based on common crIteria by an equitable process. Logically, this will affect some existing design criteria and procedures used by all parties involved. It is important to remember that all permIt decisions will be made by the participating local governments based on the common permIt crIteria contained in this manual. 1.2 GEOGRAPHIC ARE. ~F REGULATION The Trinity River Corridor is defined in the Interlocal Agreement as the bed and banks of the river segments from the dams of Lewisville Lake, Grapevine Lake, Lake Worth, Benbrook Lake, Lake Arlington, and Mountain Creek Lake, downstream to the area near Post Oak Road and the Trinity River in southeast Dallas County, and all of the adjacent land area and all watercourses contained within the boundaries of the river floodplain as designated by the Steering Committee which is composed of elected officials for the Trinity River Corridor Program through NCTCOG. The Trinity River Corridor will be delineated into two zones - the Regulatory and Review Zones. These zones are incorporated into the Trintty River Corridor Map - CDC Regulatory and Review Zones which are available for inspection at the local permitting authority and at NCTCOG. These zones are defined in Section 1.5 DEFINITIONS ofthis Manual. The Regulatory Zone includes all of the area within the 100-year floodplain as defined and the Review Zone includes the remaining area between the Regulatory Zone and the designated Standard Project Flood (SPF) boundaries of the Trinity River Corridor. The digital map has been approved by the Steering Committee. This digital map is maintained by NCTCOG and is available at a 1"= 1,000' scale or larger, from NCTCOG, the COE - Fort Worth District, or the participating local government. The Regulatory Zone is the area in which any and all development activities will require a CDC permit to occur. The Review Zone is the area in which development activities will require review of Pad 1 of the CDC application by the appropriate CDC/Floodplain Administrator(s). Although no permit is automatically required, the purpose of this zone will be to maintain data on activities occurring in important areas of the watershed. In addition, the cities participating in this program may require Regulatory Zone requirements for areas in the Review Zone within the municipality's jurisdiction. The Trinity River Corridor Map and the CDC Regulatory and Review Zones Map were endorsed on July 25, 1991 and were officially approved by the Trinity River Corddor Steering Committee on December 19, 1991. 2 1.3 DEVELOPMENT AC. IES AFFECTED Any public or private development within the Regulatory Zone of the Trinity River Corridor must obtain a CDC prior to start of any development activity, unless specifically exempted as discussed in Section 1.4 EXEMPTIONS AND VARIANCES. A development activity means "any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operations." To assure consistency with TVVC requirements, development activity also includes "any levee or other improvement". A development activity by a city within the Trinity River Corridor will be treated like any other application for a CDC and will undergo the COE permit process, and if applicable, the regional review and comment process discussed later. To avoid conflicts between adopted policy and city ordinances, the municipal application will then be considered and acted upon by that jurisdiction's policy-making body, e.g., City Council. NOTE: Throughout this CDC Manual the term 'City' is used. However, in unincorporated areas, the respective county or special district would be applicable. 3 1.4 EXEMPTIONS AND dANCES if a development that is partly or totally within the Trinity River Corridor can show in writing that it meets any of the conditions below, it may be exempted by the city from the CDC permit process. A development is required to request an exemption in writing, using the CDC form, and the city is required to consider such a request. [NOTE: the Applicant should still contact the COE, FEMA, and the TVVC to determine if the development is subject to specific permit requirements by those agencies.] ff granted, this written exemption and other pertinent information will be maintained on file by the city and will be provided to NCTCOG for the permanent records. EXEMPTIONS TO THE CDC PERMIT PROCESS: A. Ordinary maintenance and repairs of any operational flood control structures. B. Outfall structures and associated intake structures where the ouffall has been permitted under the Federal NPDES or State TPDES program. C. Discharge of material for backfill or bedding for utility lines, provided there is no significant change in pre-existing bottom contours and excess material is removed to an upland disposal area. Do Bank stabilization activities. E. Property that is (1) completely outside the Regulatory Zone but within the Review Zone; (2) determined by the COE that no permits are required; and (3) defined or identffied by city ordinance such that the property does not require the Applicant to undergo the CDC process in the Review Zone. F. Specffic Prior Developments - The existing development projects in Section 1.5 DEFINITIONS of this Manual. VARIANCES TO COMMON PERMIT CRITERIA: Under certain circumstances a variance from these common permit criteria may be issued by the city. A variance may be sought by any public or private development that cannot meet the established common criteria as detailed in Section 2.0 CDC - COMMON PERMIT CRITERIA of this Manual. A variance shall be any modification of the literal provisions of the CDC Manual when strict enforcement of the CDC process would cause undue hardship, owing to circumstances unique to the individual property on which variance from the process is requested. Variances may also be issued for public projects deemed to be in the overall regional public interest, as determined by the jurisdiction's policy-making body, e.g., City Council. The petition seeking a variance must include a completed Part I - Section A of the CDC Application. The application will then undergo COE technical review and regional review and comment by signatories to the Interlocal Agreement. The proposed variance must be discussed and supported by the Applicant and the local permitting signatory in this Manual. Any variance granted to a property within the Regulatory Zone must be reviewed and approved by the city council or jurisdiction(s) in which the property is located. The final decision of the City will be provided to the Applicant and copies will be placed in record at NCTCOG. 4 1.5 DEFINITIONS Trinity River Corridor - For the purpose of the CDC Process, the Trinity River Corridor is defined as the bed and banks of the river segments from the dams of Lewisville Lake, Grapevine Lake, Lake Worth, Benbrook Lake, Lake Arlington, and Mountain Creek Lake downstream to the point on the mainstem of the Trinity River near Post Oak Road in southeast Dallas County, and all of the adjacent land area and all watercourses contained within the boundaries of the river floodplain as designated by the approved Trinity River Corridor digital map maintained on computer by NCTCOG. Upper Trinity River Basin - the Trinity River watershed upstream of the vicinity of Post Oak Road and the mainstem of the Trinity River in southeast Dallas County. 100-Year Flood - Also known as the base flood. It is the flood having a one percent (1%) probability of being equalled or exceeded in any given year. Conveyance - A measure of the stream carrying capacity of a channel section. It is dependent on the cross-section geometry and friction or roughness characteristics of the channel. Design Flood - A particular predicted flood condition that is used as a basis for design of flood protection facilities such as channels or levees. Those facilities are generally sized to provide protection against the design flood wIth some freeboard provided as an additional factor of safety. Development Activity - Any manmade change to improved or unimproved real estate, including but not limIted to, buildings or other structures, the construction of levees, mining, dredging, filling, grading, paving, excavation, or drilling operations. Exemptions - Developments that fall outside the scope and intent of the CDC process as described in Section 1.4 EXEMPTIONS AND VARIANCES. Freeboard - The vertical distance from the predicted water surface of a particular flood event to the lowest adjacent top of bank of a flood protection facility, e.g., a channel or levee. Regulatory Zone - The area within the 100-year floodplain of the specified reach of the Trinity River as defined by the latest approved version of the digital Trinity River Corridor Map - CDC Regulatory and Review Zones maintained by NCTCOG. (See Appendix A) Review Zone - The area between fie Regulatory Zone and the designated boundaries of fie Trinity River Corridor as defined by the latest approved version of the digital Trinity River Corridor Map -CDC Regulatory and Review Zones. The Steering Committee has designated these boundaries as the SPF 1995 Baseline boundaries as defined in the COE March 1990 Upper Trinity River Reconnaissance Report, herein referred to as the March 1990 Reconnaissance Report, and as modffied by the Trinity River Flood Management Task Force and delineated by the NCTCOG Regional Geographic Information System (GIS). (See Appendix A) $pecffic Prior Development ("Grandfathered Projects") - Under the CDC process, existing projects that are included in the COE baseline modeling are identified as Specific Prior Development and may not require a certificate. These projects include those fiat; 1) are listed in the March 1990 Reconnaissance Report (See excerpt in Appendix A), and/or 2) have been approved by the appropriate participating jurisdiction as of the date of the 5 adoption of this m, ,. If any significant changes in the, ,ct occur or if the term of Permit Validity expires, the project may lose its specific prior development status and be subject to the CDC process. This provision of the process only applies to the CDC requirement; it does apply to any other State or Federal regulatory program. Projects not specifically addressed by the above conditions may be exempted by the appropriate participating jurisdiction and agencies. Standard Project Flood (SPF) - The Standard Project Flood is the flood that may be expected from the most severe combination of meteorologic and hydrologic conditions that are considered to be reasonably characteristic of the geographical region involved, excluding extremely rare combinations. In practical terms, a SPF usually has a 0.3 to 0.08 percent probability of being equalled or exceeded in any given year, and is usually between 40 and 60 percent of a Probable Maximum Flood (PMF). The SPF represents a "standard" against which the degree of protection selected for a project may be judged and compared with protection provided at similar projects in other localities. Term of Permit Validity ("Sunsetting of Permit") - if no development activities occur by the end of five years from the date of issuance, the applicant may submit a written request within thirty days for up to a three-year extension or the CDC permit shall cease to be valid. The City may grant up to a three-year extension. If no request for an extension is made at the end of the thirty day period, the Applicant must reapply for a CDC permit. Summary project status reports are required to be submitted to the CDC/Floodplain Administrator annually. Any signfficant changes to the project by the Applicant or the City requires the re-evaluation of the permit and may result in a reapplication. Valley Storage - The temporary storage of floodwater provided by the channel and overbank areas of the floodplain. Variance - A variance is any modification of the common permit criteria of the CDC Manual when strict enforcement of the CDC process would cause undue hardship owing to circumstances unique to the individual property on which the variance is granted, or when the project would be in the overall regional public interest, as determined by the jurisdiction's policy-making body, i.e., City Council. ADDITIONAL CLARIFICATIONS: Significant changes to project by the Applicant or the City can be quantified by the expression: Those changes that materially affect permitted valley storage, conveyance, and environmental impacts. The CDC permit will be considered as a portion of the property. The Applicant shall be required to officially file the CDC permit in the county records. Project plans are intended to provide the necessary level of detail in order to properly evaluate the development request. As a practical matter, conceptual plans will probably suffice to initiate the permitting process; however. plans of sufficient detail to adequately analyze the project's impact using the CDC criteria as outlined in this manual are necessary prior to the CDC permit being issued. 1.6 PENALTIES FOR I~ ,THORIZE';::) CONSTRUCTION Failure to comply with the provisions of the policies and regulations found within CDC Manual will be subject to the penalties provided for under the floodplain management ordinance or regulations of the jurisdiction. For further information, please consult the appropriate municipality for floodplain management ordinance requirements and the U.S. Army Corps of Engineers - Fort Worth District and the Texas Water Commission for applicable Federal and State requirements. 7 Section 2.0 CDC - COMMON PERMIT CRITERIA The following common permit criteria describe a consistent design level of protection which should be met for all CDC applications, unless granted a variance. This detailed Manual has been developed to assist Applicants. The Applicants for a CDC would be required to provide sufficient detailed information to document criteria compliance. The hydrologic baseline to be used in analyzing permit applications will be in accord with Table 1 in Appendix A. More detailed hydrologic studies may be performed provided the Applicant receives prior approval. Hydraulic models representing existing conditions should be based on the March 1990 Reconnaissance Report and its updates. Adjacent projects permitted but not reflected in the current hydraulic models should be included in the Applicant's hydraulic information. Hydrologic information from the 1990 Reconnaissance Report for the FUTURE CONDITIONS WITH CDC SCENARIO (See Table 1 in Appendix A) should be used for design and analysis. SPF Future Condition Discharges for the West Fork of the Trinity River in the Reconnaissance Report has been supplemented considering two additional storm centerings. For more detailed hydrology, the appropriate CDC/Floodplain Administrator may request additional information from the COE. The burden of proof of compliance with these criteria rests with the permit Applicant. A. Hydraulic Impacts - Projects within the Regulatory Zone. The following maximum allowable hydraulic impacts will be satisfied, using reasonable judgemerit based on the degree of accuracy of the evaluation, and using cross-sections and land elevations which are representative of the reaches under consideration: 1. Water Surface Elevations - No rise in the 100-year flood or signfficant rise in the SPF water surface elevations for the proposed condition will be allowed. 2. Storage Capacity - The maximum allowable loss in storage capacity for lO0-year flood and SPF discharges will be 0% and 5%, respectively. 3. Velocities - Alterations of the floodplain may not create or increase an erosive water velocity on-site or off-site. 4. Conveyance - The floodplain may be altered only to the extent permitted by equal conveyance reduction on both sides of the channel. B. Hydraulic Impacts - Tributary Projects. For portions of tributary projects that are within the Regulatory Zone of the Trinity River, the maximum hydraulic impacts are the same as those for mainstem Trinity River Regulatory Zone projects. C. Cumulative Impacts. The upstream, adjacent, and downstream effects of the Applicant's proposal will be considered. The proposal will be reviewed on the assumption that adjacent projects will be allowed to have an equitable chance to be built, such that the cumulative impacts of both will not exceed the common criteria. Hydraulic data should be supplied to show the impacts of adjacent developments,(e.g., HEC-2 modeling with blocked off conveyance). 8 D. Design Level of FI, Protection. The engineering anal~ dill include the effects of the Applicant's proposal on the 100-year flood and SPF and should demonstrate meeting COE, FEMA, Texas Water Commission, and local criteria for both flood events. 1. For levees protecting urban development, the minimum design criterion for the top of levee is the SPF plus four feet, unless a relief system can be designed that will prevent catastrophic failure of the levee system. 2. For fills, the minimum design criterion is the 100-year flood elevation plus one foot, unless a relief system can be designed that will prevent catastrophic failure. E. Borrow Areas. The excavation of borrow areas to elevations lower than the bottom elevation of the stream is generally hydrologically undesirable. The volume of such excavations. above the elevation to which the area can be kept drained, may be considered in hydrologic storage computations. F. Preservation of Adjacent Project Storage, The Applicant will be required to respect the valley storage provided by adjacent projects by ensuring that their hydraulic connection to the river is maintained. ff the project blocks the hydraulic connection of the adjacent project, then the Applicant will be required to provide additional valley storage to offset the loss caused by the blockage of the hydraulic connection. NOTE: The COE will examine other criteria for the purpose of evaluating new COE permit applications. The criteria include; A. Wetlands and Fit, it & Wildlife Resources Impacts B. Runoff C. Habitat Mitigation D. Other Regional Needs and Plane Jurisdictions may require that Regulatory Zone criteria be applied to projects occurring within the Review Zone. For further information on COE review, please contact the COE Fort Worth District Permit Section at (817) 3342681. 9 Section 3.0 CDC APPLICATION REQUIREMENTS An application for a CDC will be submitted on standard forms furnished by the City or facsimiles thereof, and be signed by the owner of the property or appropriate agent. To insure that all proposed developments are afforded a complete and consistent level of analysis, the application will include, but not be limited to: A. Project Plans B. Hydrologic Data C. Hydraulic Data D. Elevation - Storage - Discharge Data E. COE Jurisdictional Review F. Resource Data G. Maintenance and Operation Data H. Erosion Control More detailed descriptions of these requirements are presented below: A. Project Plans. Project plans would be submitted as part of the CDC application at a scale that provides adequate detail of the whole project as well as individual features of the project. The plan should show the location of the FEMA RegulatonJ Floodway and the layout of cross-sections used in the hydraulic model. Proposed changes to the Floodway should be clearly shown. !,See Section 1.5 DEFINITIONS for additional clarffication) B. Hydrologic Data. Design discharges for the 100-year and SPF storm events shall be based on urbanization consistent with the Future Conditions W~th CDC Scenario of the March 1990 Reconnaissance Report or supplemental data provided by the COE, whichever is larger. (See Table 1 in Appendix A). The Applicant should clearly identify these design discharges, including source and date. In conjunction with the common policies described herein, the Future Conditions W~th CDC Scenario (as supplemented by the COE with two additional storm cantarings on the West Fork of the Trinity River) are reflective of a watershed with modest stability in future discharges. However, future discharge corrections will undoubtedly be required. For consistency in permit review and evaluation of design requirements, revisions to the discharges contained in the March 1990 Reconnaissance Report should be scheduled and coordinated among the affected jurisdictions. C. Hydraulic Data. Water surface elevations at the upstream, middle, and downstream ends of the project (for pre-project and with-project conditions) for lO0-year flood and SPF discharges consistent with the Future Conditions With CDC Scenario should be provided with the CDC application. Hydraulic calculations should be continued for a distance great enough upstream and downstream of project to verify water surface elevations are not raised by the proposed hydraulic modifications. In all cases, the best available data on water surface elevations should be utilized. 10 Printouts and plots. .,i an approved hydraulic model (HEL , of cross-sections for pre- project and with-project conditions should be part of the CDC application. Water surface profiles for 100-year flood and SPF for pre-project and with-project conditions should also be included. The number and location of sections should be adequate to describe and support documented computations. D. Elevation, Storage, and Discharge Data. Elevation, storage, and discharge data (i.e., using the March 1990 Reconnaissance Report the Future Conditions With CDC Scenario discharges with supplements in combination with the most reliable elevation data available) for pre-project and with-project conditions should be developed: O within the project borders alone, 0 considering full cross-section widths across the river or creek, and 0 indicating percent of change in valley storage capacity. Storage change is to be considered "on-site" (i.e., within upstream and downstream limits and property limits of the project). In addition. if any valley storage is lost elsewhere due to the project, storage change is to be addressed on a full cross-section width basis. E. COE Jurisdictional Review. Applicants should provide written correspondence from the COE indicating whether the Corps jurisdiction applies to the project area. NOTE: a formal determination on the application itself occurs at a later step in the CDC process. F. Resource Data. Applications should include at least the following information on environmental/cultural resources: (1) engineering and environmental resource data which tabulates the impact on land cover types an~ habitat units, and (2) any plans for erosion control, general landscaping, or other practices to minimize potential water quality and other environmental impacts. Projects areas which are within COE jurisdiction will also need to provide identification of mitigation required for loss and/or alteration of high value habitats. Developments which propose to relocate or alter a natural channel should also submit more detailed environmental data and a stream rehabilitation program. G. Maintenance and Operation Data. An estimate of annual maintenance and operation costs for the hydrologic and hydraulic aspects of the project should be provided. Parties responsible for costs associated with maintenance and operation in perpetuity for the "as designed" condition should be clearly identffied. if maintenance is to be accomplished by an agent other than the community, a legal provision for community monitoring and backup maintenance is required. H. Erosion Control Plan. The regulating jurisdiction should be contacted to obtain specffic information regarding local erosion control requirements and plan submittals. 11 Section 4.0 THE CDC PROCESS There are five basic steps in the CDC application review process as depicted in the accompanying chart and summarized follows: NOTE: Throughout this CDC Manual the term 'City' is used, however, In unincorporated areas, the respective county would be applicable. Step 1. Determination of Applicability by City - Does the City have jurisdiction regarding this application? Is it within the Trinity River Corridor? Is it within the Regulatory or Review Zone? Is it exempted from the process? If the City has jurisdiction for the project, the review process proceeds. ff not, the City informs the Applicant in writing. Step 2. Jurisdictional Review bv COE - The Fort Worth District staff of the COE will perform the jurisdictional review and provide preliminary hydraulidhydrologic technical dat~ required by the common permit criteria in coordination with the City and the Applicant. This review will occur within thirty (30) days of submittal to COE, provided ALL required data has been received. Step 3. Notice of Intent to Process bv City - The City will review the application materials and COE findings within its own time frame. ff the City decides to deny the application at this point, the process ends. NCTCOG will be provided a copy of this action. ff the City decides to continue the process, then it will assure that the application is complete, assign a CDC identification number, and provide the lull application to the COE for a permit determination, to FEMA If a conditional map revision is required, to the Texas Water Commission If their jurisdiction applies, and to NCTCOG for incorporation into the Trinity River Information Network (TRIN) tracking system. Step 4. Parallel COE, FEMA, TVVC, and Reaional Review - ff the application is subject to a COE individual permit, then the public notice and review/comment process will be initiated by COE (including the other affected local governments). ff the application is not subject to a COE individual permit, then the City will distribute a notice and materials directly to the other signatories to the Intedocal Agreement. The FEMA and TVVC review processes will occur simultaneously. ff under COE jurisdiction, COE will decide whether to issue its permit and so notify the City and Applicant. Likewise, FEMA will notify the City regarding any requested conditional map revision and the TWC for any plan of reclamation. Signatories of the Inferlocal Agreement will have thirty (30) days from receipt of the Notice of Intent to Process to provide the City with written comments. Time extensions for the written comments may be granted by the City. ff no response is received from a participating entity during the comment pedod, it is assumed that a "no response" implies no comment for documentation purposes. Applicant appeals from the permit decision may be sought from the indMdual jurisdiction. 12 Step 5. Formal City ,,~,~on - The final step in the applicatiL.. ,eview process is formal approval, approval with conditions, or disapproval by the City within the CDC area. If a COE permit, a FEMA conditional map revision or a TWC plan of reclamation is denied the Applicant, the City will not issue a CDC. If approved by the City over the expressed unfavorable opinions of other signatories to the Interlocal Agreement, a written summary of the justifications for the City's action will be attached to the approval action. A copy of the Final Disposition of each CDC application will be provided to NCTCOG for the permanent Corridor records. If no development activities occur by the end of five years from the date of issuance, the applicant may submit a written request within thirty days for up to a three-year extension or the CDC permit shall cease to be valid. The City may grant up to a three-year extension. If no request for an extension is made at the end of the thirty day period, the Applicant must reapply for a CDC permit. Summary project status reports are required to be submitted to the CDC/Floodplain Administrator annually. Any significant changes to the project by the Applicant or the City requires the re-evaluation of the permit and may result in a reapplication. Summary project status reports are required to be submitted to the CDC/Floodplain Administrator annually. Any significant changes to development plans, including changes in State and Federal regulatory programs after a permit is granted, requires the re-evaluation of the permit and may result in a reapplication. Please note that NCTCOG should receive official copies of development activities for the corridor as defined by the Trinity River Corridor Regulatory and Review maps. Any appeals to the CDC process should be addressed to the appropriate CDC permitting authority, (i.e., city) and that authority's permit appeals process. 13 Corridor Development Certific December 1991 General. This applicatlon should be completed according to the guidelines set forth in the Corridor Development Certificate Manual. Information provided by the Applicant herein will be used by the City/County to evaluate this Trinity River Corridor Development Certificate (CDC) This application is public information and will be used by other relevant flood plain regulatory authorities, i.e., U,S, Army Corps of Engineers (COE); Federal Emergency Management Agency (FEMA); and the Texas Water Commission (T~/VC). These and other regulatory agencies may require additional information. If additional space is needed to complete this application, please attach a separate sheet labeled approprietaly. Distrlbljtion. if a Notice of Intent to Process is granted, this data shall be distributed to the following agencies: COE, FEMA, ~/WC; the North Central Texas Council of Governments (NCTCOG); the cities of Arlington, Carrollton, Coppell, Dallas, Farmers Branch, Fort Worth, Grand Prairie, Irving, and Lewisvilla; the counties of Dallas, Denton and Tarrant; the Tarrant County Water Control and Improvement District Number One, end the Trinity River Authority. Applicant's Representative. (identify person knowledgeable of and authorized to respond to questions concerning dam provided by the Applicant) Name: Relationship to Applicant: Address: Telephone: (PLEASE TYPE) Standard CDC Form - Part 1 Section A - CDC Application (To be filled out by Applicant) 1. CDC Applicant: City/County: Property Owner: Engineer: Project Name: Project Size: (total acres)z NCTCOG Map Grid: 2. Location: a. Provide general description of location, including MAPSCO location, street address, and identified impacted water bodies: b.i. Part or all of project is within the CDC REGULATORY ZONE. [] Yes [] No b.ii. Part or all of project is within the CDC REVIEW ZONE. [] Yes [] No If the answer to both of these quatalons is negative, NO CDC PERMIT Is required. 3. Proposed Activity: (check appropriate categodes) [] dredge/channel modification [] swale construction [::] fill I'] levee r"J other (attach explanation) 4. Proposed U~e: (check appropriate categories) [] pr;vate single dwelling(s) [] private multi-dwelling(s) [] public [] commercial j'J industrial [] other (explain) 5. Appllclnt requests i variance to common permit criteria. [] Yes [] No [ Please attach supporting material ] AppllraIfon Is hereby made for · Corridor Developmere Certfficate (CDC). I certify that IInt flailair Wtth the Intofruition mined in application, and that to the best Of my knowledge end belief, this information is true, complete, end accurate. Signature of Applicant or Applicanra Representative / Typed Name / Title Date CDC Part 1 - Continued Se~. J B -- Notice of Intent to Process by L _ , County ('T'o be filled out by CDC/Fioodplain Administrator) 1. CDC Number; Local Contact Person: City/county of: Telephone No: 2. Exempt Category: (check if applicable - additional documentation may be required) r'} maintenance/repair of flood control structures [] bank stabilization activities [] outfell/intake structure permitted under NPDES program [] project is completely outside the CDC Regulatory Zone [] discharge of material for beckfill or bedding for utilny lines with no change to bottom contours 3, Required State/Federal Review: a. FEMA Conditional Letter of Map Revision (CLOMR) [] Yes [] No b. COE Permit required [] Yes [] No c. T~NC Plan of Reclamation required [] Yes [] No 4. COE Hydralogic/Hydraulic technical review completed. (check one) [] Yes (attached) I'] No (explain) 5. Administrative Fthdinge:(cemmentsjconditions) 6. City Action ff Variance is requested. [] granted [] denied 7. Notice of intent: (check one) [] issued [] denied [] not applicable (CDC not required) By my authority under the City/County, I hereby issue and re~ord the Clty/County's findings. 11~is Notice of Intent to Process In no my implie~ that final project approval Will be granted by the City/County. Signature of CDC/Floodptain Administrator / Typed Name / Title Date Section C - CDC Action/Findings {1'o be fiefed out by CDC/Floodplain Administrator) 1. Listing of Commentaries: (written comments on this application were received from:) 2. Summary of Other Permitting Actions: COE Project No: Permit Type: [] issued [] issued w/conditions I"1 denied I'1 no permit required (comments:) FEMA Comments: TVVC Comments: 3. CDC Action: (check one) [] granted I'1 granted w/conditions [] denied 4. Operation and Maintenance Agreement: [] executed (attach copy) [] not applicable Date/initials: 5. 11re CDC Will cease to be in effect: [] five years after the date of issuance it no development activities are undertaken [] DATE: 6. final Findings of Fact: (summer/of City/County's findlngslcomments/~;onditions) By my authority under the City/County, I hereby issue the CIty/County's findings end final Ictlon. Signature of CDC/Floodpiain Administrator / Typed Name / Title Date CDC APPLICANT: 'r3C NUMBER: Standard CDC Form - Pad 2 Detailed Hydrologic/Hydraulic information General, CDC Applicants are requested to provide the following detailed hydrologic and hydraulic information for all proposed projects within the CDC Regulator'/Zone of the Trinity River Corridor. This form and the data provided by the Applicant heroin is a required supplement to the Part 1, Corridor Development Certificate (CDC) Application+ However, in certain cases the City/County may release the Applicant from completing all or portions of this form if the proposed project satisfies specific provisions+ The Applicant is encouraged to schedule e pre- application meeting with the City/County if there are any questions regarding the requirements of the C~//County. This application is considered public information and will be distributed to affected Federal, State, and local governmental agencies, Please be as complete and concise as possible. (To be filled out by Applicant) 1. Site Plan. (a) Please attach a location map (81/2 x 11 ). Plans attached: [] Yes [] No (b) Please attach a general sife plan (81r2 x11). Ransattached: []Yes ['}NO (c) Please a~lach e detailed site plan (see CDC Manual), [] Yes [] NO 2, Hydrologic/Hydraulic Information. Please provide the following data to characterize the hydrologic and hydraulic impam of the proposed project: -- 100 YEAR FLOOD EVENT -- Hydrologic / Hydraulic Impact (measure) Pre-Project Post-Project Change Discharge: Upstream Boundary: cfs, N/A N/A Downstream Boundary: cfs. N/A N/A Channel Velocities: Upstream Boundary: fps. fps. fps, Downstream Boundary: fps. fps. fps. Water Surface Elevation (NVGD): Upstream Boundary: ft. ft. ft. Downstream Bounden/: ft. ft. it. Project Lands in Floodplain: ac. ac. ac. Valley Storage on Project Lands: ac-ft. ac*ft. ac-ft. ~ SPF FLOOD EVENT Hydrologic / Hydraulic Impact (measure) Pro-Project Post-Project Change Discharges: Upstream Boundary: cfs. N/A N/A Downstream Bounden/: cfs. N/A N/A Channel Velocities: Upstream Boundary: fps. fpa. fps. Downstream Bounden/: fps. fps. fp8. Water Surface Elevation (NVGD): Upstream Bounden/: Downstream Boundary: ft. ft. ft project Lands in Floodplain: ac, ac. ac. Valley Storage on Project Lands: so-ft. act ac-ft, CDC PART 2 - CO~q'INUED 3. Flood Slorage/Hydrauli¢ Mitigati~... r~lease idenUfy all flood storage and other hydrolo~,., ,,ydrauJic mitigation areas on the site plan, and describe them in the space below: 4. Habitat/~Net/and Mitigation. Please identify all habitat end/or land resource area used for environmental mitigation purposes on the site plan, and describe them in the space below: 5. OINIritjorl lnd Maintenance. The operation and maintenance of flood water conveyance systems, conveyance alterations, storm water control structures, equipment and appurtenances, and water quality control measures will become the obligation of: (check one) [] City [] County [] Owner ~] other (spe~:ity): The annual/zeal cost, including replacement costs, of operating and maintaining post-project storm water control systems, conveyance alterations, and water quality control measures is estimated to be in current year dollars: 6. Erollon Control Information. Please provide the following data on site erosion control ~nd water quality protection practices, (1) Construction Controls: (describe construction control strategies intended for site erosion control} (2) Post Construction Controls: (describe permanent control strategies intended for erosion control and water quality protection after project completion) 7. Land Cover Information. Please provide the following data. in total acres, to characterize the impacts on current land cover which will result from construction of the proposed project: -- LAND COVER INFORMATION -- Values in TOTAL ACRES Land Uu / Land Cover Claulftcltlon *= Pre-Project Post*Project 100 urban/built-up 200 8gricultutal/pasture 300 rangeland/shrub & brush 400 forest/woodlands 500 water (identify on site plan) 600 wetland (identify on site plan) 700 barfen land/mines & quarries ** Note: Listed land cover types are 'Level I' categodes (100 through 700) defined in accordance wffh the/and use and land cover classification of the U.S. Geological Survey, U.S, Depament of the Interfor. This da~a may be required by the U.S, Army Corps of Engineers and other regulatory agencies. To the ~ of my knowledge, the Informltlon in Part 2 is complete end accurate: Signature of Applicant or Applicant's RepresentatNe / Title / Date ';orridor Development Certi~c~ Exlension Request December 1991 General. This application should be completed according to the guidelines set fodh in the Corridor Development Certificate Manuel Information provided by the Appiicant heroin will be used by the City/County to evaluate the extension of the Trinity River Corridor Development Certificate (CDC). This application is public information and will be used by other relevant flood pEain regulatory authorities (e.g, COE, FEMA and TWC). ff granted. the permit extension applies to the Corridor Development Certificate only. Applicant's Representative. (identify person knowledgeable of and authorized to respond to questions concerning data provided by the Applicant) (PLEASE TYPE) Name: Relationship to Applicant: Address: Telephone: CDC Permit Number: EXplanation for Extension Request Status of Other Related permits / Projects Signature / Typed Name / Title Dcte · CDC/Floodplaln Administrator Action/FIndings Extension Request Granted Yes rn No O CDC/Floodplain Administrator Signature / Typed Name / TItle Date Corridor Development Certificate Applicant City / County Other Agencies NCTCOG Submit Section "A" of I -Determine CDC COE Jurisdictional Adds Proposed CDC Application applicability Review Project to -Obtain Technical Review TRIN -Consider Local Policies proceed 1 or stop ~ . II Regional Review & Comment Tracks Review Support Review Process Issues Section "B" Generally ,~0 Days of each of CDC Form Agency "Notice of Intent to Process" ' I FEMA Review if CLOMR issued · COE Review if Section 404/10 Permit Required Appeals fo Permit Decision will be directed fo the permilling Authority __WC Review if Plan of Reclamation Required Issues Section "C" of If op~,roved, p'ons I CDC Form - I Records City will be provd~d to NCTCOG "CDC Actions\Findings" Process requires Affirmative actions Action _ by the COE, FEt, fA, and rwc to continue If Parrnit gxfenslon I Parrnit - is Needed Approved or Denied Records Submit Application ,m), Approves or Deny Federal &State Permit City/Agency for Extension Extension Request Extension if Necessary Actions (Extension Process - pg.2) Corridor Development Certificate pg.2 Extension Process Continued from pg. 1 Applicant City / County Other Agencies NCTCOG Submit Application em~ Approve or Deny 111 Federal and Stale Perrail Records City/Agency for Extension Extension Request Extension it Necessaryt Actions (within ,~0 days of for Extension for Extension 5fh anniversary (Up to three years) of Permit Section 5.0 RELATED STATE/FEDERAL REGULATORY PROGRAMS This Section is composed of the following contributions from the U.S. Army Corps of Engineers, Federal Emergency Management Agency, and the Texas Water Commission describing an overview of the respective agencies' requirements. 14 "3ARTMENT Of THE ARMY FORT .~TH DIST~.ICT, CORPS OF ENGIN P O BOX 17300 FORT WORTH. TEXAS 76102-0300 OVERVIEW OF THE U.S. ARMY CORPS OF ENGINEERS REGULATORY PROGRAM In 1890, the U.S. Army Corps of Engineers began its regulatory program for protecting navigation on the nation's navigable waterways. In 1972, the Corps began regulating discharges of dredged and fill material into navigable waterways. In 1975, a lawsuit results in the Corps regulating discharges of dredged and fill material in non-navigable waters and wetlands. The state of Texas is divided among four Corps Districts. Refer to the attached map to see which Corps District Office serves you. HOW MIGHT THIS AFFECT YOU? If you are planning to conduct a construction activity in or over a navigable water of the United States, a permit is required in accordance with Section 10 of the Rivers and Harbors Act of 1899 prior to beginning construction. Some examples of past activities that required permits include: dredging activities, boat houses, piers, marinas, and shoreline stabilization. Attached is a list of navigable waters within the Corps' Fort Worth District. If you are planning to place or discharge dredged or fill material into waters of the United States including wetlands, a permit is required in accordance with Section 404 of the Clean Water Act. Some discharges of uredged or fill material are covered by the Nationwide Permit Program found in the Corps regulations at 33 CFR Part 330.5. Those discharges that are not covered require more formalized authorization. Please consult these regulations or call the appropriate Corps office if you would like information on whether your project qualifies for a nationwide permit. You are also welcome to schedule a pre- application meeting with the Corps concerning your project. Navlglble Waters of the United 5tit~ within the Fort Worth D/sutct of th~ US Army Corps of Enginccn For p~x~es of Solos 10 m~b~ you my l. bb~ ~ - F~ .' ~ N~m ~e - F~ ( T~y ~ L ~o G~ - From ~. C~do ~ - F~m · I. Bit Cy~m Kn~o~. ~o~ "' ! FORT WORTH DISTRICT RSGUt..AT(Yrf SI~CTION, CESWT-O TULSA, OK 74121,006~ .... , ~/' ' ' "' ........... -..-;_. _ :- _- - DISTRICI' RIGU:,AIORy BRANCH. ALBUQUERQUE DISTRICT F08C~1580 ~aUOVF,"OUt NM 8~e-~.~ FORT WORTH OISTRICt' Federal Emergency Management Agency Region YI, Federal Center, 800 North Loop 288 Denton, Texas 76201-36~8 OVERVIEW OF THE NATIONAL FLOOD INSURANCE PROGRAM "Between 70 and 80 percent of all natural disasters in the United States involve flooding, and from its earliest days the Federal government has been involved with the peril of flooding. Through re-channeling, or through dams and levees, restricting the flow of waters, as well as through the development of hydroelectric power and irrigation, the Federal government has attempted to ameliorate the effects of flooding. But in spite of all these actions, vast sums of money have had to be expended through the response mechanism of Federal Disaster Assistance. In 1968 the Congress embarked upon a new COurse of action and focused upon ways in which flood damages could be avoided or reduced by making the public aware of its potential exposure to flooding and by providing, through the authorization of a Federal flood insurance program, and incentive to encourage COmmunities to adopt floodplain management ordinances that would mitigate the effects of flooding upon new COnstruction. Taking note of the fact that insurance COverage against the peril of flooding was vidually unavailable in the private sector, the Congress enacted the National Flood Insurance Act of 1968, and authorized the National Flood Insurance Program, which represented a new approach to assisting the victims of flooding an opportunity for property owners to purchase Federal government insurance protection. Because the availability of government flood insurance without hazard mitigation would only have increased the potential for flood damage by enCOuraging unwise COnstruction, FIA was directed under the 1968 Act to conduct studies throughout the United States to determine in each COmmunity the location of areas of special flood hazard and to issue Flood Hazard Boundary (FHBM) and Flood Insurance Rate Maps (FIRM) showing the location of these areas and to notify each community of such identification. Special flood hazard areas are determined with reference to the '100-yea~' flood standard, which is the national standard on which NFIP regulations are based. it is also the standard adopted by virtually every federal agency and most state agencies for the administration of their floodplain management programs. Eligibility for the purchase of flood insurance was made available only to those individuals or COrporations whose insurable property is located within a COmmunity that has agreed with the Federal government to adopt ordinances that will mitigate the impact of future flooding. Participating communities that fail to adequately enforce their floodplain management ordinances may be placed on probation or suspended from the NFIP. A new NFIP program, the 'Community Rating System' (CRS) became effective October 1, 1990. Under the CRS, flood insurance premium credits are available in communities that undertake selected additional activities that reduce flood losses and/or that increase the number of flood insurance policies. STATUTORY AUTHORITY FOR THE NATIONAL FLOOD INSURANCE PROGRAM The National Flood Insurance Program (NFIP) became effective on January 28, 1969, (33FR 17804) and was authorized by the National Flood Insurance Act of 1968, (Title XIII of the Housing and Urban Development Act of 1968, as amended, Public Law 90-448, 82 Slat 476, 42 U.S.C. 4001-4128). The position of Federal Insurance Administrator was authorized by the Urban Property Protection and Reinsurance Act of 1968, (Title XI of the Housing and Urban Development Act of 1968, and the Federal Insurance Administration was established under the Housing and Urban Development Act of 1968 as pad of the United States Department of Housing and Urban Development (HUD). The Secretary of HUD delegated to the Federal Insurance Administrator the responsibility for administering the NFIP. Subsequently, on June 19, 1978, President Cartar forwarded to the Congress Reorganization Plan No. 3 of 1978 (43FR 41493) (which has the effect of a Federal statute). This plan, in addition to creating the Federal Emergency Management Agency (FEMA), transferred the functions authorized and described in the National Flood Insurance Act of 1968 and the position of Federal Insurance Administrator FEMA. The organization of FEMA was further defined in Executive Order 12127, dated March 31, 1979 (44FR 19367) and Executive Order 12148, dated March 31, 1979 (44FR 19367) and Executive Order 12148, dated June 20, 1979. On April 1, 1979, in a notice published in 44 FR 20962, and later codified at 44 CFR 2.64, the Director of FEMA delegated responsibility for the administration of the NFIP to the Federal Insurance Administrator of the Federal Insurance Administrator of the Federal Insurance Administration (FIA), which had become a Directorate within FEMA. John Hall, Chairman ~ B.J. Wynne, III, Commissioner Pare Reed, Commissioner TEXAS WATER COMMISSION OVERVIEW OF TEXAS WATER COMMISSION REQUIREMENTS It is a matter of public policy and State law that the State provide for the conservation and development of the State's natural resources. The Texas Water Commission (TWC) is the state agency with priman/responsibility for implementing the constitution and laws of the state relating to water. Those laws are embodied in the Texas Water Code. The Water Code contains statements of public policy, including but not limited to. The control storage, preservation, and distribution of the State's storm and floodwaters and the water of its rivers and streams for irrigation, power, and other useful purposes; and, the reclamation and drainage of the State's overflowed land and other land needing drainage. Chapters 16, 56, 57 and 66 of the Texas Water Code directly affect the permitting, planning, and accomplishment of projects that will affect the storm and floodwaters and drainage. Chapter 16, titled 'Provisions Generally Applicable to Water Development', applies to all projects, whether proposed by individuals, corporations, or a political subdivision of the State of Texas, unless they are specffically exempted in their enabling legislation. Political subdivision is defined in Section 16.001 as a county, city, or other body politic or corporate of the State, including any district or authority created under Article III, Section 52 or Article XVI, Section 59 of the Texas Constitution. Hence, many different types of special purpose districts may be created, but their projects must comply with Chapter 16. Section 16.236 establishes the prior approval of plans by TWC as the basic requirement for any project and establishes penalties for proceeding on a project without approval. In certain circumstances approval authority may be exercised by other entities with established review standards and procedures considered adequate by TWC, such as communities participating in the National Flood Insurance Program (NFIP). Section 16.236 also established an appeal procedure which allows owners of property located outside the corporate boundaries of a city, town or political subdivision that has approved a project the property owner believes is or may be harmful to his property, to ask the TWC to review the project approval. Sections 16.311-.319 make up Subchapter I of Chapter 16 and are known as the Flood Control and Insurance Act. The Act acknowledges flooding potential in the state and the desirability of making flood insurance available to property owners. The Act designates the TWC as the State Coordinating Agency for the NFIP in Texas and authorizes all political subdivisions of the state to take all necessary and reasonable actions to comply with the requirements and criteria of the NFIP. Together, Sections 16.236 and 16.311-,319 assure that a project is not initiated without careful review by competent authority. After Chapter 16, Water Code Chapter 57 is one of the most important parts of the Water Code regarding projects that affect water in the State. Chapter 57, Levee Improvement Districts (LID), specifies the procedures affecting the creation, operation, and dissolution of LID's. Section 57.091 states that LID's may be created to: construct and maintain levees and other improvements (as defined in 31 TAC 301.2) on, along, and contiguous to rivers, creeks, and streams; reclaim lands from overflow and streams by straightening and otherwise improving them; and provide for the proper drainage and other improvement of the reclaimed land. Water Code Chapter 56, Drainage Districts, specifies the procedures affecting the creation, operation, and dissolution of a Drainage District. Drainage Districts are not created by the TVVC but must submit yearly audit reports to the TVVC. Section 56.111 states that the Drainage District may control and supervise the construction and maintenance of canals, drains, ditches and levees, and other improvements of the District and shall keep them in repair. Water Code Chapter 66, Stormwater Control Districts, specifies the procedures affecting the creation, operations, and dissolution of a Stormwater Control District. Section 66.012 states that a district may be created by the TVVC to control stormwater and floodwater and to control and abate harmful excesses of water for the purpose of preventing area and downstream flooding in all or part of watershed. Section 66.201 lists the general powers of a Stormwater Control District. To achieve the purposes and requirements stated in the Water Code and to provide for due process, the TWC has established procedural rules which are contained in 31 Texas Administration Code (TAC). Two chapters, 31 TAC 281 and 301 have particular relevance to projects under the Texas Water Code mentioned above. Chapter 281 specffies the rules dealing with Applications Processing and Chapter 301 specifies the rules dealing with Levee Improvement Districts, District Plans of Reclamation, and Levees and Other Improvements. The applicable sections of the Texas Water Code, and the Texas Administration Code are too extensive for complete inclusion in this document. However, any person proposing to process an application for a CDC permit must research and comply with appropriate Texas Water Commission requirements. APPENDICES Appendix A APPENDIX A TABLE 1 Hydrologic Baseline Information A. Discharges at Selected Points on Trinity River - Future Conditions With CDC. LOCATION 25 YEAR 1 O0 YEAR SPS* Trinity River below Confluence with Elm Fork 76,400 124,200 274,500 Trinity River at Dallas Gage 76,000 123,700 273,000 Trinity River below Con~uence with White Rock 76.100 120,900 268,500 Creek Trinity River below Dallas Gage 76,100 120.800 267.800 Trinity River above Confiuence with Five Mile 73,500 116,400 255,200 Creek Trinity River below Con~uence with Five Mile 73,500 116,400 255,400 Creek * SPS = Standard Project Storm Please see associated discharge profiles in attached Plates. B. Discharges at Selected Points on West Fork Trinity River -- Future Conditions With CDC. LOCATION 25 YEAR 100 YEAR SPS West Fork below Eagle Mountain Dam 19,000 36,400 68,000 West Fork below Lake Wodh Dam 18,900 35,800 56,000 West Fork above Clear Fork Confluence 18,900 35,700 56,000 West Fork at Fort Worth Gage (below Clear Fork) 33,9(X) 60,200 136,500 West Fork above Con~uence with Marine Creek 33,000 58,600 136,700 West Fork below Confluence with Marine Creek 39,300 67,000 149,000 West Fork above Confluence with Sycamore 39,200 63,900 147,700 Creek West Fork below Confluence with Sycamore 59,000 93,100 178,900 Creek West Fork above Confluence with Big Fossil 43,200 73,900 158,000 Creek West Fork below Con~uence with Big Fossil 64,500 97,900 201,800 Creek West Fork above Confluence with Village Creek 52,200 64,200 184,1 O0 West Fork below Confluence with Village Creek 56,800 164,700 227,600 Highway 360 (R.M. 523) 50,O(X) 85,200 199,600 West Fork above Confluence with Johnson 47,400 81,0(X) 198,500 Creek West Fork below Confluence with Johnson Creek 47,900 82,300 199,500 West Fork at Grand Prairie Gage 47,800 79,600 198,500 West Fork below Con~uence with Big Bear Creek 54,700 88,1 IX) 21 6,300 West Fork above Confluence with Mountain 54,600 56,000 215,600 Creek West Fork below Confluence with Mountain 58,300 90,500 224,600 Creek West Fork above Confluence with Elm Fork 56,100 90.300 224,300 C. Discharges at Selected Points on Elm Fork Trinity River -- Future Conditions With CDC. LOCATION 25 YEAR t 00 YEAR SPS Elm Fork D.A. between Prairie Creek and 6,300 21,000 62,000 Lewisville Dam Elm Fork below Confluence with Prairie Creek 6,900 21,000 62,000 Elm Fork above Confluence with Stewart Creek 12,400 21,000 62,000 (S.H. 121) Elm Fork below Midway Branch Confluence 9,1 O0 21,000 62,000 Elm Fork above Confluence with Indian Creek 8.900 21,000 62,000 Elm Fork below Confluence with Indian Creek 21,1 00 27.400 62,000 Elm Fork above IH 35 E 18,100 24,800 62,000 Elm Fork below Timber Creek Con~uence (At IH 31,600 43,000 77,400 35 E Lower Crossing) Elm Fork below Confluence with Timber Creek 45,100 61,1 00 111,400 Carrollton Gage 38,800 55,000 100,000 Elm Fork below Hutton Branch Con~uence 35.200 49,500 91,500 Elm Fork below Grapevine Creek 35,000 49,800 93,100 Elm Fork below Cooks Branch Con~uence 35,200 50,000 93,500 Elm Fork below Cell A Sluice Outlet 35,500 50,300 93,600 Elm Fork below Farmers Branch Con~uence 35,400 50.400 94,500 Elm Fork below Hackberry Creek Confluence 35,600 51,300 103,500 Elm Fork below Joes Creek Confluence 32,600 48.500 99,400 Elm Fork below Bachman Branch Confluence 35,000 49,900 104,700 Elm Fork at West Fork Confluence 32,400 49,600 102,600 Appendix A (Continued) Hydraulic Baseline Information ~ RECONNAISSANCE REPORT us An'ny Corps of Engineers F,:.'tVVo,'t.D~.~VOLUME II - APPENDICES UPPER TRINITY RIVER BASIN TRINITY RIVER, TEXAS COOPERATIVE INTERJURISDICTIONAL MANAGEME~ COMMON PER;ING PROCE~ TRIN~Y RIVER CORRIDOR AND GREENBELT "-- DALLAS - FORT WORTH METROPLEX MARCH 1990 Spectftc modifications/additions of the Elm Fork storage and conveyance models include: the proposed Royal Lane bridge, the proposed Belt Ltne Road bridge, and a mere complete representation of the upper Elm Fork (upstream of Indian Creek) due to a comprehensive set of data and topographic maps tn this area. LIST OF PROJECTS ("GRANDFATHERED") The following is a list of projects represented in this Reconnaissance Study Existing Conditions hydraulic medels of the Elm Fork and West Fork. Refer to the ftnal TREIS for the exact location of these projects. Where applicable, these projects are also shown on the figures shown tn chapter 4 of the main report. ElmFor~: Hary Kay Las Colinas Stemmons North Industrial District Las Colinas Service Area Royal Lane Reclamation Lakes of LBj Carrollton/Farmers Branch Levee District Irving Levee District No. 2 Belt Line Business Park Fill Project (at Belt Line Road) Riverchase Carrollton Landftll Lakes of Coppell Gateway Reclamation Trinity Mills Business Park Dallas Nurseries Lakepointe Waters Ridge I Huffines Ranch American Container Landfill Farmers Branch Landfill Highland Park Landfill Cormell Riverpark Proposed Royal Lane Bridge Proposed Belt Line Road Bridge Irving Flood Control District No. I Levee (Northwest Levee) West Fork: TRA Wastewater Treatment Plant Irving Landfill Grand Prairie Landfill Carlisle Midpointe (GPMURD project at Belt Line Road) Riverside Arlington Landfill Village Creek Sewage Treatment Plant B - 8 West Fork (Continued): Rtver Trails (Note: project not constructed as of Feb 90) Riverbend Fort Worth Sewage Treatment Plant Twin Wells Golf Course (at Loop I2) C. Brown Estates Bowen Properties Estes Landfill TCSC Landfill Fill Project (at Arlington-Bedford Road) Fill Project (east of Loop 820) Sanitary Landfill (at East 1st Street) NCTCOG The following section is a list of responses, developed by the Hydrology-Hydraulics Branch of the Fort Worth District, to comments from the members of the Flood Management Task Force of the Trinity River Corridor InterJurisdictional Hanagement Program of the NCTCOG. The comments were the end result of a review process of the hydrologic and hydraulic models developed for the upper Trinity River watershed by the Corps of Engineers in the TREIS. Although the responses were submitted to attending members of the NCTCOG at a 1Z September lg8g workshop, they are included herein as additional information regarding technical details of the hydrologic and hydraulic modeling procedures. Please note: Carrollton, Comment 3. At the time the responses were formulated, the Composite Future condition was not being evaluated. Please disregard the reference in the third sentence which did not consider the Composite Future to be applicable to this Reconnaissance Study. DALLAS Concur. The subject cross-sections were truncated at Luna Road in the Elm Fork storage medel and conveyance Bode1. Storage and conveyance were not included in the hydraulic computations east of Luna Road. FAPJERS BRANCH The proposed bridge at Royal Lane has been incorporated in the Elm Fork storage model and conveyance model, The bridge design data and the project drainage study (including an HEC-2 backwater model) was submitted to the Corps of Engineers by Farmers Branch, IRVING C,' -qt 1. Reference letter of the Dallas County Utility and Reclamation District (DCURD). Response to these comments are as follows: B-9 1. The proposed Royal Lane bridge has been incorporated in the Elm Fork hydraulic models (see Farmers Branch response). 2. The Service Center canal and fill was not incorporated in the Elm Fork hydraulic models. However the project area would have a minor effect on the water surface profiles in the immediate project area especially during the rare flood events. Proper representation of the project in the hydraulic models would require additional cross-section data. In the existing Elm Fork hydraulic models, only two cross-sections lie within the project area. 3. Concur. The widened Elm Fork channel was not incorporated in the Elm Fork hydraulic models. 4. The Royal Lane Reclamation Project was incorporated in the Elm Fork hydraulic models per the design plans submitted to the Corps of Engineers. However the 'as-built' plans have not been submitted to the Corps of Engineers. To accurately represent the Royal Lane Reclamation Project, the 'as-built' plans are necessary. We concur with the opinion that a minor change in bottom elevation of the project channel would have a minor effect on the water surface profiles in the project area since the channel through most of the project is wide and deep. 5. The discharges developed in the TREIS for the Elm Fork were based on critical storm centerings in the Elm Fork watershed, not on the West Fork watershed, as stated in the TREIS report. The Corps of Engineers hydrologic coml~uter program NUDALLAS modeled the Elm Fork using 15-minute time intervals. This model covers an area from Grapevine Dam and Lewisville Dam to the mouth of the Elm Fork. The NUIXAL~S program centers the SPF and frequency floods. Therefore, all discharges on the Elm Fork are based on critical storm centerings. The SPF analyses for the larger areas above Grapevine Dam and Lewisville Dam have been adopted from earlier studies which utilized critical storm centerings. 6. The subject project, located on the west side of the Elm Fork between Valley View Lane and Loop 635, was not incorporated in the Elm Fork hydraulic models. Project information such as plans and cross-sections were not submitted to the Corps of Engineers. The existing cross-sections in the Elm Fork hydraulic mK~els in the project area approximate the limits of the subject project. 7. Concur. The Manning's coefficients of roughness values represented in the Elm Fork hydraulic mwxJels in the Las Colthas area were not modified for this Reconnaissance Study. 8. Concur. The Las Coltnas contract plans (Forrest & Cotton, Inc., December 1971) were reviewed and levee elevation corrections made. Comment 2. Concur. The Irving Landfill has been incorporated in the West Fork hydraulic models. Cross-sections along the subject area (station 152+10 to station 226+80) were ~ifted to represent the landfill. The landfill was modeled with a top of fill elevation at 450.0 f~at NGVD. Although elevation 450.0 does not precisely represent B - 10 the "existing" geometry of the landfill, it effectively excludes the landfill froe storage and conveyance computations. Co~men~ 3. Concur. The cross-section in question is station 268+00. The left overbank area ground points have been modified per the topographic map submitted by the city of Irving to the Corps of Engineers. Additional cross-section information may be needed in this area for future studies since it appears the left overbank area in this portion of the West Fork has been modified recently. FORT WORTH Comment 1, Concur. The Riverbend project has been incorporated in the West Fork hydraulic models per the data submitted to the Corps by the project engineer Freese and Nichols. The model represented the "record' design of the Riverbend project and the West Fork to East 1st Street (cross-section 1804+70 to cross-section 2124+30). The HEC-2 data was converted to LRD-1 format for use in the West Fork backwater model. The data was modified to consistently represent storage and conveyance in the subject area. Comnent 2. The entire storage model for the West Fork, from the West-For~Elm Fork confluence to Riverside Drive, has been modified for this Reconnaissance Study. The end result of the modifications has produced a more accurate and refined method of calculating West Fork valley storage. In the subject area (upstream of the Riverbend project at Big Fossil Creek) valley storage has been more completely and accurately computed due to cross-section data submitted to the Corps of Engineers representing the Riverbend Project along with necessary modifications made by the Corps of Engineers. Specifically, cross-sections 1915+10, 1927+00, 1930+80, 1931+20, and 1938+00 include storage in the left overbank at Big Fossil Creek to the Estes Landfill where the cross-sections were truncated. Cross-section ]946+00 includes storage in the left overbank to the railroad and in the right overbank to the Riverbend Levee. Conmment ), The subject project, located east of Loop 820 on the south bank of the West Fork, has been incorporated in the West Fork hydraulic mNxiels. Cross-section data and detailed design plans were not available. However the subject project is small and has an insignificant effect on the water surface profile since the project is located in the right overbank beyond the effective flow boundary of the area. Comment 4A, Concur. The subject project, C. Brown Estates, has been incorporated in the West Fork hydraulic models. Cross-sections 1804+70 and 1812+20 were modified to represent the project. The right overbank of each cross-section was truncated at the fill limit of the project. Storage and conveyance were not included in the hydraulic computations within the project area. B- 11 Comraent 4B. Concur. The subject project, 13often Properties, has been incorporated in the West Fork hydrau]tc models. Cross-sections 2]76+05 to 2243+90 were modified in the left overbank to represent the fill project. The cross-sections were truncated in the left overbank at the project fill limits. Storage and conveyance were not included in the hydraulic computations within the project area. Co~nent 5. Reference Comment ] of letter fro~ Nathan O. Hater. Cross-section 1802+20 has been replaced with cross-section data developed by Nathan D. Naier'Consulttng Engineers in the River Trails I985 project report. The new section represents the fill in the left overbank at the proper station. For this Reconnaissance Study, storage and conveyance were not included in the hydraulic computations within the River Trails project area behind the fill boundary for all frequency .flood events. GRAND PRAZR%E Comment 1. Reference letter of Albert H. Halff Associates. The response to these comments are as follows: 1. Concur. The Irving Landfill has been incorporated in the West Fork hydraulic models. See Irving Comment 2. 2. Concur. The Carlisle project has been incorporated in the test Fork hydraulic ~Klels. Cross-sections 310+50, 340+00, 370+00, and 398+40 were modtftsd by truncating the right overbank at the project limits. Additional cross-sections, 347+50 and 355+00, were added. The data for the two cross*sections originated fro~ a test Fork model developed by Albert H. Halff Associates. The cross-sections were truncated in the right overbank at the project ft11 limit. Storage and conveyance were not included in the hydraulic computations within the project area. 3. The four proposed projects are not included in the test Fork hydraulic models for this Reconnaissance Study. ProJect design data have not been submitted to the Corps of Engineers. 4. Concur. The West Fork storage model and conveyance model in the Bear Creek overflow area has been reevaluated and modified. The Bear Creek overflow area north of Hunter Ferrel Road has been modified to include storage for the lO0-year f"loed event and larger. This area has also been modified to represent the lO0-year effective flow limits. For flood events larger than the lO0-year event, the* overflo~ area has been represented as a conveyance area. The GP~URD project east of Belt Line Road fro~ cross-section 412+20 to 468+00 was modeled to elevation 500 which completely excludes storage and conveyance within the project area. Portions of the West Fork hydraulic models developed for this Reconnaissance Study in the lower portion of the test Fork include data developed by Albert H. Halff Associates with modifications made by the B - 12 Corps of Engineers for consistent representation of storage and Conveyance. S. Concur. Thts co~ent relates to Grand Prairie Comment 4 since the modifications of the West Fork storage model and conveyance model include this area as well. In the area of the West Fork from cross-section 370+00 to S84+00, lO0-year flood effective flow limits were established. This includes the area upstream of Belt Line Road ~o Hardrock Road. Coem~ent Z. Reference Comment 2 of letter from Nathan D. Maier. Concur. Cross-section 884+70 has been ~tfied in the right overbank to represent the Riverside Levee. Cross-sections 837+30, 884+70, 908+40, and 942+00 were truncated in the right overbank at the levee. Storage and conveyance behind the levee were not included in the hydraulic computations. Coem~ent 3. It appears there are a sufficient number of cross-sections to properly model the existing ground in the vicinity of SH 360. No change to the TREIS models was made in the area downstream of SH 360. A split-flow analysis was not developed to model the hydraulics in the area at this time. CARROLLTON Cow~ent 1. The Corps of Engineers have met with Nathan D. Haier Associates coacerntng the unsteady flow analysis model. After review and consideration, we have modified our Puls routtngs for several reaches. The combining point location of Denton Creek and Dudley Branch with the Elm Fork was revised. Dudley Branch was combined below the Indian Creek confluence with the Elm Fork. Denton Creek was combined below the Ttmber Creek confluence with the Elm Fork. Thus, the hydrographs from these areas were slowed down and attenuated due to being routed through additional effective storage. Storage-discharge routing data was added on the lowest reach of Timber Creek above the Elm Fork. Previously no routing was performed. Storage-discharge routing data was added on the lowest reach of Indian Creek above the Elm Fork confluence. Previously no routing was performed. Comment 2. Reference letter of Nathan D. Haier, 27 October 1988. Response to these comments are as follous: 1. See Fort Worth Comment 5. 2. See Grand Prairie Comment 2. 3. The cross-sections in the Westgate Business Center area have been reviewed. The cross-sections indicate a top of fill at elevation 460.0 feet NGVD which is higher than the existing approximate fill elevation of 441.0. The subject project was represented at elevation 460.0 for consistency with the TREIS medeling poltcy; storage and conveyance were not included tn the hydraulic computation wtthtn a project area for all frequency flood events. For this Reconnaissance Study, the subject B - ]3 project was represented at elevation 460.0 in the hydraulic models. An analysis was performed with the Westgate Business Center represented at elevation (41.0. The analysis indicated no change in the water surface profile in the subject area below the lO0-year flood. The Standard Project Flood profile changed tnsignificantly (less than 0.1 foot). 4. Concur. The proposed Belt Line Road bridge has been incorporated in the Elm Fork hydraulic models. The bridge was represented per the bridge design data submitted to the Corps of Engineers by Albert H. Halff Associates. 5. The Riverchase Project has been reviewed and the subject cross-sections (881+50 to g35+70) modified to represent the top of fill at elevation 445.0 feet NGVD. However, the cross-sections were truncated at the project fill limits. The modifications have an insignificant effect on the storage and conveyance computations. Co~m~ent 3. Reference letter of Nathan D. Maier, 26 Septe~er 1988. The letter contains comments regarding the Elm Fork Existing Baseline Model (EBM) and the Elm Fork Composite Future Model (CFM). The CFM comments were not addressed since the CFM is not a part of this Reconnaissance Study. The complete Elm Fork storage model and conveyance mode) has been reevaluated for this Reconnaissance Study. Comments referencing the EB~S have been incorporated in the Elm Fork hydraulic mo~els. ARLINGTON Comment 1. Cross-sections 1330+00 to 1355+80, in addition to other cross-sections in the 9eneral area of the Village Creek Treatment Plant, were reviewed. In this Reconnaissance Study's hydraulic models, cross-section 1330+00 was truncated in the right overbank at the dryin9 beds levee. Cross-section 1355+80 was truncated in the right overbank at the plant levee. Commnt 2, The subject project is located east of the Village Creek Treatment Plant and southwest of the drying beds. The project has been incorporated in the West Fork hydraulic model. However, the project is beyond the effective limits of conveyance in the area and has an insignificant effect on the water surface profile of the area, C.- -~t 3, imperviousness has been incorporated in the HEC-1 model for the West Fork. LEWISVILLE Hydraulics Co~ents, The Elm Fork storage and conveyance models developed in the TREIS have been reviewed and reevaluated. Extensive analysis was performed in the upper Elm Fork area (MK&T Railroad to Prairie Creek). Existing TREIS cress-sections were modified and additional cross-sections were added. Much of the upper Elm Fork modifications originated from data developed by Grahaa Associates as B - 14 indicated in the XEROX Relief Swale As-Built Hydraulic Report dated 1988. A topographic map (1"-200', 2-foot contour interval) was also included in the XEROX report. The topographic map indicated project boundaries in the upper Elm Fork area in detail. The hydraulic analysis consisted of two parts; (1) development of the storage model and (2) development of the conveyance model. Storaqe Node}. A storage mode} of the upper Elm Fork area was developed using existing cross-section data with additional cross-section data developed by Graham Associates. Specifically storage was excluded from the hydraulic comptltations west of the MK&T Railroad and within the project limits of the American Container Landfill, Highland Park Landfill, Farmers Branch Landfill, Cormell Project, Huffaries Ranch, and the Dallas Nurseries project. The subject cross-sections were truncated at the project limit by use of an X3 card. Storage was represented in ineffective flow areas and within the west split-flow area west of the American Container Landill]. Storage downstream of the Lewisvflle Lake spillway above SH ]2] was not inc]uded in the storage model. Conveyance Rodel. Once the storage mode} was properly developed, a conveyance model of the Upper Elm Fork was developed. The conveyance model defined effective flow limits of the area. The effective flow limits were established by inserting X3 cards within the HEC-2 data input at the appropriate cross-section. Conveyance was exc]uded from the hydraulic computations for all frequency flood events in the project areas listed above. A split-flow analysis was performed at the split area around the American Container Landfill. The split-flow analysis balanced the energy gradient upstream of the landfill at cross-section 1418+00. Cross-section 1389+70 was used in the TREIS. The cross-section data representing the split area as developed in the XEROX report was not incorporated in this Reconnaissance Study Elm Fork hydraulic models due to time constraints modeling the complex flow characteristics of the area. However, comparison of the area storage-discharge curves developed tn the TREIS model to the curves developed in the XEROX study tndtcltes similar storage-discharge relationships. Therefore for this level of study, the TREIS existing conditions model was used in this Reconnaissance Study Elm Fork models for this specific area. Hydroloqv C~ewnent$. In reference to the Elm Fork, a NUDALLAS Elm Fork model using IS-minute time'intervals was developed. This hydrologic model was used in the TRE[S and also in this Reconnaissance Study. This model covers an area from Grapevine Dam and Lewtsville Oam to the mouth of the Elm Fork. A one-hour time interval was used for the HEC-1 Trinity River Basin model as developed for the TRE[S and this Reconnaissance Study. This timo'tnterval was sufficient because of the large amount of drainage area (6,275 square miles) covered by this study and the subarea size. Zn this Reconnaissance SLudy, floed hydrographs are printed at more locations within the study area. B - 15 Appendix B Regional Policy "'}sition on Trinity River Co , dor - 1989 Adopted by the Trinity River Corridor Steering Committee and the Executive Board of the North Central Texas Council of Governments The Dallas/Fort Worth metroplex is the largest inland metropolitan region in the country, surrounding a relatively small stream named the Trinity River. To assure adequate water supply to the region's 4 million people, upstream reservoirs have been built on all major forks and tributaries. Thus, the summer flows in the West Fork and Main Stem of the river consist phmanly of highly-treated wastewater effluent, while the Elm Fork conveys mostly lake releases to a Dallas water treatment plant. Long-standing federal plans to construct a barge canal from Fort Worth to the Gulf were abandoned in the eady 1980'S, leading to numerous unrelated requests for federal permits to recl.~m pertions of the flood plaun for commercial and residential development. The Fort Worth Disthct of the U.S. Army Corps of Engineers, which was formed after severe nver flooding in the 1940'S' has completed a three-year regional study of the cumulative effects of alternative development scenarios. Throughout this effort they have worked closely with elected officials and staff from the nine affected cities and three counties through the North Central Texas Council of Governments. The Corps of Engineers indicates that two malor conclusions have emerged from their Final Regional Environmental Impact Statement. The first ~'eemphaszes that a widespread lack of Standard Project Flood (SPF) protection currently exists" throughout the dyer corridor. The SPF flood plain now consists of about 69,500 acres. with 4,400 acres of residential propert,/and 10.000 acres of commerciai/industhel property, Damages to property if a Standard Project Rood were to occur today could approach several billion doitars The second maior Corps of Engineers conclusion is that "different permitting strategies have a measurable and significant impact on the extent of increase of this lack of SPF protection." Under the most extensive development scenano, flood damages could tdple the estimates for the baseline condition, not including the catastrophic effects if the Dallas Roodway levees were breached. However, the Corps of Engineers has stated that it has limited permit authority in the flood plain to affect these scenarios. and that any solutions must come from a cooperative approach among local governments. Since mid4986, NCTCOG has been sennng as convenor and facilifator of affected local governments in pursuit of a COMMON VISION for the Tdnity River Corridor. The Regional EIS provides invaluable information to aid local governments in this quest. The Steenng Committee of elected officials which is guiding the intequnsdictional program has recognized that even under existing developed conditions many citizens and many thousands of acres of land are under the threat of flooding in SPF conditions. Until a major flood control program can be completed to reduce or eliminate the ex,sting flooding threats, the continuing pressure for development of the flood plain must be managed in the most practical and equitable manner possble to at least stabilize current levels of flooding risk. Attention must also be placed on meeting water and other enwronmental quality goals and implementing desired regional public facilities. As a significant next step in its pursuit of a COMMON VISION, the Trinity River Corridor Steenng Committee revises and adopts this Regional Policy Position on Trinity River Corridor - 1989. The Trinity River Corridor is a unique regional resource. The lO0-mile Tdnity River Comdor includes the Standard Project Flood (SPF) flood plain of the Wost Fork, Elm Fork, Msin Stem and malor thbutalies from the reservor dams downstream to south Dallas. The nver comdor is a unique regional resource in the heart of a growing metropiex. Desires to reolajm or preserve it can and will obviously conflict -- there is room in the 70,000 acres of the comdor for both. The river corndor is valuable to all 4 million residents of the region and the millions to com~ Local governments must be the stewards of the Trinity River Corridor. Whatever is done to reclaim or preserve the river cornder will require local government action -- zoning, permits, capitaJ expenditures, maintenance. While other governmental bodies, such as levee districts, several state agencies, and three Federal agencies, have fragmented authority within the nver corridor. local governments are directly responsible for the overall health, safety and weftare of their own citizens. Thus. local governments must take the lead as Stewards of the river corridor. Individual local goals can or achieved th,'ough cooperative n lement. The river corndot encompasses ~, ..arts of at least nine cities anc~ three court, No singae IocaJ government can attain its own goals alone, S~nce actions of upstream and downstream communities will d~rectiy affect them The participating local governments have recognized this even more clearly as they have revtewec~ the Final Regional EIS, and have reaffirmed their desire to pursue a COMMON VISION for the Trinity River Corridor The following policy statements reflect actions to be accomplished by the participating local, state and federal agencies between 1988 and 1990 to stabilize the existing risk of flooding, explore alternatives to reduce this risk. initiate a world-class Trinity Greenway strategy, and continue to improve water and other environmental quality conditions. The participating cities are providing $200,000 to NCTCOG to continue its coordination and technical assistance role, and to facilitate local involvement in the new Corps Reconnaissance Study. A key to successful cooperative management is common permit criteria. A significant finding from the Final Regional EIS is that different local policies for flood plain reclamation can increase or reduce the risk of flooding or the potential for water Quality degradation. Each city in the river comdor currently uses its own set of criteria for permitting a development prolect, which must meet minimum tiood insurance requirements. To assure successful cooperative management, participating local governments are commiffing to use common criteria for permit decisions. Principles for the common criteria have been developed jointly by the local governments and Corps of Engineers in response to the Regional EIS findings. Dunng late 1987, the local governments and the Corps of Engineers spent many hours negotiating principles for common permit criteria that would stabilize the existing threat of flooding while allowing limited flood plain development. The criteria aDDroved in the Corps' Record of Decision are derived from'the Corps' interim criteria. They are intended to be aDDled for the entire flood plan, not just the Corps' jurisdictional area. Cities could still have site-specific requirements as long as they would not conflict with the common criteria, The common criteria will be applied by local governments, the Corps of Engineers, and other statelfederal agencies through a new Corridor Development Certificate process. To insure coordination among all permitting agencies in the use of the common criteria, the Steenng Committee has endorsed a new Corridor Development Certificate (CDC) process, While each city retains development authority within its jurisdiction, a joint process of notification, Corps technical analysis and local government review is performed for each application. To aid permit applicants and assure consistency of interpretation, a criteria manual should be Qeveloped which clearly describes and illustrates the common permit criteria. A computerized Trinity River Information Network is being initiated by NCTCOG to track public and private actions. It is clear from the recent program that there is poor tracking of projects along the corridor and inadequate communication among local state and federal agencies, TRIN will be a computer mapping and geographic information management system mantained by NU/UOG, It will serve as permanent documentabon of permit decisionS, and be used as input by the Corps of Engineers and others to the hyclraulic/hydrclogic computer models, Expanded technical assistance within the river corridor should be provided by the Corps of Engineers. It is extremely important that computer modeling of the nver corndot be performed on a consistent basis so that the impacts of a proposed development activity can be fairly evaJuated under the common criteria. The local governments have provided the Corps with the most up-to-date baseline intormatlon aveulabie, and are agreeing to use the CorDs models in current studies. However, if is recognized that extensive new aerial photography, tofxx:jrapby, cross-sections, and related data is needed to improve the reliability of the computer models for use in permiffing and detailed design studies. A regional review and comment process on major actions is being established. To improve communication among affected local governments, and coordination with state and federal agencies, a Notice of Intent to Process a CDC applr.,at~oo will be dlathbuted by the appropriate city to all other local governments in the corridor, the Corps, FEMA and Texas Water Commission for comment. The city will consider these comments as if makes its deciSon whether or not to grant a CDC. A Trinity Greenway of major ~ linked b,v a re,oional trails syst~ being pursued. Tens of thousands of acres of open space are being preserved within the river corndor with outstanding ;~otential for acfive and passive recreafion. Even if the most extensive development scenano were ~mplemented, the remaining open space acreage would equal more than twenty New York Central Parks. Using TRIN, local parks and recreation professionals will prepare a realistic Trinity Greenway strategy of major parks linked by a regional trails system. Funding prlorifies for implemenfing such a greenway wdl be sougrit from the Texas Parks and Wildlife Department in their 1990 Texas Outdoor Recreation Plan. Studies to identify the causes and solutions to periodic fish kills should be continued. Dissolved oxygen quality in the r~ver under normal flow conditions has improved significantly dunng the last decade, as major wastewater treatment plants have been upgraded. However. fish kills occurred downstream of the region in 1985 and 1986 during peak river flew events w~th low dissolved oxygen levels. The Texas Water Comm~ssmon should Continue its lead role in ccordinating local, state and federal studies to document the causes of these fish killS and to identify realistic and effective solutions. Scientifica~y-sound information on toxic po~utants should be obtained. In the past, limited sampling of river pettom sediments at scattered Sites has found elevated levels of selected toxic pollutants. Several monitoring studies are now underway to determine the levels of selected pesticldes and heavy metals ~n the water and fish. The Tex~s Water Commission should use scientifically-sound technical data as the bas~s for setting any new toxic standards required by federal law. Sites for future regional stormwater detention basins should be preserved. As identified in the Rnal Regional EIS, sites for future regional wet detention ponds should be preserved, since the fish kill studies or the emerging EPA storm water permit requirements on cities may identify a need for such facilities as an alternative to costly ston'nwater treatment. However, the need for tertiary treatment of wastewater effluent by land aDplicafion in the flood plain has not been justified at this time. Particular affention should be given to desired regional public facilities. There are ~mportant regional public facilities that must be protected from potential flooding damages, such as the joint system wastewater treatment plants. New public facilities such as bridge crossings, a potentiaJ parkway, and the RAILTRAN mass transit system must be planned carefully and comply with the common criteria. The Corps is identifying alternatives to reduce flooding risks and provide environmental enhancements in its Reconnaissance Study. During 1988, the participating local governments aided the Corps in obtaining Congressional appropriations of $680,000 to conduct a Reconn-L~--'~nce Study of the Upper Trinity basin. The purpose is to identify problems and opportunities. identify potential solutions, determine whether a federal interest is wananted. identff,/the local sponsor(s). and outline the next steps to be addressed in a Feasbility Study. The Reconnaissance Study began in October 1988 and is expected to be completed in eady 1990. Close coordination is occurring with local governments through the Steering Committee and staff. The full range of nonstructural and structural alternatives should be examined without restrictions by the State. In its studies, the Corps should examine the full range of nonstructural and structural alternatives to reduce flood damages, enhance water and environmental qualities, and provide for recreation. It would be inappropriate for the State Legislature to enact restrictions on the options which could be implemented for the Elm Fork, West Fork or Main Stem. State and Federal funding for the Feasibility Study should be earmarked for FY91 and beyond. It is already clear that there are at least two nonstructural cooperative projects for turther refinement in a Feasibility Study One iS the improvement of the Corps' computer modelS through an extensive data collection effort, so that they can serve as useful tools in the CDC permitting process to stabilize the flooding risk. Interest has also been registered by Dallas, the River Forecast Center and others to explore the benefits of a sophisticated computer- based Flood Warning System. The initial portion of the four-year $5 million Feasibility Study needs to begin in FY91 with 50% federal funding and 50% state and/or local matching funds. NCTCOG Executive Board 1988 Trinity River Corridor Interjurisdic Management Program President "In Pursuit of a Common Vision" Everett Gladcling · Mayo{ Pro Tam. Crty of Green~qlle Designated Local Government Representatives: V~ce PresKJent Jurisdiction Steering Committee Flood Mgmt. Task Force Bed Willisms Mayor Pro Tern. City of Fort Wodh C6y of Arhngton Ken Groves Jero~le F. Ewen. Asst Councilmember D~r of Community 0ev Secreta.~-Treasurer Mertl VmnRavenswaay C~ty of Carroll~on Gary Blanscet Pat Cenuteson Co~ncdrnernDer. C~y of Adt~ngton Councdrnern~er C~ty Engineer Past Premdent City of CODDell Mark Wotle Russell Doyle Joe Reglan Councirnember C~ty Engineer Former Co~ncdrnernDer City of Garland City of DaJlas John Evans Michael H, Askew Dfecto~ Mayor Pro Tern Program Manager John Evtns C~ty of Farmers Branch Calla Lea Davis J.V. Mumv~ki. Jr. Mayo~ Pro Tern. City of DaJias Mayor Pro Tern C~ty Engineer D(fector City of FOrt Worth Bed C. Willlares Glry L Santlffe Ed Gllll~ln Mayor Pro Tern Dir. of PutIc V~3tks Lee Jackson City of Grand Prar~e Ed Gllllgan Dale Powell Mlrgie Wildmop Councdmember of Pubhc Wocks Elks County William J, Pltstlck Adopted by the Trinity River Corridor Steering Committee and the Executive Board of the North Central Texas Council of Goqsfnments on January 26, 1989 and Feb{uary 23, 1989 respectively. Whet is NCTCOG? The Nodh Central Texas Council of Governments is a voluntary association of cities, counties, schod districts, and sl)ecel districts -- estat}/4shed ~n January 1966, to assst local governments ,q planning for common needs, cooperating for mutual benefit. and co0rdinabng for sound regK)nal davit The Courtall of Governments is an organlzabon of, by, and for k3caJ govefrs'nents Its purpose is to strengthen both the indivldua~ and collective power of local governments -- and to heip them recognize regonaJ olX}ortunibes. restive regional ¢}robiems. eliminate unnecessary duplcat~on, and make joint regional decsons. NCTCOG also asssts in developrag the means to implement Noelh Central Texas is a 16-county metroOditan ragson centered around DaMas and Fed Wodh. Currently the Council has 204 rnembes. including 16 counties. 149 cities. 21 independent schod districts, and 18 special districts. The area of the region is appcmamately 12,800 square miles, which is larger than nine states. and the population of the regK~n is over 4.0 million. which ks larger than 29 states. For more Information contact: North CeqtraJ Tex~s Council of ~ts, Department of Env~'onmental Resources F~ O. Drawer COG/616 Six Rags DrWe/A, lington. Texas 76005-5888/(817) 640-3300 (metro) D~e~her 15, 1988 RE~DIIIrlC(~ FOR A JOINT ~Illl'n[ R/VER ~ DEV~nPM~!T cu~'L~'iCA~E PRCX't~ 2. ~.~nat, in ac~u=danoe with the Draft SLAL,~ of Prir~ples. applicalnions for Trinity River Corrzdor flocd plain madificar. ians (as defined in the Draft Statemen~ of Principles) are ~o be processed in the follcwlng manner: a. applicatiars for Trinity River Curridor flood plain n~difica~icms will be in/t~l]y filed with the DDC~LL Flood Plain i~m~nis~ra=or: b. the Lacsi Flood Plain J~m~ni~L~'atar will dcnm~fc the fj_lir~ of an applicatim for fload plain m~ ficatian by providing the app]icant with a "Stav~l Notice of Intent to Process." (~hi~ joint ~ be approved by the S~--r~ng n-,,,,itt~); c. the "Starv~i Notice of Intent to _Pr~" w~11. d~n~_m~nt the citT's fl~cd plain, and wl]l serve as notice 8rid ve~ificatim that the Lacal revieding the coo~dirntian, w~]l 8~ribute u.pies of the ,,Starv~i Notice of Int~L to ~,, to the U.S. Azmy Gi~ of ~, the F~n~?'~l ~m~gen~r Manag--,~:L J~jeilcy (FEMA), the Tees Water _n ..... i~icsl, the t~elve e. the U.S. Azmy C~i~ of Enp~s wi]] refuse to aural a Trinity River Carridcw p"~m~t applicaticzl which does not inal,~ a copy of the )-~ water n-,-,,~in~ arit other pezmitting a~j~ies ~LUv'ide a shanty of their p~m~t actires amVor fh~rcjs to the lom~ Flood Plain ~tm~nistrat~r (and the NCIII~) to a~ist the J~lm~nistratar with p~uperly 5. ~lat the North C~L~al Texas Caunail of Gove~--,Ls m~ntain a u~ed trackir~ ~ of the ,'Sta~h~ ~kti~ of Intent to Pron~" a~d 6. ~lat the District Engilleer of the Fort Worth District Cu~ of Engineers, the Regional Direct~ of F~MA Regial VI, and the Ev~_ive Director of tile r ........ ~I~ alf~natives which w~]l fulfill, to gresf~-t exl~nt possible, the j3rte_nt of this resolutic~l. ~Lir~ city a~mcil/o-,-,~i~me~ a~rt ~ti.'m. RECOED OF DECISION ~EGIONAL ENVIRONMENTAL IMPACT S~aTEMENT TRINITY RIVER AND TRIBUTARIES I. Introduction Since its early history, tb~ U-S. Army Corps of Engineers has played an important role in the development of the nation's water resources. Originally, this involved construction of harbor fortifications and coastal defenses. Later duties included the improvement of waterways to provide ave- nues of com~rce and reduce flood hazards. An important part of its mission today is the protection of the nation's waterways through the administration of the Regulatory Program. The Corps is directed by Congress under Section 10 of the Rivers and Harbors Act of 1899 (33 USe 403) to regulate all work or structures in or affecting the course, condition, or capacity of navigable waters of the United States. Section 9 (33 USC 401) directs the Corps to regulate the construction of any dam or dike across a navigable water of the United States. The intent-of these laws is to protect the navigable capacity of waters important to interstate commerce. Additionally, the Corps is directed by Congress under Section 404 of the Clean Water Act (33 USC 1344) to regulate the discharge of dredged and fill material into all waters of the United States, including adjacent warlands. The intent of this law is to protect the nationts waters from the indiscrimi- nate discharge of material capable of causing pollution, and to restore and maintain their chemical, physical, and biological integrity. Because the District Engineer's decision to issue or deny a permit under these la~s is a significant Federal Action, various other statutes, principally Public Law 91-190 (the National Environmental Policy Act, or NEPA) come into play. Among other things, NEPA requires the consideration of the direct, indirect, and cumulative impacts of an action (40 CFK 1508.25(C)). Late in 1984 and early in 1985, it became apparent that numerous unre- lated development projects ware Being proposed along the Trinity Pdver and its tributaries in Dallas, Denton, and Tarrant Counties, Texas. Most involved modification of the river channel and/or flood plain in some form or another, and most required a Corps of Engineers perm/t as a result. Because, indivi- dually or cumulatively, these projects ware felt to have the potential to compromise the existing protection afforded to flood plain residents, because of perceived impacts to wetlands and other natural resources, and hecause of competing public demands for other uses of the river channel and flood plain, the District Engineer determined that it was necessary to develop a regional perspective in order to properly evaluate the impacts of individual permit decisions in accordance ~rlth the spirit and intent of NEPA and other appli- cable laws. The Draft Regional Environmental Impact Statement (EIS), published in May 1986, analyzed a number of scenarios which were specifically designed to iden- tify possible, significant cumulative impacts associated w~th different per- mitting strategies for the Trinity River flood plain. In addition to developing a baseline condition, it exandnod three groups of conditions based on a) maximizing environmental quality, b) ultimate implementation of the Federal Emergency Management Agency's (FEMA) minimum criteria for the flood insurance program, and c) maximizing economic development. The results of the Draft Regional EIS indicated strongly that there are potential cumulative impacts associated with individual flood plain develop- ment projects which are both measurable and significant. Additionally, the Draft Regional EIS indicated that the permitting approach adopted by the Corps of Engineers had the potential to have significantly different impacts on a number of regional parameters, especially flood hazards. Even though the ana- lyses were not complete, and the public comment on the Draft Regional EIS indicated that there was much work to follow, the implications to the ougoing Regulatory Program could not be overlooked. In response to this, the Corps formulated a set of interim criteria to be in effect until the Record of Decision was rendered. Many of the comments received on the Draft Regional EIS indicated that the slate of alternatives analyzed did not represent a realistic approach to regu- latory strategies. In many cases, the predicted results were publicly unac- ceptable. Two important examples include the overtopping of the Dallas Floodway levees under two of the scenarios, and a substantial downstream shift in the Dissolved Oxygen 'sag" resulting in noncompliance with State Water Quality Standards in the reach below the Trinidad gage. After careful analy- sis of the public and agency input, several new scenarios were formulated for analysis iu the Final Regional EIS. In addition to updating the baseline, three scenarios, representing the same three broad categories that had been previously addressed, were deve- loped. Many people suggested that the Maximum Development scenarios analyzed in the Draft Regional EIS were too extreme, either because they conflicted with an ongoing project, or because levees were physically impractical in some portions of the flood plain. In response to this criticism, we agreed to replace them with a "Composite Future" scenario. Each city was tasked to pro- vide the North Central Texas Council of~Governments (NCTCOC) a delineation of the "must likely" limits of maximum encroachment within their jurisdiction. NCTCOG compiled each city's individual prediction and presented the resultant set of maps to local staffs and local elected officials before providing them to the Corps for analysis. The Modified Floodway scenario of the Final Regional EIS replaced the floodway-based scenarios of the Draft Regional EIS as a representative compro- mise between maximum (realistic) development and maximum (realistic) environ- mental quality. In this scenario, the Corps defined the geographic limits of a drainageway incorporating the FEMA concept with significan~ technical variations. For the third scenario, the Corps revised and represented a Maximum Environmental Quality scenario, hydraulically identical to the revised baseline because it incorporated no additional flood plain projects except water quality, recreation, and wildlife enhancements. Of the scenarios, or alternatives, examined in the Final Regional EIS, this is the environmentally preferred alternative. The extensive coordination and public involvement characteristic of the Regional EIS process continued during the c:omm~nt period on the Final Regional EIS, which extended from its release on October 22, 1987, through January 31, 1988. During this period, I held a public meeting at Lamar High School at which eleven people submitted statements. My staff actended in excess of twenty meetings with local government staffs, public agencies, and citizen groups. In addition, sixty-six written com.~nts on the Final Regional EIS were received. II. Discussion of Issues and Factors Most of the formal public comment and discussion with local governments centered on three general issues: the appropriate level of flood protection (100-year vs. SPF), the level of accuracy of the hydraulic and hydrologic ana- lyses displayed in the Regional EIS, and the issue of equity as it pertains to governmental regulation. "Benefits" and 'costs" of an action, whether it be a proposed project or a proposed regulation, do not always occur to the same group of people, let alone in the same order of magnitude. The definition of the "public interest" which is at the heart of the Regional EIS calls for an assessment of the tradeoffs inherent between public demands for enhanced environmental quality in the river corridor and for its use for needed public facilities, and economic development and the rights of private landowners. A major concensus achieved through the review of the Final Regional EIS is that additional regional increases in flood hazards for either the lO0-year or Standard Project Flood are undesirable, and that the thrust of flood plain management, in the short term, should be to stabilize the flood hazard at existing levels through regulation. Future efforts on the part of beth the Corps and local organizations may be required to reduce flood hazard over the long term. The Regional EIS is probably the most comprehensive such study done in the United States. It has highlighted the need for planning for the region and cooperation among the governmental entities along the Trinity River corri- dor to achieve quality development. The document was developed for the sole purpose of establishing a permitting strategy for the Trinity River and its tributaries. It does not contain a techffical baseline that will remain current over time and is not to be used as a design document. Design decisions requiring water surface predictions based on critical storm cen- terings, and which are sensitive to valley storage computations, must be based on detailed site-specific engineering analyses. Other site-specific public or private flood con=rol management decisions should likewise be based on current technical analyses. Further, flood insurance da=a mast be obtained from the FEMAand not from the Regional EIS. Neither the Regional EIS nor this Record of Decision encroaches upon the responsibility of design engineers or the authority of local gover-m~nts. The Regional EIS, i=s public review, and this Record of Decision serve only to establish and document the "best overall public interest' as l= applies to the Trinity B/vet and its tributaries. It remains the responsibility of design engineers to perform competent work in accordance with professional design practices. Permit applicants which proposed flood plain modifications and/or site-specific flood control structures will need to satisfy review agencies as to the reasonableness of design assumptions. Throughout the development of this Record of Decision, the Corps has worked closely with the NCTCOG to insure consistency with their COMMON VISION program. The criteria listed below for the West Fork, Elm Fork, and Main Stem are consistent with the Statement of Principles for Co.~w,n Permi= Criteria sub- mitted by the Steering Committee of local government officials. Because of the massiveness of this undertaking and the importance of its impact on future growth, the comments from the cities and other governmental entities have been carefully considered. III. Decision Based on my consideration of the data developed and presented in both the Draft and Final Regional EIS's and my careful consideration of all public input, I have determined that, for the purposes of the Regional EIS study area, my Regulatory Program will be henceforth based on the following criteria. The baseline to be used in analyzing permit applications will be the most current hydraulic and hydrologic model of the specific site in question. The burden of proof of compliance with these criteria rests with the permit applicant. Variance from the criteria would be made only if public interest factors not accounted for in the Regional EIS overwhelmingly indicate that the 'best overall public interest' is served by allowing such variance. A- Hydraulic Impacts--Pro]ects within the SPF Flood Plain of the Elm Fork, West Fork, and Main Stem. The following maximum allowable hydraulic impacts will be satisfied, using reasonable judgment based on the degree of accuracy of the evaluation, and using cross sections and land elevations which are representative of the reaches under consideration: 1- No rise in the 100-year or BPF elevation for ~he proposed con- dition will be allowed. 2- The maximum alloyable loss in storage capacity for 100-year and SPF discharges will be 0% and 5Z respectively. 3- ~tlterations of the flood plain may not create or increase an ero- sive water velocity on-or off-site. 4. The flood plain may be altered only to the extent permitted by equal conveyance reduction on both sides'of the channel- B. Hydraulic Impacts--Tributary Projects. For tributaries with drainage areas less then 10 square miles, valley storage reductions of up to 15Z and 20Z for =he lO0-year and Standard Project Floods, respectively, will be allowed. For tributaries with intermediately-sized drainage areas (10 square miles to 100 square miles), the maximum valley storage reduction alloved will fall betvest OZ and 15% for the 100-year flood and 5~ and 20Z for the Standard Project Flood. Increases in water surface elevations for the lOO-year flood will be limited to approximately zero feet. Increases in water surface eleva- tions for the Standard Project Flood will be limited to those ~fnich do not cause significant additional flooding or damage to others. Projects involving tributary streams with drainage areas in excess of 100 square miles will be required to meet the same criteria as main stem projects (see "A' above). C- Cumulative Impacts. The upstream, adjacent, and downstream effects of the applicant's proposal will be considered. The proposal will be reviewed on the assumption that adjacent projects will be allowed to have an equitable chance to be built, such that the cumulative impacts of both will not exceed the common criteria. D. Design Level of Flood Protection. The engineering analysis will include the effects of the applicant's proposal on the 100-year and Standard Project Floods and sho~d demonstrate meeting FEMA, TeA~S Water Commission, and local criteria, as well as Corps, for both flood events. 1. For levees protecting urban development, the minimum design cri- terion for the top of levee is the SPF plus 4-0, unless a relief system can be designed which will prevent catastrophic failure of the levee system. 2. For fills, the minimum design criterion is the 100-year elevation, see above, plus one foot. E. Borrow Areas. The excavation of "borrow" areas to elevations lower than the bottom elevation of the stream is generally hydrologically unde- sirable. The volume of such excavations, above the elevation to which the area can be kept drained, can be considered in hydrologic storage computations. F. Preservation of Adjacent Project Storage. The applicant will be required to respect the valley storage provided by adjacent projects by ensuring that their hydraulic connection to the river is maintained. If the project blocks the hydraulic cunnection of the adjacent project, then the applicant will be required to provide additional valley storage to offset the loss caused by the blockage of the hydraulic connection. G. Special Aquatic Sites. Value-for-value replacement of special aquatic sites (i.e. w~tlands, pool and riffle complexes, mud flats, etc.) impacted by non-~ater dependent proposals ~r~ll be required. These criteria will be used by the Corps for the express purpose of eva- lua=ing new perm/t applications received subsequent to the effective data. They will not be used to reevaluate any flood plain project already constructed or permitted. They apply to perm/t applications from public agen- cies as well as private sector applications. In addition to the criteria discussed above, the following guidelines will be used by my staff in eva- luating perm/t applications: - A. Runoff. Site drainage systems should m~nimize potential erosion and sedimantation problems both on site and in receiving water bodies. B. Habitat M/tigation. A standardized, habitat-based evaluation method should be used to evaluate the impacts of the applicant's proposal to fish and wildlife resources. Guidelines for the quality and quantity of m~tigation are as follows: 1. Category 2 resources--habitat of high value vhich is scarce, or is becoming scarce in the ecoregion--~o net loss of habitat value. Category 2 resources in The study area include vegetated shallows, riffle and pool complexes, and riparian forests, as well as wetlands (see above for mitigation of wetlands). A buffer strip of natural vegetation 100' feet wide on each side of the channel for main stem projects, and 50* feet for tributaries, should be maintained. 2. Category 3 resources--habitat of medium-to-high value that is relatively abundant in the ecoregion--~o net loss of habitat value while mini- mizing the loss of the habita~ type. (This means to reduce the loss of the habitat and compensate the remainder of loss of habitat value by creation or improvement of other Category 2 or 3 resources.) Category 3 resources in the study area include deep water, native rangeland, upland forests, and upland shrubland. 3. Category 4 resources-habitat of low-to-medium value---mitigation should be to minimize the loss of habitat value, which can be accomplished by avoidance or improving other habitat types. Category 4 resources in the study area include cropland and improved pasture. C. Cultural Resources. Cultural resources, including prehistoric and historic sites, w~lI be identified and evaluated according to National Register of Historic Places Criteria. Identification procedures may involve literature review, pedestrian survey, and excavation to identify buried cultural materials. Sites which are eligible for inclusion in the National Register of Historic Places will be treated by measures which range from avoidance, to preservation in place, to mitigation through excavation. D. Other Regional Needs and Plans. Consideration will be given when evaluating permatt applications of the proposal's impact on regional facilities which have been identified as important through the Regional EIS process. These include, but are not limited to, a linear hike/bike system linking large flood plain parks throughout the Metroplex, the Trinity Tollway, and sites for regional stormwater detention basins. (Specific locations and plans for these facilities will continue to evolve through coordination with NCTCOG and local governments.) Applicants will be urged to design projects which do not preclude future implementation of these regional assets. It is my conclusion that the criteria and guidelines set forth above represent the best available definition of the 'overall public interest,' taking into account the rights of individual landowners and the direct, indirect, and cumulative impacts of individual actions under my purview. Further, I conclude that these policies represent all the practical means known to me to avoid or minimize environmental harm within that framework. This document will therefore provide the specific framework ~ithin which we will operate the Fort Worth District's Regulatory Program within the Regions! EIS study area- JOHN E- SCHAUFELBERGER Colonel, Corps of Engineers District Engineer Date: ~ STATF_IqENT OF PRINCIPLE' FOR COi~!ON PERMIT CRII~RIA TRINITY RIVER CORRIDOR Reviewed by Steering Committee on January 28, 1988 1. WHAT IS THE PURPOSE OF THIS STATEMENT OF PRINCIPLES ? The Steering Committee of elected officials for the Trinity River Corridor Program, and the NCTCOG Executive Board, have adopted an "Interim Regional Policy Position on Trinity River Corridor." It calls for a cooperative management program using common permit criteria which are derived from interim criteria now being applied by the U.S. Army Corps of Engineers, Fort Worth District in their permitting process. It also calls for expanded technical assistance by the COE and a regional review and comment process for major actions. This Statement of Principles represents the best attempt at a regional consensus on permit criteria within the 90 days available for response to the COE Final Regional Environmental Impact Statement for the Trinity River. It was developed by the Staff Task Force through seven drafts, with input from the NCTCOG staff, COE, other governmental agencies and private sector representatives. A significant finding of the Final Regional EIS is that different local policies for flood plain reclamation can increase the risk of flooding or the potential for water quality and environmental degradation. The nine participating cities have expressed their support for a cooperative management program whereby each city still retains development permit authority within its jurisdiction, but bases its permit decision on a set of common permit criteria. It is the express purpose of this cooperative process to satisfy the requirements of the Federal Emergency Management Agency and the Texas Water Commission regarding city flood plain permit actions within the Trinity River Corridor, and to effect close coordination with the U.S. Army Corps of Engineers and other state or federal agencies which have their own permit processes. For purposes of this document, the Trinity River Corridor includes all of the area within the Standard Project Flood flood plain of the Trinity River West Fork, Elm Fork and Main Stem as defined in the Revised Baseline Future Discharges scenario of the Final Regional EIS, approximately 70,000 acres. The upstream and/or downstream boundaries of this corridor need to be expanded, since the City of Fort Worth has requested that it begin at the upstream dams rather than Riverside Drive, and the City of Dallas has previously suggested that it extend further downstream. Page 1 of 8 2. WitAT IS A CORRID(v' nEVEL(~oMENT CERTIFICATE (CDC) ~ To distinguish it from other requirements, the development permit within the Trinity River Corridor to be issued by a city will be referred to as a Corridor Development Certificate (CDC). It is a written authorization by a city which allows property to be "developed" within the city's jurisdiction in the Trinity River Corridor, in compliance with the con~non permit criteria presented later. The CDC will include, as a part thereof, the application and all documents supplied in support thereof and the approval by the authorized agent of the city together with any conditions thereto. Any public or private development within the Trinity River Corridor must obtain a CDC prior to start of construction, unless specifically exempted as discussed below. [NOTE: The definition of "start of construction" has not yet been determined as noted in the last section of this document.] Consistent with the requirements of the Federal Emergency Management Agency under 44CFR59, a development means "any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations." To assure consistency with Texas Water Conmnission requirements under 31 Texas Administrative Code, development also includes "any levee or other improvement" as defined by Section 301.2 of the Code. A development by a city itself within the Trinity River Corridor will be treated like any other application for a CDC, and will undergo the COE permit process if applicable or the regional review and comment process presented later. The application will then be acted upon by the City Council (rather than a staff person who perhaps prepared the application}. If a development can show in writing that it meets any of the conditions below, it may be exempted by the city from the local permit process. [NOTE: the applicant should still check with the Corps of Engineers, FEMA and the Texas Water Commission to determine if the development is subject to specific permit requirements by those agencies.] This written exemption will be maintained on file by the city and be provided to NCTCOG for the permanent records. EXEMPTIONS: a. ordinary maintenance of any flood control structures. b. outfall structures and associated intake structures where the outfall has been permitted under the NPDES program. c. discharge of material for backfill or bedding for utility lines provided there is no change in bottom contours and excess material is removed to an upland disposal area. d. bank stabilization activities meeting Corps of Engineers Section 404 Nationwide Permit criteria under 33CFR330.5(13). e. property which is (1) completely outside the lO0~year flood plain as defined by the Revised Baseline Future Discharges scenario of the Final Regional EIS, and (2) has no COE jurisdictional areas as determined by the Corps of Engineers in writing. Page 2 of 8 3. tlAT ZNFORNATZOt ]LD BE SUBMITTED [N A CDC API TIOII ? An application for a CDC wil] be made on standard forms furnished by the city or facsimiles thereof, and be signed by the owner of the property or appropriate agent. To insure that all proposed developments are afforded a complete and consistent level of analysis, the application will include, but not be limited to: a. Project Plans b. Hydrologic Data c. Hydraulic Data d. Elevation - Storage - Discharge Data e. COE Jurisdictional Review f. Resource Data g. Maintenance and Operation Data More detailed descriptions of these requirements are presented below: a. Project Plans. Project plans would be submitted as part of the CDC application, at a scale which provides adequate detail of the whole project as well as individual features of the project. The plan should show the location of the Regulatory Floodway (FEmUr) and the layout of cross-section's used in the hydraulic model. Proposed changes to the Floodway should be clearly shown. b. H drolo ic Data. Design discharges for the lO0-year and SPF storm s~ould ~e based on urbanization consistent with the Revised Baseline Future Discharges scenario of the 1987 U.S. Army Corps of Engineers' Final Regional Environmental Impact Statement; Trinity River and Tributaries (EIS) or supplemental EIS data provided by the COE, which- ever is higher. The applicant should clearly identify these design discharges, including source and date. ]NOTE: It is imperative that property owners, developers and policy makers understand that the "SPF" discharges in the Final Regional EIS are applicable only for the Elm Fork and the Main Stem of the Trinity River. Critical storm centerings were not applied to the West Fork. Therefore an equivalent level of analysis (i.e. true SPF discharges) is lacking for the West Fork segments of the Trinity River. Representatives of the U.S. Army Corps of Engineers have indicated they may develop a supplement to the Final Regional EIS which would revise the SPF discharge figures for the West Fork. In the interim, this lack of an equivalent level of analysis for segments along the West Fork warrants a conservative respect for the SPF values contained in the Final Regional EIS. Actual SPF discharges along the West Fork will predictably be greater in magnitude.] In conjunction with the common policies described herein, the Existing Condition Future Discharges of the Final Regional EIS (as supplemented by the COE) are reflective of a watershed with modest stability in future discharges. However, future discharge corrections will undoubtedly be required. For consistency in permit review and evaluation of design requirements, revisions to the discharges contained in the Final Regional EIS should be scheduled and coordinated among the affected jurisdictions. Page 3 of 8 c. Hyorau)ic Data. Water surface elevations at upstream middle and do~lstrP~m ends of project (existing and with projectl for lO0-ye~r and SP ~charges consistent with the sed Baseline Future Discha, · should be provided with the , application. Hydraulic calculations should be continued for a distance great enough upstream and downstream of project to verify flow elevations are not raised by the proposed hydraulic modifications. In all cases, the best available data on water surface elevations should utilized. Printouts and plots from an approved hydraulic model (e.g. HEC-2) of cross-sections for existing and with-project conditions should be part of the CDC application. Water surface profiles for lO0-year and SPF floods for existing and with-project conditions should also be included. The number and location of sections should be adequate to describe and support documented computations. discharge .ata li.e.. {1: Fi,al Regio,al Revised Baseli,e Future Discharges w/supplements in combination with the most reliable elevation data available} for design and with-project conditions should be developed: o within the project borders alone; o considering full cross-section widths across the river or creek; and o show percent of change in valley storage capacity. Storage change is to be considered "on site" (i.e., within upstrean and downstream limits of the project). Computations of the change in storage capacity should apply to the SPF flood plain as identified in the Final Regional EIS, irrespective of revised flow elevations possibly derived from an additional backwater analysis of supplemental SPF discharge information. e. COE Jurisdictional Review. Applicants should provide written correspondence from the Corps of Engineers indicating whether Corps jurisdiction applies to the project area [NOTE: a formal determination on the application itself occurs at later step in the CDC process.] f. Resource Data. Applications should include at least the following information on environmental/cultural resources: {1) engineering and environmental resource data which tabulates the impact on land cover t3q}es and habitat units; and (2) any plans for erosion control, general landscaping, or other practices to minimize potential water quality and other environmental impacts. Projects areas which are within COE jurisdiction will also need to provide identification of mitigation required for loss and/or alteration of high value habitats. Development which proposes to relocate or alter a natural channel should also submit more detailed environmental data and a stream rehabilitation program as outlined in the detailed design criteria manual {to be developed}. g. Maintenance and Operation Data. An estimate of annual maintenance and operation costs for the hydrologic/hydraulic aspects of the project should be provided. Parties responsible for costs associated with maintenance and operation in perpetuity for the "as designed" condition should be clearly identified. If maintenance is to be accomplished by an agent other than the community, a legal provision for conmnunity monitoring and backup maintenance is required. Page 4 of 8 4. t. IAT C01140N PEP' ~ CRIiLKIA SHOULD BE MET ? The following ~mmon permit criteria describe a ~onsistent design level of protection which should be met for all CDC applications, unless granted a variance. A detailed design criteria manual will be developed to assist applicants. The applicants for a CDC would be required to provide sufficient detailed information to document criteria compliance. a. Hydraulic Impacts. The following maximum allowable hydraulic impacts should be satisfied using cross-sections and land elevations which are representative of the reaches under consideration: o Flow Elevations. No rise in the 100 year or the SPF flood elevation for the proposed condition should be allowed. The storage loss calculations should be based on the flood plain elevations of the Revised Baseline Future Discharges scenario of the Regional EIS o Velocities. Alterations of the flood plain may not create or increase an erosive water velocity on or off-site. o Conveyance. The flood plain may be altered only to the extent permitted by equal conveyance reduction on both sides of the channel. b. Cumulative Impacts. The upstream, adjacent and downstream effects of the proposed project should be considered. The proposed project should be reviewed on the assumption that adjacent projects can have an equitable chance to be built - such that the cumulative impacts of both will not exceed the common criteria. Hydraulic data {e.g. HEC-2 modeling with blocked off conveyance) should be supplied to show the impacts of adjacent developments. c. Resource Guidelines. Guidelines for measuring and evaluating environmental and cultural impacts will be specified in the detailed design criteria manual (to be developed). d. Design Level of Flood Protection. For all developments, the engineering analysis should include the effects of the proposed project on the lO0-year and SPF floods (based on the with-project design discharges using urbanization consistent with the Revised Baseline Future Discharges of the Trinity River Final Regional EIS) and should demonstrate meeting FEMA, COE, TWC, and local criteria for both. Minimum design criteria should include: o For levees, a minimum design criterion for top of levee should be the SPF elevation plus 4.0 feet of freeboard. o For fills, a minimum design criterion should be lO0-year discharge elevations plus one foot or more of fill freeboard. To provide more protection, a higher fill elevation may be required by local ordinances. o For structures on fill, local ordinances should require minimum floor elevations to be set to at least two feet above the lO0-year discharge elevations. Page 5 of 8 e. Excavat of "Borrow" Areas. The exca ~n of "borrow" areas to ~o~,s lower than the bottom elevatioml of the stream is generally considered hydrologically undesirable. The volume of such excavations above the elevation to which the area can be kept drained can be considered in hydrologic storage computations. Excavation or fill shall not be allowed closer than 100 feet to the channel banks. f. Preservation of Adjacent Project Storage. The developer shall respect the valley storage provided by adjacent development projects by insuring that their hydraulic connection to the river is maintained. If the project blocks the hydraulic connection of the adjacent project, then the developer shall be required to provide additional valley storage to offset the loss caused by the blockage of the hydraulic connection. 5. WIU~T ARE THE STEPS IN lltE CDC APPLIC. ATION PROCESS ? There are five basic steps in the CDC application review process as depicted in the accompanying chart and summarized follows: 1. Determination of Applicabilit~ by City - Does the city have jurisdiction regarding this application? Is ~t within the Trinity River Corridor? Is it exempted from the process? If the city has jurisdiction for the development, the review process proceeds. If not, the applicant is advised accordingly by the city's designated contact person in writing. 2. Hydraulic/Hydrologic Technical Analysis Review by COE - The Fort Worth District staff of the Corps of Engineers will perform the hydraulic/ hydrologic technical analysis review required by the common permit criteria in coordination with the city and the applicant. findings within its own time frame. If the city decides to deny the application at this point, the process ends. If the city decides to continue the process, then it will assure that the application is complete, assign a CDC identification number, and provide the full application to the COE for jurisdictional determination, to FEMA if a conditional map revision is required, to the Texas Water Commission if their jurisdiction applies, and to NCTCOG for incorporation into the tracking system. 4. Parallel COE, FEMA, TWC and Regional Review - If the application is subject to COE permit jurisdiction, then the public notice and review/comment process will be initiated by the COE (including the other affected local governments). If the application is not subject to COE permit jurisdiction, then the city will distribute a notice and materials directly to the other cities/counties in the corridor. The FEf4A and TWC processes will occur simultaneously If under COE jurisdiction, the COE will decide whether to issue its permit and so notify the city {and applicant). Likewise, FEMA will notify the city regarding any requested conditional map revision, and the TWC for any plan of reclamation. Written comments from other cities/counties will be~ provided to the city. Page 6 of 8 5. Formal Ci~ :tion - The final step in the lication review process is formal appro, approval with conditions, or approval by the city of the CDC. If a COE permit, a FEMA conditional map revision or a TWC plan of reclamation is denied the applicant, the city will not issue a CDC. If approved by the city over the expressed unfavorable opinions of other local government{s), a written summary of the justifications for the city's action will be attached to the approval action. A copy of the Final Disposition of each CDC application will be provided to NCTCOG for the permanent records. II~PORTANT TOPICS NOT YET ADDRESSED This extensive document was prepared by the Staff Task Force in less than a gO day period, because of the deadline for submission of comments to the COE regarding the Final Regional EIS. It underwent seven drafts before emerging in this form. While it represents the best attempt at a regional consensus on a permit process, there are several important topics that have not yet been addressed. These are: a. Grandfathering of projects with existing permits. b. Sunsetting of permits for developments not started within a certain period. c. Exempting private development of a certain size (i.e., tract not exceeding a given size in a developed area.) d. Establishing a variance procedure for waiving compliance with one or more common permit criteria, recognizing that a project may be in the overall public interest (i.e., landfills, wastewater treatment plants, etc.) e. Setting common penalties for noncompliance. f. Banking of offsite valley storage within a particular routing reach with appropriate legal mechanisms to insure the preservation of those areas {i.e., park or open space dedication.) f. Setting time frames for processing CDC applications and the associated regional review and comment by local governments. Page 8 of 8 SS330ad ill4a3d 1101414133 Appendix C APPENDIX C MAILING ADDRESSES AND PHONE NUMBERS U.S. Army Corps of Engineers - Fort Worth District (817) 334-2185 FAX (817) 8857539 P.O. Box 17300 Fort Worth, Texas 765102-0800 Federal Emergency Management Agency - Region VI (817) 898-5104 FAX (817) 898-5165 Federal Center 800 North Loop 288 Denton, Texas 76201-3698 Texas Water Commission FAX (512) 463-8317 (512) 371-6304 P.O. Box 13087 Capital Station, Austin Texas 78711 North Central Texas Council of Governments Department of Environmental Resources (817) 64O-33OO FAX (817) 640-7ass P.o. Drawer COG Arlington, Texas 76005-5888 APPENDIX C LIST OF ACRONYMS Acronym Description CDC Corridor Development Certificate COE (USACE) U.S. Army Corps of Engineers CLOMR Conditional Letter of Map Revision FEMA Federal Emergency Management Agency GIS Geographic Information Systems; a geographic relational database HEC Hydrologic Engineering Center, Davis, Georgia HEC-1 Flood Hydrograph Computer Package HEC-2 Water Surfaces Profiles Computer Package NPDES National Pollution Discharge Elimination System NCTCOG North Central Texas Council of Governments PMF Probable Maximum Flood REIS (TREIS) (Trinity) River Environmental Impact Statement SPF Standard Project Flood TPDES Texas Pollution Discharge Elimination System TRIN Trinity River Information Network TWC Texas Water Commission USCS U.S. Department of Agriculture, Soil Conservation Service