TFMA Workshop Permitting Development in Special Flood Hazard Areas in the City of Houston

TFMA WorkshopPermitting Development in Special Flood Hazard Areasin the City of Houston October 2, 2007

Overview • Development Permit Process • Basic Permit Requirements • Floodplain Fill Mitigation Plans • Conveyance Zone Requirements • Floodway Requirements • Letters of Map Change (LOMCs) • Additional Resources • Questions/Answers

Project Location and the SFHA • Tools for determining location in the SFHA zone: • http:www.cohcdp.swmp.org/Website/ProView/viewer.htm • http://pwegis.pwe.ci.houston.tx.us/viewer1.htm • Call the Floodplain Management Office at 713-535-7666 • Projects involving critical facilities (defined in Sec. 19-2) are regulated within the 0.2% recurrence probability (500-year) floodplain (shaded Zone X) • If a project is in the SFHA or is a critical facility in shaded Zone X, contact the FMO to discuss requirements and potential impacts

Development Permit Process • NOTES • Commercial plans must be routed and are left with the cashiers at 3300 Main. • Applicants wishing to route their residential plans must leave them at One Stop.

Building Permits • What constitutes a “building”? • A structure that is walled and roofed – meaning two or more rigid exterior walls in place, and is adequately anchored to resist flotation, collapse, and lateral movement • Principally above ground and permanently affixed to a site • A lot with a house, garage, and shed is counted as one building • What type of work requires a City of Houston building permit? • New construction of buildings/structures • Alterations, repairs or additions to existing buildings/structures • Changes in the use or occupancy of an existing building/ structure • Interior tenant lease build-outs, remodeling and repairs • Exterior remodels, alterations or repairs • Moving/relocating existing buildings • Demolition (interior and complete buildings) • Fences over 8' high or fences constructed of concrete or masonry • Driveways and sidewalks (in city right-of-way) • Parking lot paving and repairs http://www.publicworks.houstontx.gov/planning/enforcement/permits.htm

Building Permit Applications • Must have assigned project number on application (cashier) • One Stop Plan Review or Commercial Plan Review for floodplain screening • Both residential and commercial building permit applications require a notarized signature – cashiers at 3300 Main are notaries • If project is a remodel in the floodplain that does not include an addition, and the cost of construction is not MORE than $10k residential/$15k commercial, then an FMO review and development permit are not required • For any questions regarding building permits, call 713-535-7500 to speak to someone in Code Enforcement

Basic Development Permit Application Requirements • For new construction, additions to existing buildings, and substantial improvements to existing buildings, the lowest floor and all utilities must be elevated or floodproofed (non-residential only) to at least 12 inches above the base flood elevation (BFE) • Loss of floodplain storage volume must be mitigated • Special requirements for projects located in the floodway and conveyance zone • A development permit will expire if development has not commenced within 18 months of issuance, and upon completion of the project for which it is granted, or after five years has elapsed from the date of permit issuance, whichever occurs first. (Ch. 19, Sec. 19-16 (b))

Basic Development Permit Application Requirements • Two sets of all plans, drawn to scale, must be signed and sealed by a professional engineer and/or architect, licensed to practice in the state of Texas • Vicinity map showing the site of the proposed development • Existing topography and the location, dimensions, and elevation of existing and proposed development • Elevations tied to a monument as identified on the Effective FIRM • Location of the property in relation to the SFHA; reference the FIRM panel by number • Elevation in relation to mean sea level for any proposed structures that are to be floodproofed • Planned elevation of the lowest floor in relation to mean sea level of all proposed structures • Development sites greater than 15,000 sq.ft. must include elevation contours set to a maximum increment of 1.0 foot Chapter 19, Sec. 19-17 (a)

Improvements to Existing Structures • Requirements for improvements to existing structures: • Establishment of market value of the structure • Appraisal from the Harris County Appraisal District (www.hcad.org) • Other appraisal performed by a Texas certified real estate appraiser, engineer, or architect • NFIP Final Proof of Loss statement for repair of flood damage • Computed actual cash value calculated by RSDE • Establishment of cost of construction for project • Cost estimate signed, sealed, and dated by a licensed engineer, architect or insurance adjuster • Owner-notarized cost estimate (when owner is performing the repairs) • Notarized contract agreement between the property owner and contractor • Cost estimate must include detailed line items establishing the nature of the proposed work • Relationship of market value to cost of construction: • In general, if the cost of improvement is LESS than 50% of the market value of the structure, it is considered a non-substantial improvement; otherwise, • If the cost of improvements is EQUAL to or GREATER than 50% of the market value, the structure must become compliant in order for a development permit to be issued

Improvements to Existing Structures • Effective 10/1/06, any combination of repairs for flood damage or additions to existing structures, occurring during any period of ten years for which the cumulative percentage of the cost of each addition or repair divided by the market value of the structure before the start of construction of each addition or repair equals or exceeds 50% • The City does not include water damage from non-storm related events (broken water main, etc.) in the cumulative cost of repairs

New Construction Requirements • Elevations of the following noted on plan and elevation view sheets (all required elevations must tie to a monument as identified on the Effective FIRM): • Existing ground elevation • Base flood elevation (BFE) from Effective FIRM data (except in Zone A) • Finished floor elevation (BFE plus 12 inches) • Elevation Certificate(s) (and plan sheets with elevations) must show Effective FIRM data and elevations, vertical datum and adjustment, and site benchmark used for vertical control • A floodproofing certificate (non-residential) if applicable, showing elevation in relation to mean sea level • An explanation of the potential impacts of the proposed development if adjacent to a watercourse or channel • All structures shall be designed with adequate drainage paths around structures on slopes to guide floodwaters around and away from those structures • Demonstration that development will not, at any time, diminish the storage volume of the SFHA; a mitigation plan will be required for any fill (e.g., fill dirt, concrete, etc.) that is brought into the SFHA • For Zone AO requirements, reference Ch. 19, Sec. 19-33 (b)

Floodproofing Certificate

Construction below BFE • Enclosed areas below the lowest floor of a building must be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters • This may be accomplished by: • A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding, with the bottom of all such openings no higher than one foot above grade; openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters, OR • A design certified by a registered architect or professional engineer licensed in the state of Texas Chapter 19 Guidelines, Sec. 19-32

Construction below BFE

Project Name I, do hereby certify that the opening(s) designed for installation in the aforementioned building will allow for the automatic equalizing of hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater during floods up to and including the base (100-year) flood. Signature Date Title Type of License License Number Address PROFESSIONAL SEAL Construction below BFE • If a drainage system is not certified, it must meet the following criteria: • Allow floodwaters to enter and exit the enclosed area by gravity flow; and • Have a number and size of openings sufficient to provide not greater than 0.1 foot of head loss • Calculations must be provided with the plan set demonstrating that the proposed drainage system will meet these requirements

Elevation Certificates • OMB No. 1660-0008 is the current version of the EC acceptable by the FMO as of January 1, 2007 • ECs are required for all three stages of a project: • Construction Drawings (when plans are submitted), • Building Under Construction (finished foundation), • Finished Construction (prior to occupancy) • All required information on a final EC must be filled out correctly – including photographs – or the FMO will not accept it

Latitude and Longitude • Provide latitude and longitude coordinates for the center of the front of the building; coordinates are mandatory on the third elevation certificate • Use decimal degrees (e.g., 39.5043º, -110.7585º) or degrees, minutes, seconds (e.g., 39º 30’ 15.5”, -110º 45’ 30.7”) • Latitude and longitude coordinates must be accurate within 66 feet • Provide the type of datum used to obtain the latitude and longitude (FEMA prefers the use of NAD 1983)

Photographs of Building • Photographs are required by the FMO on the final EC regardless of whether or not the EC is being used to obtain flood insurance “………………….. affix at least two building photographs below according to the instructions for Item A6. Identify all photographs with: date taken; “Front View” and “Rear View”; and, if required, “Right Side View” and “Left Side View.” If submitting more photographs than will fit on this page, use the Continuation Page….”

Basic Mitigation Rules • No fill may be placed until excavated material has been removed from the SFHA • Excavated volume that will be below the water surface of a permanent body of water is not mitigation • Excavation within the SFHA and below the BFE is the only acceptable method of mitigation of fill placed below the BFE in the SFHA, unless approved by the city engineer • Property owners cannot rely on the excavation from channel improvement projects as mitigation and cannot have the fill from a channel improvement project placed on their property unless they provide mitigation that is independent of the channel improvement project, except in the following cases: • FEMA has issued a CLOMR finding that the area of the SFHA to be filled will be removed from the SFHA by excavation related to the channel improvement project; and • The applicant has provided satisfactory documentation to the city engineer that work on the channel improvement project has progressed to a point where the proposed area of fill would not be inundated by the waters of the base flood Chapter 19, Sec. 19-17 (c)

Basic Mitigation Rules • The mitigation facility must be able to fill with water as the water surface in the SFHA rises and drain freely as the water in the SFHA subsides, unless the city engineer approves mechanical methods (e.g., pumps) to discharge water from the mitigation facility • The mitigation facility site must be located within 1/4 mile of the area where the applicant proposes to place fill and within the same watershed; the city engineer may consider exceptions to this policy on a case-by-case basis • The city engineer may approve subsurface mitigation facilities in situations where surface mitigation is not feasible; in such cases, the mitigation facility must be easily accessible for visual inspection • Prior to completion of the project, and/or occupancy of a structure, the applicant must provide as-built surveys and engineering calculations that demonstrate that there has been no net addition of fill in the SFHA Chapter 19, Sec. 19-17 (c)

Basic Mitigation Rules • A mitigation plan may create a surplus of volume which may be reserved and utilized for mitigating future on-site development that would result in fill being introduced below the BFE • When future development plans are submitted for permitting, the plan set must include the original mitigation plan drawings to substantiate that excess volume was created by that development • The “future” mitigation plan may utilize this excess volume according to the regulations in force at the time of application for the “future” permit • The use of surplus mitigation volume to compensate for the loss of floodplain storage volume due to future development at a separate site (off-site) is termed “mitigation banking”; a request for mitigation banking should be submitted to the FMO to be evaluated independently based on the merits of the proposal and the potential benefits for the floodplain • Mitigation credit may be created when an existing structure is demolished and fill materials are removed from the SFHA; credit is only granted for materials located between natural ground and the BFE • A location within the floodway may be used for mitigation of fill in the SFHA provided that the mitigation design meets all the requirements of Ch. 19, Secs. 19-17 and 19-43 Chapter 19, Sec. 19-17 (c)

Mitigation Plan Submittal Requirements • All mitigation plan drawings must be clearly identified as such and be separate from other site drawings • Drawings must be presented in plan and cross-section views to indicate existing conditions and proposed development • Include relevant bench marks and Effective FIRM elevation reference marks; datum conversion calculations must be presented • Tabulated, engineering calculations of cut and fill volumes (below BFE) associated with the cross-sections – may be developed using programs such as AutoCAD or Mircrostation (a contact phone number must be included and a CD containing the relevant software files must be submitted with the mitigation plan) • Plans for a mitigation facility must include a management plan consistent with the requirements of the Storm Water Quality Guidance Manual and the Select Minimum Design Criteria for Implementation of Best Management Practices for Storm Water Runoff Treatment, both 2001 editions, City of Houston • Any other pertinent information requested by the city engineer Chapter 19, Sec. 19-17 (c)

(50 (50 ’ ’ – – Top) Top) (40 (40 Base) Base) ’ ’ Fill Fill SLAB SLAB – – – – ’ ’ Top) Top) (46 (46 BFE BFE (56 (56 ’ ’ – – Base) Base) Volume of Fill = (Base Area + Top Area + Square Root (Base Area x Top Area)) x Height / 3 Volumeof Fill = (2,576 + 2,000 + 2,269.80) x 1 / 3 Volume of Fill = 2,282 cubic feet, or / 27 = 84.5 cubic yards Mitigation Plan View Drawings • Plan View Drawings must indicate: • Pre-development ground and structure elevations • Proposed ground and structure elevations • FIRM SFHA/floodway boundaries • FIRM cross-section location(s) and BFEs at the location of all proposed structures • Shaded, cross-hatched, etc., to differentiate between areas proposed to be cut and those proposed to be filled • Hydraulic connection between floodplain and the mitigation area(s), including the flowline elevations of all hydraulic connections Chapter 19, Sec. 19-17 (c)

Finished Floor Elevation (BFE + 12” minimum) ≥ 52.0’ SLAB Natural Ground = 50.0’ Fill (1’) BFE = 51.0’ Base = 56.0’ Mitigation Profile View Drawings • Profile drawings must indicate: • Representative cross-sections to define volumes of cut and fill areas • Existing and proposed ground and structure elevations • BFEs at each cross-section • Tabulated engineering calculations of cut and fill volumes (below BFE) associated with the cross-section profiles • A maintenance schedule for the mitigation facility • Other information requested by the city engineer Chapter 19, Sec. 19-17 (c)

Off-Site Mitigation Requirements • Plan must satisfy all of the requirements for on-site mitigation, in addition to the following: • City engineer must review and approve each application for an off-site mitigation facility • Certification from the mitigation site owner that states that the required mitigation volume will be available for this project and must indicate specific allowable volumes • Prior to introducing fill to the site, applicant must provide an engineering certification that demonstrates that all excavation for off-site mitigation has been completed

Off-Site Mitigation Requirements • The owner of the off-site mitigation facility shall execute a legal covenant restricting the use of the land occupied by the facility. Chapter 19 Guidelines, Exhibit B

Post-Development Mitigation Plan Submittal Requirements • Prior to completion of the project and/or occupancy of a structure, the holder of the development permit must provide as-built surveys and engineering calculations to demonstrate that there has been no net addition of fill in the SFHA • The owner of the mitigation facility must provide an annual certification of inspection signed by a registered professional engineer to confirm that the facility is functioning as approved in the development permit; for the purpose of this requirement, a mitigation facility is defined as a depressed area including an outfall drainage structure, similar in nature to a storm water detention facility • Where mitigation has been accomplished by site grading, and where no mitigation facility as defined above is present, the owner of the property will be required to certify annually on a city-provided form that the mitigation site is functioning properly, i.e., that no fill for landscaping or other purposes has been added to the mitigation area Chapter 19, Sec. 19-17 (c)

Preferred Design – New Development without Mitigation • The open area from ground level to the BFE shall be 30% or greater of the total area defined by the perimeter of the supported structure from ground level to the BFE • Requirement may be satisfied by latticework, or similar material, surrounding the perimeter of the supported structure from ground level to the BFE or higher • There must be no restriction to the flow of floodwaters beneath the supported structure • If the foundation of a new structure or addition to an existing structure is composed of pier and beam construction, and the cross-sectional area of the piers does not exceed 5% of the area of the footprint of the supported structure, then mitigation is not required for the volume of the piers • To the extent that cross-sectional area exceeds this 5% allowance, mitigation will be required for the volume calculated by the additional area multiplied by the height of the BFE above the average natural ground elevation beneath the supported structure

Conveyance Zones • The conveyance capacity of a site is the ability of the site to convey water during the occurrence of the base flood • The city engineer has defined areas that have conveyance capacity to include areas inside the SFHA which also meet one or more of the following conditions: • The area is inside the regulatory floodway; • The area is within a 100-foot buffer zone around the regulatory floodway; • The area is between channel centerlines in or near areas designated as AO zones on the FIRM (overflow areas between two channels); or • Depths (defined as BFE minus natural ground elevation) in the area are greater than 18 inches and the area is hydraulically connected to the floodway by areas that also have depths greater than 18 inches • Conveyance zone maps can be accessed at the following links: • www.cohcdp.swmp.org/Website/ProView/viewer.htm • www.gims.houstontx.gov/viewer1.htm • Improvements must meet floodplain requirements plus demonstrate that existing conveyance capacity will not be impacted

Conveyance Zones • The city engineer is currently considering revisions to the conveyance zone policy; however, until such revisions are approved by the director of Public Works & Engineering, development permit applicants for projects located in the conveyance zone should contact FMO staff to discuss the nature and degree of analysis that may be required for a specific site

Conveyance Zones The level of analysis and documentation that must be provided to obtain a development permit will vary with the size and complexity of the proposed development. The analysis may include some or all of the following components: • Develop a site plan that includes existing topography and structures with conveyance flow paths and directions indicated across the site; conveyance flow paths may not necessarily align with the centerline of the modeled stream – show areas of ineffective flow on the site plan, extending off-site as necessary • On the existing conditions site plans, identify points of flow constriction for each flow path • Establish cross-sections at constriction points • For each cross-section, determine appropriate roughness (“n”) values, based on site-specific conditions; choose the appropriate “n” value (see Ch. 19 Guidelines, Sec. 19 – 17 (d))and document roughness selection with aerial and/or site photographs • For each cross-section, calculate the conveyance (K) for existing conditions; where K = 1.49AR2/3/n, and the depth of the cross-section is established from the BFE

Conveyance Zones • Develop a site plan that includes proposed topography, structures, conveyance flow paths and directions in a manner similar to that employed for existing conditions; show areas of ineffective flow on the proposed site plan, extending off-site as necessary • Identify proposed points of flow constriction and construct cross-sections for the proposed conditions; identify site-specific proposed roughness values along the proposed cross-sections and document how these roughness values were determined; calculate the conveyance for the proposed conditions • Cross-sections should be limited to the site boundaries so that the calculations compare existing and proposed conveyance across the site (representative of the flow in that portion of the site) • Compare the proposed conveyance capacity with the existing conveyance capacity • Include conveyance calculations in the documentation • Based on the results of the conveyance analysis and the location of the site, a No-Adverse Impact Analysis may also be required Chapter 19, Sec. 19-17 (d)

Development Permit Fees • Fees for development permits to cover costs of reviews Chapter 19 Guidelines, Sec. 19-17 (e)

Projects Located in the Floodway • No permit will be issued for development in the floodway if: • The project involves an encroachment due to fill • The project involves new construction, additions to existing structures, or substantial improvements to any structures • No floodway has been designated (Zone A) • Issuance of a development permit requires floodway to be delineated unless project is a single-family residence to be constructed on a tract not to exceed 15,000 square feet in area Chapter 19 Guidelines, Sec. 19-43

Projects Located in the Floodway • A permit may be issued for projects for facilities necessary to protect the health, safety, and welfare of the general public or construction of a new bridge or the repair or replacement of an existing bridge if: • The cumulative effect of the proposed development when combined with the existing development will not have an adverse effect on flood levels at any point within the city during occurrence of the base flood • The construction will not impede the flow of floodwaters • The construction will not result in an adverse effect on the conveyance capacity during the occurrence of the base flood • The lowest horizontal structural member, including bridges, must be 18 inches above the BFE; the city engineer may grant a deviation from this standard if the city engineer determines that construction is not practical based upon sound engineering principles Chapter 19 Guidelines, Sec. 19-43

Variance Procedures • A variance may be sought only on the basis that the imposition of the Chapter 19 requirements for the issuance of a permit to the applicant constitutes an exceptional hardship • A variance can only be filed after a development permit application has been rejected and before a development permit has been issued • Applicant must be the property owner or the attorney-in-fact for the owner • Applicant fills out an “Application for Variance” form (available at the FMO) • Application for Variance is submitted to the FMO, along with application fee of $200 by certified check made out to the City of Houston • City engineer will review the Variance Request and will transmit the request (and fee), along with recommendations to the General Appeals Board • General Appeals Board usually meets on the 4th Thursday of every month and the Board must receive the Variance Request from the city engineer a minimum of ten (10) business days prior to a scheduled meeting Chapter 19, Sec. 19-20 through Sec. 19-22

Letters of Map Change (LOMCs) • Letter of Map Amendment (LOMA) • When issued by FEMA, removes a structure or lot from the SFHA • Letter of Map Revision (LOMR) • FEMA’s modification to an Effective FIRM based on physical changes to a channel, development of flood control structures, improved methodology and/or data, or a revision of floodway boundaries • Letter of Map Revision – Based on Fill (LOMR-F) • FEMA’s modification of the SFHA shown on the FIRM based on the placement of fill outside of the existing regulatory floodway

Letters of Map Change (LOMCs) • MT-EZ • Used to request that FEMA remove a single structure or parcel of land from the SFHA; FEMA approval of the application results in a LOMA • Does not require approval of the city engineer • Application form can be accessed at http://www.fema.gov/library/viewRecord.do?id=2328 • MT-1 • Conditional and Final Letters of Map Amendment and Conditional and Final Letters of Map Revision based on Fill • Used for multiple structures or parcels of land • Requires approval of city engineer • Application form can be accessed athttp://www.fema.gov/library/viewRecord.do?id=1492 • MT-2 • Conditional and Final Letters of Map Revision • Used for multiple structures or parcels of land • Requires approval of city engineer • Application form can be accessed at http://www.fema.gov/library/viewRecord.do?id=1493

Letters of Map Change (LOMCs) • Applicant completes MT-EZ, MT-1, or MT-2 form • Applicant sends three (3) completed forms, processing fee, report, correspondence, and all supporting documentation to the FMO • FMO staff reviews submittal and forwards it to city engineer for signature (except for MT-EZ) • FMO forwards package to FEMA, retains one copy for FMO files, and returns one file to Applicant

Coordination with HCFCD • MT-2 applications require coordination and signature approval from HCFCD prior to submittal of the application to the FMO • Projects that may impact a watercourse or drainage channel, particularly those within HCFCD right-of-way, must be coordinated and approved by HCFCD prior to being approved for a development permit • No-Adverse Impact studies must include a letter of concurrence from HCFCD

Final Considerations • The work priorities of FMO staff are the following, inorder: • Anything the city engineer wants done • Scheduled appointments • Plans on route for review • Walk-in customers • Potential development permit applicants are ENCOURAGED to contact the FMO to schedule an appointment prior to initiating project design in order to discuss the requirements of Chapter 19

City of Houston Floodplain Management Office http://www.publicworks.houstontx.gov/planning/cityengineer/floodplain.htm Chapter 19 Ordinance http://www.publicworks.houstontx.gov/planning/cityengineer/docs/chapter_19_flood_plain.pdf http://www.swmp.org/downloads/Chapter%2019%20CURRENT%202006.pdf Chapter 19 Guidelines http://www.publicworks.houstontx.gov/planning/cityengineer/floodplain.htm http://www.swmp.org/downloads/Chapter19.pdf GIMS http://www.gims.houstontx.gov/ Historical FIRM Panels http://www.swmp.org/mappdf/ Storm Water Management Program http://www.swmp.org FEMA Elevation Certificate http://www.fema.gov/business/nfip/elvinst.shtm Online Building Permits http://pdinet.pd.ci.houston.tx.us/permits/index.asp Additional Resources

Contact Information City of Houston Floodplain Management Office 3300 Main Houston, TX 77002 713-535-7666 John J. Sakolosky, PE City Engineer/Floodplain Administrator City of Houston 611 Walker, 19th Floor Houston, TX 77002 713-837-7114 john.sakolosky@cityofhouston.net Mark L. Loethen, PE Assistant Director, Office of the City Engineer City of Houston 611 Walker, 19th Floor Houston, TX 77002 713-837-0724 mark.loethen@cityofhouston.net

Questions/Answers John A. Laser, PE, CFM Senior Project Manager TCB 5757 Woodway, Suite 101W Houston, TX 77057 713-267-2979 john.laser@tcb.aecom.com

TFMA Workshop Permitting Development in Special Flood Hazard Areas in the City of Houston