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DR9305-CS 930716 (2)The City With A Beautiful P.O. Box 478 Coppell, Texas 75019 214-462-0022 July 16, 1993 Mr. Michael Baker Jr., Inc. 3601 Eisenhower Avenue Suite 600 Alexandria, Virginia 22304 Attention: Mr. David P. Preusch, P.E. RE: Case Number 93-06-267R, Request for a conditional Letter of Map Revision on Grapevine Springs Park in Coppell, Texas Grapevine Springs Park Project Dear Mr. Preusch: Enclosed please find revised FEMA Forms 1, 2, 4 & 5. The technical report (dated 6-3-93) prepared by Graham Associates, Inc., which contains HEC-2 hydraulic models, floodway and floodplain mapping and construction plans for the proposed project, is unaffected by the revised forms. Please be advised that the City of Coppell is processing a check in the amount of $735.00 to the Washington office of FEMA. Because this is a City project, it's my opinion that a review fee is not warranted. However, in an effort to expedite the review, the City is paying the fee, at this time. The City will be requesting that FEMA review this and refund the fee if they determine that it was not warranted. As the Floodplain Administrator for the City of Coppell, I request that FEMA review the technical report and issue a CLOMR. Also, I request that FEMA revise the floodways, in accordance with this report, after the project is constructed. The City of Coppell agrees to maintain and make necessary repairs to the hydraulic improvements proposed by this project, as described in the attached maintenance plan. If you have any technical questions about the project please contact Neal Chisholm of Graham Associates (817-640-8535). However, any administrative questions should be directed to myself at 214-393-1016. Thank you for your consideration of this request. Sincerely, Engi~ CC: Jack Quarles, FEMA Region VI Jack Hedge, P.E., Dallas County Neal Chisholm, P.E., Graham Assoc. Steve Goram, Director of Public Works file/kgriffin/gpvsps.prk The City With A Beautiful Future P.O. Box 478 Coppell, Texas 75019 214-462-0022 July 16, 1993 Maintenance Plan Grapevine Springs Park Project City of Coppell, Texas The purpose of the following maintenance plan is to provide adequate hydraulic conveyance in the park project area, especially the by-pass channel. Additional and/or frequent maintenance may be necessary for park access, aesthetics and/or park usability. The park shall be visually inspected at least once a year by City staff personnel familiar with the hydraulic considerations. Also, the park shall be visually inspected after significant flood events. Written notes, photographs and/or notations on maps or drawings will be taken by the inspector and retained by the City. The grass, weeds and/or brush in the main channel and in the by-pass channel will be mowed at least twice a year. Accumulated sediment will be removed from the main and by-pass channels and disposed of in non-floodway areas. Sediment removal will be on an as-needed basis. Minor amounts of water borne debris will be removed twice a year in conjunction with park mowing. Fallen trees, logs and other large debris that is obstructing the main or by-pass channels, (or that may become lodged in the stream channel during a flood event) shall be removed promptly. Future repairs to the proposed foot bridges, the proposed concrete erosion protection and the existing stone lake walls shall be performed in a manner consistent with FEMA rules regarding work in a designated floodway. file/kgriffin/gpvspspk.prk FEMA U~ ONLY REVISION REQUESTOR AND COMMUNITY OFFICIAL FORM REV. FORM 7/15/93 EX: The basis for tiffs revision request is (are): (check all that apply) ~ Physical ~g~ gxis g [] Proposed ["] Improved methodology ~-[ Xmproved data ~-] Floodway rovision [-] Other Explain 2. Flooding Source: Grapevine Creek 3. ProjectNameAdentifier: Grapevine Springs Park 4. FEMA zone designations affected: AE (ex~mplw. A, Al/iA/); A1-A3{~,,A99;.AE, V, VI-V30, VE;'B, C, D, X) 5. The NFIP map panel(s)affected for all impa~ eommtmities i~ (are): Community Community Map Panel Effective No. Name County Stat~ No. No. Date 480301 Katy, City Harris, Fort Bend TX 480301 000SD 02/08/83 480287 Harris County Harris TX 48201C 0220G 09/28/90 480170 Coppell Dallas & Denton TX 480170 0010D 10/16/91 The submitted request encompasses the following types of flooding, structures, and associated disciplines: (check all that apply) Types of Flooding Structures Disciplines* [] Riverine [] Channelization [] Water Resources [] Coastal ~] Levee/Floodwall [-'] Hydrology [--] Alluvial Fan [-'] Bridge/Culvert [~] Hydraulics ~-] Shallow Flooding [] Dam [-=] Sediment Transport [] Lakes J-'] Coastal [--] Interior Drainage Affected by [~] Fill [] Structural wind/wave action [] Pump Station '['-] Geoteehnica[ [] Yes [] None [--'] Land Surveying ['-] No ~] Other (describe) [] Other (describe) [] Other (describe) * Attach completed "Certification by Regisl~-ed Professional and/or Land Surveyor" Form for each discipline checked. (Form 2) October 1992 Page l of 5 e If yes, give reason: REVISION REQUESTOR AND COMMUNITY OFFICIAL FORM Floodway Information REV. 7/15/93 Does the affected flooding source have a floodway designated on the effective FIRM or FBFM? [~] Yes [-'] No Does the revised floodway delineation differ from that shown on the effective FIRM or FBFM? [] Yes [--INo BETTER CROSS SECTION AND TOPOGRAPHIC DATA Attach request to revise the floodway from community CEO or designated official. ATTACHED Attach copy of either a public notice distributed by the Community stating the community's intent to revise the floodway or a statement by the community that it has notified all affected property owners and affected adjacentjurisdictions. ALL AFFECTED PROPERTY OWNERS NOTIFIED. Does the State have jurisdiction over the_~.floodway or it's ad.option by communities particioating in theNFIP? [--]Yes I~lNo not when tne community partzclpares in the FEMA program. If yes, attach a copy of a letter notifying the appropriate State agency of the floodway revision and documentation of the approval of the revised floodway by the appropriate State agency. With floodways: lA. Proposed Encroachments Does the revision request involve fill, new construction, substantial improvement, or other development in the floodway? [lq Yes [ | No 1 It. If yes, does the development cause the 100-year water surface elevation increase at any location by more than 0.000 feet? [] Yes ~] No Without floodways: 2A. Does the revision request involve fill, new construction, substantial improvement, or other development in the 100-year floodplain? [~] Yes [--] No 2B. If yes, does the cumulative effect of all development that has occured since the effective SFHA was originaly identified cause the 100-year water surface elevation increase at any location by more than one foot (or other surcharge limit if community or state has adopted more stringent criteria)? [~ Yes [~ No If answer to either Items lB or 2B is yes, please provide documentation that all requirements of Section 65.12 of the NFIP regulations have been met. SEE REPORT NARRATIVE Revision Requestor Acknowledgement · Having read NFIP Regulations. 44 CFR Ch. I, parts 59, 60, 61, 65, and 72, I believe that the' ' ' proposed revision [] is ['"] is not in compliance with the requirements of the aforementioned NFIP Regulations. Community Official Acknowledgement Was this revision request reviewed by the community for compliance with the community's adopted floodplain management ordinances? ~-~ Yes [~] No Does this revision request have the endorsement of the community? ~'] Yes [--] No If no to either of the above questions, please explain: Please note that community acknowledgement and/or notification is required for all requests as outlined in Section 65.4 (b) of the NFIP Regulations. October 1992 Page2of5 e RI~VI~ION REqUESTOR AND COMMUNITY OFFICIAL FORM Operation and Maintenance Does the physical change involve a flood control structure (e.g., levees, floodwalis, channelization, basins, dams)? ~ Yes [] No IMPROVEMENTS IN THE BY-PASS CHANNEL If yes, please provide the following information for each of the new flood control structures: Inspection of the flood control project will be conducted periodically by CITY OF lentity~ COP P ELL with a maximum interval of 12 months between inspections. Based on the results of scheduled periodic inspections, appropriate maintenance oftbe flood control facilities will be conducted by CITY OF COPPELL (entity) to ensure the integrity and degree offlood protection of the structure. C. A formal plan of operation, including documentation of the flood warnLng system, specific actions and assignments of responsibility by individual name or title, and provisions for testing the plan at intervals not less than one year, [~ has ~] has not been prepared for the flood control structure. PROJECT CONSISTS OF SIMPLE CHANNELS. NOTHING TO OPERATE OR TEST. D. The community is willing to assume responsibility for ~ performing [] overseeing compliance with the maintenance and operation plans of the GRAPEVINE SPRINGS PAP, t( flood control structure. If not performed promptly by an owner other than the communLty, the community will provide the necessary services without cost to the Federal government. Attach operation and maintenance plans Requested Response from FEMA After examining the pertinent NFIP regulations and reviewing the document entitled #Appeals, Revisions, and Amendments to Flood Insurance Maps: A Guide for Community Officials,n dated January 1990, this request is for a: X a. CLOMR b. LOMR c. PMR A letter from FEMA commenting on whether a proposed project, ffbuilt as proposed, would justify a map revision (LOMR or PMR), or proposed hydrology changes (see 44 CFR Ch. I, Parts 60, 65, and 72}. A letter from FEMA officially revising the current NFIP map to show changes to floodplains, floodways, or flood elevations. LOMRs typically depict decreased flood hazards. (See 44 CFR Ch. l, Parts 60 and 65.} A reprinted NFIP map incorporating changes to floodplains, floodways, or flood elevations. Because of the time and cost involved to change, reprint, and redistribute an NFIP map, a PMR is usually processed when a revision reflects increased flood hazards or large-scope changes. (See 44 CFR Ch. I, Parts 60 and 650 d. Other: Describe October 1992 Page Forms Included Form 2 entitled "Certification By Registered Professional Engineer And/Or Land Surveyor" must be submitted. The following forms should be included with this request if (check the included forms): Hydrologic analysis for riverine flooding differs from that used to develop FIRM Hydraulic analysis for riverine flooding differs from that used to develop FIRM The request is based solely on updated topographic information [-'] Hydrologic Analysis Form (Form 3} Riverine Hydraulic Analysis (Form 4) Riverine Mapping (Form 5) · The request involves any type of channel modification · The request involves new bridge or culvert or revised analysis of an existing bridge or culvert [-=] Channelization (Form [] Bridge/Culvert Form (Form 7} Initial Review Fee · The minimum initial review fee for the appropriate request category has been included. Yes I-'I If yes, the amount submitted is $ 7 3 5.0 0 or This request is for a project that is for public benefit and is intended to reduce the flood hazard to existing development in identi~ed flood hazard areas as opposed to planned floodplain development. I--'l'/'es 1--'! No October 1992 Pa~t4 of 5 Note: I understand that my signature indicates that all information submitted in support of this request is correct. Si~atu~e of Revision Requesmr Note: Signature indicates that the community understands, from the revision requestor, the impacts of the revision on flooding conditions in the community. Allen Bud Beene~ P.E. Director Printed Name and Title of Revision Requestor Kenneth M. Griffin, P.E. City EnRineer Printed Name and Title of Community Official Dallas County Company Name City of Coppell Community Name Date July 15, 1993 Date July. 15. 1993 Attach letters from all affected jurisdictions acknowledging revision request and approving changes to floodway,/fapplicable. Note: Although a photograph of physical changes is not required, it may be helpful for FEMA's review. October 1992 Pa~eSof5 · ~s:' P U CAT~ONaL-'~"IFIcA'r'/o~I' ~ ~ CONI~TIONAL L~ ~ r~s OF MAP ~EVI~t~. ~ OF MAP ~'V~I0~q AND PlqY~CAL ~tP ~,r~._.~q FEMA L'SE ONLY CERTIFICATION BY REGISTERED PROFESSIONAL ENGINEER AND/OR LAND SURVEYOR FORM 2 This certification is in accordance with 44 CFR Ch. I, Section 65.2. [ am licensed with an expertise in water resources - hydraulics and hydrology [example: water resources (hydrology, hydraulics, sediment transport, in,er(or drainage)* structural, geotechnical, land surveying.] I have 16 years experience in the expertise listed above. [ have [] prepared [] reviewed the attached supporting data and analyses related to my expertise. I [] have [] have not visited and physically viewed the project./s £ te [n my opinion, the following analyses and/or design, were performed in accordance with sound engineering prac~ces: Grapevine Springs Park Hydraulic Study Based upon the following review, the modifications in place have been constructed in general accordance with plans and specifications. Basis for above statement: (check all that apply) a. [] Viewed all phases of actual construction, n/a b. [] Compared plans and specifications with as-built survey information, n/a c. [] Examined plans and specifications and compared with completed projects, n/a d. [] Other Project has not been built as of 6-1-93. All information submitted in support of this request is correct to the best of my knowledge. [ understand that any false statement may be punishable by fine or imprisonment under Title 18 of the United States Code, Section 1001. Name: Neal A. Chisholm Title: Senior Eng ineer (please print or type) Registration No. 50641 State Texas Type of License Profess.ional Engine~er JULY 15~ 1993 Date *Specify Subdiscipline (please print or typeJ Expiration Date: Note: I nser~ not applicable (N/A} when s~a~ement does not apply. October 1992 12-31-93 Pa~e I of I FEMA USE ONLY RIVERINE HYDRAULIC ANALYSIS FORM Community Name: Coppell, Texas REV. FORM 4 7/15/93 Flooding Source: Grmnpv~np Crm~k Project Name/ldenti~er: Grapevine Springs Park Reach to be Revised Downstream limit Bethel Rd. (Sect. 27620) Upstreamlimit IH-635 (Sect. 38235) Effective FIS I I Not studied [] Studied by approximate methods Downstream limit of study Upstream limit of study Studied by detailed methods Downstream limit of study Upstream limit ofstudy eornorat~_ 1 Floodway delineated [] Downstream limitoffloodway confluence Elm Upstream limit offloodway confluence Elm Fork Trinity River Fork Trinity River Hydraulic Analysis Why is the hydraulic analysis different from that used to develop the FIRM. (Check all that apply) f-'} Not studied in FIS [] Improved hydrologicdata/analysis. Explain: Improved hydraulicanalysis. Explain: B~ttmr Tono~ranhic data. more cross sections - - [] Flood control structure. Explain: [--I Other. Explain: October 1992 Page 1 of 5 APPLICATION;CERI~FICATION FORMS FOR CONDrr~OHAL r/.~fz.~ OF MAi= REVISION. LETTER OF MAP REVI~ON AND PNYSICA~ MAP Modets Submitted Full input and output listings along with files on diskette {if available) for each of the models listed below and a summary of the source of input parameters used in the models must be provided. The summary must include a complete description of any changes made from model to model (e.g. duplicate effective model to corrected effective model). Only the Duplicate Effective and the Revised or Post-Project Conditions models must be submitted. See instructions for directions on when other models may be required. Only the 100-year flood profile is required for SFHAs with a Zone A designation. [] Duplicate Effective Mode[ Copies of the hydraulic analysis used in the effective FIS, referred to as the effective models Il0-, 50-, 100-, and 500-year multi-profile runs and the floodway run) must be obtained and then reproduced on the requestor's equipment to produce the duplicate effective model. This is required to assure that the effective model input data has been transferred correctly to the requestor's equipment and to assure that the revised data will be integrated into the effective data to provide a continuous FIS model upstream and downstream of the revised reach. [] Corrected Effective Model The corrected effective model is the model that corrects any errors that occur in the duplicate effective model, adds any additional cross sections to the duplicate effective model, or incorporates more detailed topographic information than that used in the currently effective model. The corrected effective model must not, reflect any man-made physical changes since the date of the effective model. An error could be a technical error in the modeling procedures, or any construction in the floodplain that occurred prior to the date of the effective model but was not incorporated into the effective model. ~ Existing or Pre-Project Conditions Model The duplicate effective or corrected effective model is modified to produce the existing or pre-proiect conditions model to reflect any modifications that have occurred within the floodplain since the date of the effective model but prior to the construction of the project ['or which the revision is being requested. If no modification has occurred since the date of the effective model, then this model would be identical to the corrected effective or duplicate effective model. ~ Revised or Post-Project Conditions Model The existing or pre-proiect conditions model (or duplicate effective or corrected effective model, as appropriate) is revised to reflect revised or post-project conditions. This model must incorporate any physical changes to the floodplain since the effective model was produced as well as the effects of the project. Natural Floodway Natural Floodway Natural Floodway Natural Floodway Other: Please attach a sheet describing all other models Natural Floodway submitted. PROPOS ED [-X'] [] October 1992 Page 2 of 5 · .ppLICATION/CERTIIrICATION FORMS FOR CONDrrIONAL LETTER OF MAP REVISION. LETTER OF BL~,P REV1SION A~ID PHY~XCAL ~ REVISION ~1 v ~,til.'$ r_, ri ~ Dlq. AL LIC A.NALYblb Model Parameters (from model used to revise lO0-vear water surface etevations~ Discharges: Upstream Limit Downstream Limit lO-year 7~300 6,700 50-year lO,O00 9.400 lO0-year 11.200 10.500 500-year .14,2QO 13,400 Attach diagram showingchangesinl00-yeardischarge changes between 35570 & 35770 Explain how the starting water surface elevations were determined 100 & 500 year frgm Kimley-Horn 1-2-89. 10 & 50 year printed profile Starting Wa~rSur~ce Elevation lO-year 489.65 at section 50-year 491.70 27070 100-year 492.43 _Floodway 492.82 500-year 494.05 Give range of friction loss coefficients for effective FIS channel .015 to .045 overbank .050 to .070 If friction loss coefficients are different anywhere along the revised reach from those used to develop the FIRM, give location, value used in the effective FIS, and revised values and an explanation as to how the revised values were determined. Location FIS Revised 27620 to 30130 chan.= .045 .030 to .060 27620 to 30130 overbank .065 to .070 .040 to .120 Explain: LoWer chan. 'n' due to existing improvements. Higher chan. 'n' due tO. t,rees in channe,1. Lower overbank 'n' due Eigher overbank 'n' due to dense trees and brush _ to mowed grass. 4 Describe how the cross section geometry data were determined (e.g., field survey, topographic map, taken from previous.study) and list cross sections that were added. The new sections (i.0 thru 6.0) are from field surveys or field surveyed models. October 1992 topo maps. The other sections from the effective FIS Page 3 of 5 A_Pp LICATION~C£BTIFICATION FOR~ FOR CONDITIONAL LETTER OF ~ RElflSION. LETTL~ OF ~ R~VISION AI~D pHYSICAL ~ R~%'L~ION Mode[ Parameters ~Cont'd) Explain how reach lengths for channel and overbanks were determined: Reach lengths scaled from topo map and plots of field surveyed data. 3. 4. 5. Results (from model used to revise 100-year water surface elevations) Do the results indicate: a. Water surface elevations higher than end points o~cross seeti°ns?f~q Yes [--] No b. Supercritical depth? c. Critical depth? d. Other unique situations? If yes to any of the above, attach an explanation that discusses the situation and how it is presented on the profiles, tables, and maps. What is the maximum head loss between cross-sections? at existing drop structure What is the distance between the cross-sections in 2 above? What is the maximum distance between cross-sections? Floodway determination a. What is the maximum surcharge allowed by the community or State? b. What is the maximum surcharge for the revised conditions? c. What is the maximum velocity? at 38235 d. What type of erosion protection is provided7 qonc. slooe Explain: Purpose of the oroiect is in thm by pass channel. Max. vel. vel. in the bv mass channel is 6.86 frs [] Yes -[-~] No [] Yes [] No [] Yes [] No 4.89' 3' 1305' 1.0 foot 0,59 foot 15.3 , fps pavement to remair and mrevent erosion is NOT on vroiect site. Max. October 1992 Page 4 of 5 .~p, ,c^~o.,czm~mc^~zoN roams ma CoNDmo~. Lcrr£a or M~ ~XV~0.. ,-~rrmm or ~J. zzvmo. ~u ~..vszc~. ~ ~-~mo~ ]~IVERINE HYDRAULIC ANALYSIS FORM REV. Results (Cont'd) Is the ~izcharge value used to determine the floodway anywhere different from that used to determine the natural 100-year flood elevaUons? If yes, explain: 6-16-93 Yes [] No Attach a Floodway Data Table showing data for each~ross section listed in the published floodway data table in the FIS report. Do 100-year water surface elevations increase at any location? Attached [] Yes [] No If yes, please attach a list of the locations where the increa~s occur, state whether or not the increaae~ are located on the requestor's property, and provide an explanation of the reason for the increases. Water surface increases between the RR and IH-63~ are due to a more accurate existing cond. hydraulic model. Water surface increase in the Park area are only 0.01 feet and are contained on the requestor's property. The energy gradeline decrease 0.03 feet in this area. Please attach a completed comparison table entitled: Water Surface Elevation Check. Attached Revised F[RM/FBFM and Flood Profiles The revised water su~ace elevations tie into those computed by the effective FIS Model (10-, $0% 100-, and 500-year). downstream of the project at cross-section 27400 within 0.00 feet and upstream of the project at cross section 38235 within O. O0 feet. The revised floodway elevations tie into those computed by the effective FIS model, down. stream of the project at cross section 27400 within 0.00 feet and upstream of the project at cross secuon 38235 within 0.00 feet. Attach profiles, at the same vertical and horizontal scale as the profiles in the effective FIS report, showing stream bed and profiles of all floods studied (without encroachment). Also, label all cross sections, road crossings (including low chord and top-of-road data), culverts. tributaries, corporate limits, and study limits. .%ttached Proceed to Riverine Mapping Form. October 1992 Community Name: Flooding Source: FEMA USE ONLY RIVERINE MAPPING FORM CITY OF COPPELL? TEXAS GRAPEVINE CREEK REV. FORM 5 7/15/93 Project Name/Identifier: GRAPEVINE SPRINGS PARK Mapping Changes A topographic work map of suitable scale, contourinterval, and planimetric definition must be submitted showing (insert N/A when not applicable): A. Revised 100- year floodplain boundaries (Zone A) B. Revised 100- and 500-year floodplain boundaries C. Revised 100-year floodway boundaries D. Location and alignment of all cross sections used in the revised hydraulic model with stationing control indicated E. Stream alignments, road and dam alignments F. Current community boundaries G. Effective 100- and $00-year floodplain and 100-year floodway boundaries from the FIRM/FBFM reduced or enlarged to the scale of the topographic work map H. Tie-ins between the effective and revised 100- and 500-year floodplains and 100-year floodway boundaries I. The requestor's property boundaries and community easements J. The signed certification of a registered professional engineer K. Location and description of reference marks L. Vertical datum lexample: NGVD 1929, NAVD 1988, etc.) [fanyoftheitemsaboveare marked noor N/A, pleaseexplain: A. No to Zone 'A' floodplains H. Tie-in w/ LOMA 8/10/92 for field surveys, City topo maps used for base maps. Included [~ Yes [~] No ~=1 N/A [] Yes i--] No [] N/A [] Yes [~] No [] N/A [] Yes [] No [] N/A [] Yes [~] No [] N/A [] Yes f--I No [] N/A [X"! Yes [] No [] N/A [] Yes [-'] No [] N/A [-%'] Yes [] No [] N/A [] Yes [-'] No [] N/A [] Yes [22] No [] N/A ['X'] Yes [=-] No [[[] N/A mrooosed changes L. FEMA RMs used What is the source and date of the updated topographic information (example: orthophoto maps, July 1985; field survey. May 1979, beachorofiles June 1987 .t,. ~ City aerial topo maps dated 2-29-92 and on-site field ~urveys $'-8~"And ~-~2 What is the scale and contour interval of the following workmaps? a. Effective FIS UNK~qQWN scale UNKNOWN Contour interval b. Revision Request 1"=200' scale 2' Contour interval Attach an annotated FIRM and FBFM at the scale of the effective FIRM and FBFM showing i the revised 100-year and 500-year floodplains and the 100-year floodway boundaries and how they tie into those shown on the effective FIRM and FBFM downstream and upstream of the revision. SEE ATTACHED Attach additional pages if needed. October 1992 Page I of 3 Mapping Changes (Continued) Flood Boundaries and 100-year wa~er surface elevations: Has the 100-year floedplah~ been shifted or increased or the 100-year wa~er surface elevation increased at any location on property other than the requestor's or community's? f=-[ Yes [] No [f yes, please give the location of shift or increase and an explanation for the increase. PROPOSED INCREASED FLOOD ELEVATIONS ABOVE THE REVISED EXISTING FLOOD ELEVATIONS ARE ON THE REqUESTORS PROPERTY bo Have the affected property owners been notified of this shift or increase and the effect it will have on their property? [-'] Yes [] No If yes, please attach letters from these proper~y owners stating they have no objections to the revised flood boundaries. What is the number of insurable structures that will be impacted by this shift or increase? ZERO Have the floodway boundaries shifted or increased at any location compared to those shown on the effective FBFM or FIRM? ~-] Yes [] No If yes, explain: EFFECTIVE FIS CHANNEL WHICH IGNORED THE EXISTING, NATURALLY CREATED BY-PASS CARRIES A LARGE PART OF THE DISCHARGE BUT WAS EXCLUDED FROM THE FLOODWAY IN THE EFFECTIVE FIRM Manual or digital map submission: [] Manual [] Digital Digital map submissions may be used to update digital FIRMs (DFIRMs). For updating DFIRMs, these submissions must be coordinated with FEMA Headquarters as far in advance of submission as possible. October 1992 Pa~e 2 of 3 Earth Fill Placement Has fill been placed in the regulatory floodway? If yes, please attach completed Riverine Hydraulic Form. Has fill been placed in floodway fringe (area between the floodway and 100-year floodplain boundaries)? If yes, then complete A, B, C, and D below. A. Are fill slopes for granular materials steeper than one vertical on one-and-one-haft horizontal? If yes, justify steeper slopes [] Yes [] No [--1 Yes [] No Yes [] No Is adequate erosion protection provided for fill slopes exposed to moving flood waters? (Slopes exposed to flows with velocities of up to 5 feet per second (fps) during the 100- year flood must, at a minimum, be protected by a cover of grass, vines, weeds, or similar vegetation; slopes exposed to flows with velocities greater than 5 fps during the 100-year flood must, at a minimum, be protected by stone or rock riprap.) [~ Yes [] No If no, describe erosion protection provided see cons ~_r.uction_. p. lans Has all fill placed in revised 100-year floodplain been compacted to 95 percent of the maximum density obtainaSle with the Standard Proctor Test Method or acceptable equivalent method? fill settlement OK in this area of the park [] Yes ~J~ No Can structures conceivably be constructed on the fill at any time in the future? fill is not out of 100 year floodplain [] Yes [] No If yes, provide certification of fill compaction (item C. above} by the community's NFIP permit official, a registered professional engineer, or an accredited soils engineer. OctoU~r 1992 Pag~ 3 ~f3 DALLAS COUNTY PUBLIC WORKS July 15, 1993 Mr. Ken Griffin City of Coppell 255 Parkway Blvd. Coppell, Texas 75019 Re; Proposed Grapevine Springs Park - FEMA Submittal Dear Mr. Griffin; We are aware that the Grapevine springs Park Project currently being proposed by the Dallas County Public Works will raise the 100 year flood elevations in the Park by as much as 0.02 feet (approximately 1/4 inch). We have no objection to this rise. Furthermore, we are in favor of re-defining the FEMA floodway and floodplains as propoSed by this project. Do not hesitate to call if you have any questions. Sincerely; Director of Public Works Dallas County cc: Bill Blades, Baptist Foundation 411 Elm Street Dallas, Texas 75202 653-7151 /o-P ,/ .] Water Surface Elevation t;l~eck effoctlv~ duplioate-'effeotive revised existing proposed ~;}'~O NCWSI':I '}*('W.~I':I: ~UII(: ' WID. 4 SECNO NCWSEIfi FCWSEI? SURC.'~ WID. 4. SECNO NCWSEI) ~FCWSEI.~ SUIIC' WID. 4 SECNO NCWSEI.~ FCWSEIJ Si~IIC ' WID. 4 ~ ~ 2,0 qeb,q~ q¢~.9o 0,33 l,// ...~ fi, 5 5oL~l FoL52 8,~7 ',om mellts: I~ ¥~lr (flilurull Wul[,r ~llr(;l~ i' } I(.~ ;11i1111 2 ~ ,14'r(i;lc'lllllt'fll (floodway) Wller 5urfuce Elevation 3 - ~urcbarge Vulue 4-Fleedwly Width Water Surface Elevation (:lieck ®ff®°tlve duplloate.'®ffeotlvl, revised exllting 'proposed ~' yO NCWSI.:I.~ I.'CWSt:l ~ SUII('' WID. 4 SECNO NCWSELI FCW~IEI? SUIIC.a WlD. 4. ~£CNO NCWSEI.I FCWSEI.: SUIIC:' WID. 4 SECNO NCWSEI.~ I.'CWSI.:I ~ SUIIC ' WID. 4 ? ~ ~,,0 ffo/.O(:, 5-o1.(_o3 0,5'2' 1/,,o G.O 5'00.?3 5--0453 0.0o /(~0 ;0/305o2,/~~o,7,.e_g o. Tff/zff'30/30 50~.lC/ fo2.?$~,75'/:27 3o130ff'03)'~ 5-03,?0-,of l 9-7 XO/$O5-&3,7,q, 5-03/v[-'-,O(v /527 :o m melt I00 yelr (nlilurull W~il(.r ~t. ll'l.tt I' I' It'~ ;,Itl,l! '~ I' n('r,la('h,,J(.nl 4fl.odway) Wller Suffice [levation 3 - ~urcbarge Vulue 4-Fleedwly Width Water Surface l,',levatiol~ Cl~cck e~ie=tive duplicate effective revised exllting propoted · '~'N() N('WS} I ~ [ I'~'S} I" SI~III' ' WlD. 4 S}:CNO NCWSEi.~ FCWSEI? SUII{:.'~ WlO. 4. SECNO NCWgEI.~ FCWSEI: SUll(' ' WlO. 4 NE(:NO NCWS}:I.' flTWS}:l z SIIII(' ' WlO. 4 ,-~ ~ ~, ~ ~Ol, ~i ~ol,57 0, 2 ~ 3oo ~ ~ ~ ~, I~/,E~ Eol, gl ~,~ ~o ...... - ~ g,~l, fOl,YZ gOl,~ O,~5 I0O ~1 ~.. ~ . .. &, 0~-O/'v~ ~ol,~z 0,57[&o ~.DdOO. gq ~o1,~ 0,~ /~0 ~ IlK) }'cur (nliltlrnl) U,';it,., ~t~rf.,, ~. } I~,~ :,tHm '2 F ,H'rs~;,('h,,H'~tt (~oodway) W.,ler Surf.ce Elev'-,lion 3 - Surcharge Vulue 4-Fllldwly Width ,'°~'z/- ,/2' Water Surface Elevation Check - ~Cilve duplloBt$tffeotiv$ reviied existing p~opoled Nt~NO NCWSt:I~ t'(*WSi:l: Sllll(' ' WID. 4 SECNO NCW~ELs FCW~EI? ~UI/C.:~ WlO, 4. SECNO NCW~EI? FCWSEI? SUIIC' WID, 4 SECNO NCW~EI.~ t:CWSEI.~ SUIIC.' WID. 4 ~o~gl fo~.q2 9o~,g O,FR ~0 Bo~oL ~2.~ 5b~.% 0,5~ ~0 3o~! yoU. Il ~og/7 0,07 ?0 ~o~1 '~o<o? ~ow./~ O, of ?0 ~ 'omments: I I~ yeIr 4nalurul) Wuler Ni~rfa, ~' }lt.~ aI~o,i 2 ~ m'ri);ichmcnt (floodway) Wiier Surface Elevalion 3 - ~urcbarge Value 4-Yleldwly Wldlh Water Surface l",levati()tt (~hcck effectlv& dupilc)ate effective revised exlltl.g P~oPose~ I~ )'t'ur (nulurlillWuls., Surf.e, r } Irx :;t*,,*, '2 [ m'rt~:u'hmcntlfluodwayiWalerSuriece~ievalion 3 · ~urcbarge Value 4-Floodway Width