Loading...
Alexander Ct-SY 971113N ^C*I. DOWDEY, ANDERSON AND ASSOCIATES, INC. [LE U TEW° (11F TQ,�4 RS U1�1 MAIL CIVIL ENGINEERS 5225 VILLAGE CREEK DRIVE SUITE 200 PLANO, TEXAS 75093 (972) 931-0694 FAX (972) 931-9538 TO N� DATE + I JOS ATTENTION 6g.1 , 'j RE. M ST � WE ARE SENDING YOU 'tib Attached ❑ Under separate cover via GOL'r Ie_r the following items: ❑ Shop drawings ❑ Prints O Plans ❑ Samples ❑ Specifications ❑ Copy of letter ❑ Change order COPIES DATE NO. DESCRIPTION As requested bl/�4Ta'iC Wt O FOR BIDS DUE l//s`E - ISR-ol�D s Ei7 — ifs f/GT L2 /1tiDOE�- ,f L fit "V E A-- ' eY F(/ 6/ T OA/ 6 2 A d NG _FL_00ppLAiiV THESE ARE TRANSMITTED as checked below: ❑ For approval ❑ For your use As requested For review and comment O FOR BIDS DUE REMARKS ❑ Approved as submitted ❑ Approved as noted ❑ Returned for corrections 19 ❑ Resubmit copies for approval ❑ Submit copies for distribution ❑ Return corrected prints ❑ PRINTS RETURNED AFTER LOAN TO US Pep- pla xwo u s") COPY TO SIGNED: . Q7) P100 M3 ®"_6'" am 014)1 If anciosuras are not as noted, kindly notify us at Once. Proposed East Tract - Baptist Foundation Tract Coppell, Texas HYDRAULIC MODELING August 31, 1995 Graham Associates 616 Six Flags Dr. #400 Arlington, Texas �jO A Kl IT A -[ ""Pe �2 t N G►S 5 v A4 *l 100 YEAR WATER SURFACES SEC. NO No Duplicate Existing Proposed Effective Natural Floodway Natural Floodway Natural Floodway Lower 27400 494.69 495.34 494.69 495.34 494.69 495.34 27540 494.67 495.57 494.67 495.57 496.67 495.57 27570 494.92 495.68 494.92 495,68 494.92 495.68 27620 495.61 495.72 495.61 495.72 495.61 495.72 1.0 496.24 496.57 496.24 496.57 496.24 496.57 2.0 496.46 496.80 496.46 496.80 496.46 496.80 2.5 496.61 496.97 496.61 496.97 496.61 496.97 3.0 497.62 497.82 497.62 497.82 497.58 497.82 3.3 499.01 499.14 499.01 499.14 499.01 499.14 3.6 499.36 499.57 499.36 499.57 499.35 499.57 4.0 499.91 500.17 499.91 500.17 499.91 500.12 4.5 501.31 501.57 501.31 501.57 501.27 501.45 Main ""0 4.50 501.31 501.57 501.31 501.57 501.27 501.45 01--3 5.00 501.54 501.90 501.54 501.90 501.51 501_.73 5.10 501.54 501.89 501.54 501.89 501.52 501. +.�c 5.11 501.56 501.90 501.56 501.90 501.53 501.73 5.12 501.56 501.92 501.56 501.92 501.53 501.75 5.13 501.56 501.92 501.56 501.92 501.53 501.75 5.14 501.56 501.91 501.56 501.91 501.53 501.74 <o- 5.20 501.56 501.91 501.56 501.91 501.53 501.74 s-vi51 5.21 501.54 501.88 501.54 501.88 501.51 501.71 5.22 501.57 501.94 501.57 501.94 501.54 501.77 5.23 501.57 501.95 501.57 501.95 501.54 501.78 5.24 501.55 501.91 501.55 501.91 501.52 501.74 5.30 1501.45 501.78 501.45 501.78 501.42 501.78 x,05 6.00 500.93 501.53 500.93 501.53 501.01 501.40` `037430130 503.72 503.66 503.72 503.66 503.72 503.59 Bypass SJR � 4.5 501.31 501.57 501.31 501.57 501.27 501.45 70 501.31 501.49 501.31 501.49 501.13 501.22 76 , 501.29 501.61 501.27- 501.50 80 501.33 501.70 501.34 501.70 501.32 501.56 90 501.57 501.94 501.58 501.93 501.56 501.87 110 8; 501.87 502.28 501.88 502.28 501.91- 502.23' Svl.ob 6.0 500 500.93 501.53 500.94 501.53 501.00 501.42- So3,-1430130 Sbrt,'73 503.72 503.66 503.72 503.66 503.72 503.59 Upper 30130 503.72 503.67 503.72 503.66 503.72 503.59 30189 503.58 503.65 503.58 503.64 503.57 503.58 30190 503.45 503.53 503.45 503.52 503.44 503.45 30200 503.69 503.75 503.69 503.75 503.68 503.68 30201 504.09 504.15 504.09 504.14 504.08 504.09 30250 504.99 504.95 504.99 504.94 504.98 504.89 31310 506.56 506.83 506.56 506.83 506.56 506.80 r minsunily Milne: //'' / O IloullingSource: Jc,g V b 1° � re- e- /c PiojectnrmeilJcnlifier: G O e V .40 -�,QfT -I 111 177 - II .►; 19 1993 Water Surface" Wit Che-CIt effoctiv• duplicate- 'off ective revised existing proposed hv ;►t orn 1-1-99fiq CFF_Fi5_F1✓ b-/-93 RfV_`w3_[.owR s-��93 S,? as Rev. eX ti U Nl MtiF.1' YC"El" ` snNc' MIID. NCXBELI FCXSEL' SUNC' NIO. 1. SECNO NCXBEL' FCXSt .` SUNG' It11D. 4 SECNU NCw8e1.' i'CwSE1.` SUM'.' wID. 4 X7070 WPO y92,82 0,39 /,2 4/Q.y3 W2.92 0.39' /At/ ?7Yo0 N9y.G`l ,3q 0,(0( �f l S �t94.(vq y9S3S D.�b y/� 27 0'19.4 S.3 0,65 y /5 f - 75y0 q,?4,G7 y9S57 o•q 1 373 Y9y.b7 �f9f57 0.4/ 373 275- M, (o g7157 .9'0 373 �- 17.570 y9y•91 49,�,69 0,77 37� 27570 k9y,9/ �f9S.&0.77 37 el �75To 49 92 �f9 .b8 D.76 373 �- !7670 y950 YK29 0,/2 yyIf 76 W540 #9S.7z 0./2 qqel7G 111.4-.61 q9S.72 0.1/ 1/4(- 496.2 4% .57 0.32 /60 l' 9 A l 0.33 / / - r '� —� .6 q?(017 0.36 ef,6 1197,R2 0,00 /10 35 �-- F ` — -- .7�f 0.13 125 �r-7L O /30 F- Comments: I_ 100 year Inaturall W;.Irr S'.0a r 1 lr. m..... z l n,-ruarlunent mawwaylw.Ier Surface Elevation 3 Surorarge value 4-Floodw.F Width I , G e.ftv\ Attached are exhibits and computer runs that support a LOMR application to update the effective FIRM's floodplain and floodway limits in the reach of Grapevine Creek that extends from Denton Tad Road to Bethel Road. Graprevine Creek 900 -yr Water Surface Elevations (ft) River Sta. Natural Encroached Q Total cfs HEC -2 Duplicate Effective HEC -RAS Imported HEC -RAS Modified HEC -2 Duplicate Effective HEC -RAS Imported HEC -RAS Modified 22600 11800 479.02 479.02 479.02 479.80 479.80 479.80 24000 11800 482.23 483.06 25000 11800 482.88 483.73 25100 11800 483.26 484.06 25370 11800 486.74 486.89 484.51 487.52 487.52 485.06 25470 11800 1 487.25 487.54 485.66 488.18 488.32 486.04 25485 Denton Ta 25500 11800 488.08 488.43 485.81 488.72 489.00 486.19 25550 11800 488.72 488.47 485.44 488.95 485.85 25685 11900 485.51 485.92 25725 11900 485.97 486.31 25820 11900 486.95 487.15 26170 11900 487.02 487.34 26300 11900 487.29 487.6 26700 11900 488.05 488.27 26880 11900 491.22 491.33 489.77 489.16 491.81 489.82 27050 10500 490.14 490.33 27400 10500 494.03 494.10 492.83 491.83 494.52 1 492.83 27540 10500 494.23 494.37 492.16 494.57 494.91 492.16 27555 Bethel Road 27570 10500 494.43 494.68 493.54 495.00 495.13 493.54 27620 10500 494.65 494.70 494.36 495.14 494.90 494.37 27900 10500 496.58 496.59 30130 10500 i502.87 503.31 502.59 1 503.52 1 503.87 502.60 27400. Exhibit 4 is a floodplain work map that shows the location of these cross sections, the effective FIRM, and the proposed 100 -yr floodplain and flood way delineations. Table 1 Grapevine Creek 100 -yr Discharges (cls) River Station Q 27620 10500 26880 11900 25550 11800 III. COMPUTER MODELS Computer models, input and output are included in this report as attachments under report Section VII. The description and file names are as follows: 1. HEC -2 Current Effective Multiple Profile Model........................GRAPE20.DAT 2. HEC -2 Current Effective Floodway Mode.................................GRAPE21.DAT 3. HEC -RAS Imported Multiple Profile Model...............................7026.PRJ-p01 4. HEC -RAS Imported Floodway Model......................................7026.PRJ-p05 5. HEC -RAS Revised Conditions Multiple Profile Model .................7026.PRJ-p03 6. HEC -RAS Revised Conditions Floodway Model ......................... 7026.PRJ-p06 IV. CONCLUSIONS The results obtained by this study are in compliance with the current floodplain criteria for the City of Coppell and FEMA as shown in the summary of results in Table 2. The table shows that, with the Denton Tap bridge replacement and coding cross sections with recent aerial topography, the flood profile is lowered from downstream of Denton Tap Road to upstream of Bethel Road. Tributa?w G-1 ---. of'Grapevine Creek SETHEL ROADIZ ZON SOO Grapevine Creek ZONE X ST, LOUIS T ROAD Req APPROXIMATE SCALE IN FEET 'UOG 0 10CG ' IIIIIIIIIIIIIII llllllllWlU I NATIONAL FLOOD INSURANCE PROGRAM I FIRM 1 FLOOD INSURANCE RATE MAP DALLAS COUNTY, TEXAS AND INCORPORATED AREAS PANEL 155 OF 125 SEE MAP INDEX FOR PANELS NOT PRIM -EDI BETHE f), SCH j; 'ron'AIN<. w ,p CCtOWNITV NiIAREfl PANEL SUFF7 U C7 � y q C COPPELL Ci+� Or egpt)J 0:56 ,i4iNC FVINC C:LY OFF e8(iifio tt5r, G w V;=,4EEK DON CR � z � 4R9nn 9 _ 99 ZONE AE �� MAP NUMBER 48113CO155 1 482 EFFECTIVE DATE: AUGUST 23, 2001 484 484 S 477 rt +� Federal Emergency Management Agency FRPN�IS� Sa, This is an official copy of a portion of the above referenced flood map. It (I GLENDALE DRIVE was extracted using F -MIT On -Line. This map does not reflect changes or amendments which may have been made subsequent to the date on the title block. For the latest product information about National Flood Insurance Program flood maps check the FEMA Flood Map Store at www.msc.fema.gov rn N Table 4. Summary of Discharges (Cont'd) Drainage Area Peak Discharges (Cubic Feet per Second) Flooding Source and Location (Square Miles) 10 -Year 50 -Year 100 -Year 500 -Year GLENN BRANCH At confluence with Little Creek Approximately 3,200 feet below Bear Creek Road Approximately 3,000 feet below Bear Creek Road At Bear Creek Road GRAPEVINE CREEK At mouth At intersection with extension of Cotton Road At Radio Road At State Route 114 HACKBERRY CREEK At mouth Above confluence of Cottonwood Branch Below confluence of South Fork of Hackberry Creek Above confluence of South Fork of Hackberry Creek Below confluence of Mud Springs Creek Above confluence of Mud Springs Creek HALL BRANCH At confluence with White Rock Creek Above right bank tributary approximately 400 feet below Weber Road At upstream limit of detailed study 2.02 3,050 4,200 4,700 5,900 1.67 2,800 3,850 4,300 5,400 1.18 1,900 2,650 2,950 3,700 1.06 1,900 2,650 2,950 3,700 11.48 5,900 8,600 9,700 12,700 5.95 7,300 10,000 11,200 14,200 3.68 5,100 7,000 7,900 9,900 2.77 4,900 6,700 7,500 9,400 21.22 13,300 18,900 21,400 27,700 15.13 9,400 13,400 15,200 19,600 13.66 11,000 15,400 17,300 22,100 10.44 8,200 13,200 14,900 18,900 5.45 8,000 11,000 12,300 15,500 1.76 3,050 4,150 4,600 5,800 2.16 3,150 4,350 4,850 3,650 1.44 2,050 2,700 3,000 3,650 0.39 850 1,100 1,250 1,500 0_0 BASE FLOOD FLOODING SOURCE FLOODWAY WATER -SURFACE ELEVATION WITHOUT WITH I CROSS SECTION DISTANCE WIDTH SECTION AREA MEAN VELOCITY REGULATORY FLOODWAY FLOODWAY INCREASE (FEET) (SQUARE FEET) (FEET PER SECOND) (FEET NGVD) Glenn Branch A 680' 64 576 8.2 636.8 636.8 637.8 1.0 B 1,940' 58 531 8.1 644.4 644.4 645.2 0.8 C 2,750' 55 343 8.6 650.4 650.4 651.2 0.8 D 3,670' 69 464 6.4 658.7 658.7 659.6 0.9 E 5,100' 130 479 6.2 688.9 688.9 689.9 1.0 Grapevine Creek A 8,5002 300 1,778 5.5 439.6 438.5' 438.5' 0.0 B 12,9002 940 3,141 3.1 448.0 448.0 448.5 0.5 C 14,1702 470 2,079 5.3 453.0 453.0 453.8 0.8 D 16,5432 638 4,624 2.4 461.5 461.5 462.3 0.8 E 20,700' 370 3,063 3.9 471.5 471.5 472.3 0.8 F 22,7002 200 1,566 7.5 478.0 478.0 478.4 0.4 G 24,000' 349 2,498 4.7 482.5 482.5 482.9 0.4 44- 26,9212 145 1,510 7.9 491.2 491.2 491.8 0.6 1 32,1802 119 1,301 8.1 506.7 506.7 507.1 0.4 Tributary G-1 of Grapevine Creek A 9454 137 777 4.0 493.7 493.7 493.7 0.0 B 3,1254 82 432 7.3 499.5 499.5 499.7 0.2 'Feet above mouth 'Feet above confluence with Elm Fork Trinity River 'Elevation computed without consideration of flooding from Elm Fork Trinity River 4 Feet above confluence with Grapevine Creek T A FEDERAL EMERGENCY MANAGEMENT AGENCY FLOODWAY DATA B L DALLAS COUNTY, TX GLENN BRANCH - GRAPEVINE CREEK E AND INCORPORATED AREAS TRIBUTARY G-1 OF GRAPEVINE CREEK $oil!