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Home My WebLink About75 DP Castlegate Sec 2 Ph 1 00-500079((~ COlllC.l STATION DEVELOPMENT PERMIT PERMIT NO. 500079 DP-CASTLEGA TE SUB SEC 2 PH 1 FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE ST A TI ON CITY CODE SITE LEGAL DESCRIPTION: CASTLEGA TE SECTION 2, PHASE 1 DATE OF ISSUE: January 05 , 2001 OWNER: WALLACE PHILLIPS GREENS PRAIRIE INVESTORS , LTD . 5010 AUGUSTA COLLEGE STATION , TE XAS 77845 SITE ADDRESS: 2270 GREENS PRAIRIE RD W DRAINAGE BASIN: SPRING CREEK VALID FOR 12 MONTHS CONTRACTOR: TYPE OF DEVELOPMENT: FULL DEVELOPMENT PERMIT SPECIAL CONDITIONS: All construction must be in compliance with the approved construction plans All t rees must be barricaded, as shown on plans, prior to any construction. An y trees not barricaded will not count towards landscaping points. Barricades must be l ' per caliper inch of the tree diameter. The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition , placement and state . The Owner and /or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion , siltation or sedimentation resulting from the permitted work . An y trees required to be protected by ordinance or as part of the landscape plan must be completely fenced before an y operations of this permit can begin. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station , measures shall be taken to insure that debris from construction , erosion , and sedimentation shall not be deposited in city streets , or ex isting drainage fa cilities . I hereby grant this permit for development of an area outside the special flood hazard area. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit a pplication for the above named project and all of the codes and ordinances of the City of College Station that apply . Date p/~t(29-t2/ STAFF REVIEW COMMENTS No. 2 Project: CASTLEGATE SUB SEC 2 PH 1 (FP)-FINAL PLAT (0-216) PLANNING 1. Final Plat-ok Reviewed by: Ted M~ Date : 12/27/00 ENGINEERING 1. Construction Documents-Everything is ok . 2 . Drainage Report-Everything is ok . 3. Engineer's Estimate-ok Reviewed by: Ted~ Date: 12/27/00 NOTE: Any changes made to the plans, that have not been requested by the City of College Station , must be explained in your next transmittal letter and "bubbled" on your plans . Any additional changes on these plans that have not been pointed out to the City, will constitute a completely new review. Staff Review Comments Page 1 of 1 { "\ ENGINEER'S COST ESTIMATE CASTLEGATE SUBDIVISION COLLEGE STATION, TEXAS SECTION 2 -PHASE 1 Item Estimated No. Description Quantity Sitework 1 Mobilization/Layout 1.0 2 Erosion /Seeding/bale dams/constr. Entr. 1.0 3 Site Preparation 2.5 4 Topsoil Stripping & Replacement 2,000 5 Excavation/Grading 9,100 6 Lime Stabilized Subgrade 6,500 7 Concrete Curb and Gutter 4,400 8 Base Material -6" depth 6,000 9 Base Material -7" depth 0 10 Asphalt Paving -1 1 /2" depth 6,000 11 Concrete Apron 2,000 Storm Drainage 12 18" RCP -structural backfill 27 13 24" RCP -structural backfill 344 14 24" RCP -non-structural backfill 257 15 27" RCP -structural backfill 35 16 27" RCP -non-structural backfill 117 17 36" RCP -non-structural backfill 140 18 Junction boxes 2 19 Inlets 5' wide 0 20 Inlets 1 O' wide 3 21 Inlets 15' wide 4 22 Rip Rap at Road End 120 23 Channel Excavation 1,600 Page 1 of 2 07-Dec-OO Unit Estimated Price Cost LS $10,000.00 $10,000 .00 LS $10,000.00 $10,000 .00 AC $5,000.00 $12,500.00 CY $4.00 $8,000.00 CY $3.50 $31,850.00 SY $3.00 $19,500.00 LF $7.00 $30,800.00 SY $5.75 $34,500.00 SY $6.50 $0.00 SY $4.25 $25,500.00 SF $5.00 ~10,000.00 Subtotal $192,650.00 LF $36.00 $972.00 LF $42.00 $14,448.00 LF $32.00 $8,224.00 LF $46.00 $1,610.00 LF $36.00 $4,212.00 LF $50.00 $7,000.00 EA $2,500.00 $5,000.00 EA $2,500.00 $0.00 EA $3,200.00 $9,600.00 EA $4,000 .00 $16,000.00 TN $40.00 $4,800.00 Cy $3.00 ~4,800.00 Subtotal $76,666.00 REVIEWED FO Cf' ,, I I/\ ICE DEC 2 7 2000 C OLLE.bl:: c 1A1 lu ENGINEERING Waterline 24 8" Waterline -PVC-Cl 200 (C900)-structural back 25 8" Waterline -PVC-Cl 200 (C900)-non-structural 26 Gate Valves -8" 27 M.J . Bends and Tees 8" 28 Connect to Existing 29 Water Services 30 Fire Hydrant Assembly 31 2" Blow off Assembly Sanitary Sewer 32 8" SOR 26 Pipe (10-14') 33 6" SOR 26 Pipe -6-8' depth 34 Tie-in to existing Manhole 35 Construct drop to existing manhole 36 Sewer Services 37 6" Stack Pipe Riser 38 5' Stub out@ -Manhole 39 Manholes -10-12' depth Page 2 of 2 200 LF $30.00 1,740 LF $26.00 5 LF $600 .00 11 EA $300.00 2 EA $350.00 18 EA $700.00 3 EA $2,000.00 3 EA $400.00 Subtotal 1,487 LF $30 .00 1,271 LF $20.00 2 LF $300.00 2 LF $500.00 14 LS $600.00 14 LS $250.00 2 LS $400.00 14 EA $2,200 .00 Subtotal Total Sitework Total Storm Drainage Total Water Total Sanitary Sewer TOTAL CONSTRUCTION Engineering @5% Contingency @5% TOTAL CONSTRUCTION $6,000.00 $45,240.00 $3,000 .00 $3,300.00 $700.00 $12,600 .00 $6,000 .00 ~1,200.00 $78,040.00 $44,610.00 $25,420.00 $600.00 $1,000.00 $8,400.00 $3,500.00 $800.00 ~30,800.00 $115, 130.00 $192,650.00 $76,666.00 $78,040.00 $115, 130.00 $462,486.00 $23,124.30 $23,124.30 $508, 734.60 Scale = 1: 377 Feet 3 24 23 22 42 40 38 37 - 3 4 5 6 7 8 1 N 86 ° 50' 18" E 307 .38 2 S 3° 19' 47" E 375.35 3 S 5° 12' 37 " E 104.44 4 S4°16"W154.89 5 S 9° 33' 9" W 130 .94 6 s 21 ° 29' 42" w 147 .37 7 S 70 ° 12' 52" E 120.85 8 S22°40'16"W111.46 9 S 66 ° 17' 46 " W , ch 34.41 , r 25 R 10 s 17 ° 59' 53" w 60 .03 11 S 28 ° 52' 9" E, ch 33.03 , r 25 R 12 S 5° 20' 29"W, ch 121 .72 , r490 L 13 S1 °47'37"E13.85 14 S 43 ° 3' 8" W , ch 35 .26 , r 25 R 15 S 66 ° 9' 15" W , ch 359 .34 , r 485 L 16 S44°24'37"W134.93 17 N 88 ° 28' 20" W, ch 36 .64 , r 25 R 18 N 45 ° 44' 2" W , ch 105 .37 , r 690.00 L 19 N 51 ° 17' 29" W , ch 20 .56 , r 500 L 20 N 11 ° 36 ' 47"W, ch 32 .71 , r25 R 21 N 60 ° 12' 35" W 50.43 22 N68°26'44"W131 .14 23 N 24 ° 18' 53" E 74 .69 24 N 7° 54' 30" E 66.48 25 N 11 °26'44"W79.27 26 N 72 ° 20' 36" E 49 .81 27 N 17 ° 39' 38" W 60.00 28 N 24 ° 41' 24" W 134 .82 29 N 53 ° 15' 23" E 71 .91 30 N 35 ° 27' 15" E 93 .33 31 S 80 ° 21' 14" E 86 .01 32 S 77 ° 10' 37" E 89 .83 33 N 80 ° 50' 18" E 101 .38 34 N3°53'19"E31.77 35 N 30 ° 42' 32 " E 120 .91 36 N 23 ° 45' 34" E 65.45 37 N 4 ° 16" E 159 .55 38 N 4 ° 39' 47" E 73.48 39 N 60 ° 51'W 56.40 40 N 8° 52' 8" E 128.53 41 N 5° 30' 18" E 60 .08 42 N 8° 2' 40" E 138 .57 43 N16°6'11 "W51 .30 c .astlegate Subdivision Section 2, Phase 1 College Station, Texas Developer: Greens Prairie Investors, Ltd. By Greens Prairie Associates, LLC 5010 Augusta College Station, Texas '77845 (979) 693-7830 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 690-7711 CERTIFICATION I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Texas , certify that this report for the drainage design for the Castlegate Subdivision, Section 2 , Phase 1 was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof _,,,,,,, --""\~OF ?'. \\ ~~!>-••••••••• ~~ , .. 1'"7 •• *•• 1 "")1 Va '* .. ·· ·· .. <J> '• '-*: ···' ~·············· ~ * ~ ~ JOSEPH ••••••....••••.•.•••. rd '~\ .......... f: .. ~£~.V.~!.~ ... .J ~ 0. L\ 65889 //J:iJ ... ;..{\ •~T~ Q • ;;;' ' . t,~;~.~~~.If.~~··;~'l \\~~ONAL ~~--~~-- ll-z.1--ou REVIEWED FOR l COl\,,DI I/\"' 'SE DEC 2 7 2000 COLLE Gt:: ~ ,,..... 1v1-.J ENGINEERING TABLE OF CONTENTS DRAINAGE REPORT CASTLEGATE SUBDIVISION SECTION 2, PHASE 1 CERTIFICATION .................................................................................................................................................................. 1 TABLE OF CONTENTS ........................................................................................................................................................ 2 LIST OF TABLES .................................................................................................................................................................. 3 INTRODUCTION .................................................................................................................................................................. .4 GENERAL LOCATION AND DESCRIPTION .................................................................................................................. 4 FLOOD HAZARD INFORMATION .................................................................................................................................... 4 DEVELOPMENT DRAINAGE PATTERNS ...................................................................................................................... .4 DRAINAGE DESIGN CRITERIA ........................................................................................................................................ 5 STORM WATER RUNOFF DETERMINATION ............................................................................................................... 5 DETENTION FACILITY DESIGN ...................................................................................................................................... 7 STORM SEWER DESIGN .................................................................................................................................................... 7 CONCLUSIONS ..................................................................................................................................................................... 8 APPENDIX A .......................................................................................................................................................................... 9 Storm Sewer Inlet Design Calculations APPENDIX B ........................................................................................................................................................................ 11 Storm Sewer Pipe Design Calculations APPENDIX C ........................................................................................................................................................................ 25 Temporary Drainage Channel Design Calculations EXHIBIT A ............................................................................................................................................................................ 29 Offsite Infrastructure Plan for Castlegate Subdivision EXHIBIT B ............................................................................................................................................................................ 31 Post-Development Drainage Area Map 2 LIST OF TABLES TABLE 1 -Rainfall Intensity & Time of Concentration Calculations .............................................. 6 TABLE 2 -Post-Development Runoff Information ............................................................................ 6 3 DRAINAGE REPORT CASTLEGATE SUBDIVISION SECTION 2, PHASE 1 INTRODUCTION The purpose of this report is to provide the hydrological effects of the construction of the Castlegate Subdivision, Section 2, Phase 1 , and to verify that the proposed storm drainage system meets the requirements set forth by the City of Co ll ege Station Drainage Policy and Design Standards. GENERAL LOCATION AND DESCRIPTION The project is located on a 162 acre tract located west of State Highway 6 along the north side of Greens Prairie Road in College Station, Texas. This report addresses Section 2, Phase 1 of this subdivision , which consists of 15.71 acres . The site is wooded with the vegetation primarily consisting of oak trees and yaupons. The existing ground elevations range from elevation 310 to elevation 330. The general location of the project site is shown on the vicinity map in Exhibit B. FLOOD HAZARD INFORMATION The project site is loc ated in the Spring Creek branch of the Lick Creek Drainage Basin. The site is locat ed in a Zone X Area according to the Flood Insurance Rate Map prepared by the Federal Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated areas dated July 2 , 1992, panel number 48041 C0205-C. Zone X Areas are determined to be outside of the 500-year floodplain. LJA Engineering & Surveying, Inc. submi tted a Request for Conditional Letter of Map Revision (CLOMR) to FEMA to outline a proposed 100-year floodplain area . This CLOMR No. 00-06-844R was approved by FEMA on 9/8/2000 . The proposed floodplain area does not affect Section 2, Phase 1. Phase 1 will continue to be in a ZoneXArea. DEVELOPMENT DRAINAGE PATTERNS The storm water runoff from the site prior to development flows in one general direction. For Section 2, Phase 1, the acreage flows toward the west-northwest boundary of the tract and into existing drainage channels and Spring Creek and ultimately flows north to the proposed regional detention facility . Refer to the Offsite Infrastructure Plan in Exhibit A for the location of this proposed detention facility . 4 DRAINAGE DESIGN CRITERIA The design parameters for the storm sew er ar e as follows: • The Ration al Method is utili zed to d etermine peak storm water runoff rates for the storm sewer design. • Design Storm Frequency Storm Sewer system • Runoff Coefficients Pre-development 10 and 100-year storm events Post-development (singl e family residential) c = 0.30 c = 0 .55 • Rainfall Intensity values for Brazos County for a minimum time of concentration of 10 minutes can be found in Table 1. Where a longer time of concentration was necessary, it is noted in the respective table , and the intensities are calculated with the higher values where required. • Time of Concentration, tc -Due to the small sizes of the drainage areas, the calculated times of concentration, tc, are less than 10 minutes. Therefore, a minimum tc of 10 minutes is used in most cases to determine the rainfall intensity values . Where a longer time of concentration was necessary, it is not ed and used accordingly. Refer to Table 1 for calculations. ST ORM WATER RUN OFF DETERMINATION The peak runoff values were determined in accordance with the criteria presented in the previous section for the 5, 10 , 25, 50, and 100-year storm events. The runoff coefficients are based on the future development of this tract. The drainage areas for post-development are shown in Exhibit B . Post-development runoff conditions are summarized in Table 2. 5 TABLE 1 -R a in fa ll I ntens ity & T ime of C oncentration Calcul atio ns Rai nfall Int e n s ity Values (i n /hr) St orm t = c Event 10 m i n 15 7 .693 110 8.635 125 9.861 150 11 .148 1100 11 .639 Brazos County: 51'.'.ear storm 10 l'.'.ear storm b = 76 b = 80 d = 8 .5 d = 8 .5 e = 0 .785 e = 0 .763 I = b I (tc+d)0 I = Rainfa ll Intensity (i n/h r) tc = U(V*60) to= Time of co ncentrati o n (min) L = Length (ft) V =Velocity (ft/sec) 251'.'.ear storm 50 l'.'.ear storm 100 l'.'.ear storm b = 89 b = 98 b = 96 d = 8 .5 d = 8 .5 d = 8 .0 e = 0 .754 e = 0 .745 e = 0 .730 (Data taken from State Department of Hiqhwal'.'.S and Public Transportation Hl'.'.drau lic Manual, page 2-16) TABLE 2 - P ost -Deve lopmen t Runoff Information A c t c Q 5 Q 10 Q 25 Q 50 A r ea# (acres ) (min ) (c f s) (c fs) (cfs ) (c fs) 5 1.74 0 .55 1 0 7 .36 8 .26 9.44 1 0 .67 38 2 .27 0 .55 1 0 9 .60 1 0 .78 1 2 .31 1 3 .92 39 1 . 61 0 .55 1 0 6 .81 7 .65 8.73 9 .87 40 1 . 7 8 0.55 1 0 7 .53 8 .45 9 .65 1 0 .91 41 2 .1 3 0 .55 1 0 9.01 1 0 .1 2 11 .5 5 1 3 .06 42 1 .38 0 .55 1 0 5.84 6 .55 7 .48 8 .46 43 1 .36 0 .55 1 0 5.7 5 6 .46 7 .38 8 .34 44 1 .69 0 .55 10 7 .1 5 8 .03 9 .1 7 1 0 .36 49 1 . 7 1 0 .55 1 0 7 .24 8 .1 2 9 .27 1 0 .48 50 1 .06 0 .55 1 0 4 .49 5 .03 5 .7 5 6 .50 58 1 . 1 2 0 .55 1 0 4.74 5 .32 6 .07 6 .87 59 1 .32 0 .55 1 0 5 .59 6 .27 7 .1 6 8 .09 60 1 .50 0 .55 1 0 6 .35 7 .1 2 8 .14 9.20 61 1 . 1 7 0 .55 1 0 4 .95 5 .56 6 .35 7.17 62 1 . 7 5 0 .55 1 0 7 .40 8 .3 1 9 .49 10 .7 3 90 1 .32 0 .55 1 0 5 .59 6.27 7 .1 6 8 .09 6 Q 100 (c f s) 1 1 . 1 4 14 .53 1 0 .31 11 .3 9 1 3 .64 8 .83 8 . 71 10 .82 1 0 .95 6 . 79 7 .17 8 .45 9.60 7 .49 11.20 8 .45 DETENTION FACILITY DESIGN The detention facility handling the runoff from this site will be a regional facility designed by LJA Engineering & Surveying, Inc. Refer to the Offsite Infrastructure Plan in Exhibit A for the location of this proposed detention facility. The runoff from this project flows into existing drainages and then into Spring Creek. The detention facility is located adjacent to Spring Creek prior to Spring Creek entering the State Highway 6 right-of-way. STORM SEWER DESIGN The storm sewer piping for this project has been selected to be Reinforced Concrete Pipe (RCP) meeting the requirements of ASTM C-76, Class III pipe . The curb inlets and junction boxes will be cast-in-place concrete. Appendix A presents a summary of the storm sewer inlet design parameters and calculations . The inlets were designed based on a 10-year design storm. As per College Station guidelines , the capacities of inlets in sump were reduced by 10% to allow for clogging. Inlets were located to maintain a gutter flow depth of 5" or less , which will prevent the spread of water from reaching the crown of the road for the 10-year storm event. The runoff intercepted by the proposed storm sewer inlets was calculated using the following equations. The depth of flow in the gutter was determined by using the Straight Crown Flow equation. The flow intercepted by Inlets 201-206 & 224 was calculated by using the Capacity of Inlets On Grade equation. There are no inlets in sump for this phase of construction. The equation used for on-grade inlets and the resulting data are summarized in Appendix A. Appendix B presents a summary of the storm sewer pipe design parameters and calculations. All pipes are 18" in diameter or larger. For pipes with 18" and 24" diameters, the cross- sectional area is reduced by 25%, as per College Station requirements. A summary of how this was achieved is shown in Appendix B as well. The pipes for the storm sewer system were designed based on the 10-year storm event; however, all will also pass the 100-year storm event without any headwater. Based on the depth of flow in the street determined for the 100-year storm event, this runoff will be contained within the street right-of-way until it enters the storm sewer system. As required by College Station, the velocity of flow in the storm sewer pipe system is not lower than 2 .5 feet per second, and it does not exceed 15 feet per second. As the data shows , even during low flow conditions, the velocity in the pipes will exceed 2.5 feet per second and prevent sediment build-up in the pipes. The maximum flow in the storm sewer pipe system will occur in Pipe No. 206. Appendix B contains a summary of the Manning pipe calculations as well as flow diagrams mapping the flows through the storm sewer system for the 10 and 100-year events. The maximum velocity for the pipe system in Section 2, Phase 1 will be 11.06 feet per second and will occur in Pipe 205 . Pipes 206 & 233 will be stubbed out for this phase of construction. A temporary drainage channel will be constructed from the end of each of these stubbed out pipes. The locations of these channels are shown in Exhibit B. A temporary blanket easement has been provided to the City for the future development of adjacent areas and the construction of off-site drainage and utility facilities . The velocity in Channel No. 1is3 .6 feet per second for the 10-year event, and 3.8 feet per second for the 100- year event. The velocity in Channel No. 2 is 3 .1 feet per second for the 10-year event , and 3 .3 feet per second for the 100-year event. These velocities are within the requirements for a 7 seeded grass channel outlined on page 60 of the City of Co ll ege Station Drainage Policy & Design Standards manual. Refer to Appendix C for details. CONCLUSIONS The construction of this project will significantly increase th e storm water runoff from this site. The proposed storm sewer system should adequately contro l the runoff and release it into existing drainages. Also, the regional detention facility and the proposed ponds in the park area (addressed in Section 1, Phase 1) should adequat ely reduce the peak post-development runoff to less than the pre-development runoff for the design storm event. This will prevent any impact on the properties downstream of this project. 8 APPENDIX A Storm Sewer Inlet Design Calculations 9 Castlegate Subdivision Section 2 -Phase 1 Inlet Length Calculations No Inlets i n sump for this phase. Inlets On Grade Inlet# Length & Type F~wfro m Area# Section 21Phase 1 .,. 201 15' Reces sed 38 202 1 O' Recessed 5 203 10' Recessed 39 204 15' Recessed 62 205 1 O' Recessed 61 206 15' Recessed 60 224 15' Recessed 40 Y10 (ft) (In) 0 .364 4.37 0 .329 3.95 0.380 4.56 0.408 4.90 0.333 3.99 0.355 4.26 0.380 4.56 Transverse (Crown ) slo pe (fVft) = 0 .038 Q JMr foot Q C:llpllClty (fl) (cfs) 0.66 9.85 0.62 6.23 0.66 6.57 0.67 10.03 0.63 6.26 0.65 9.72 0.67 10.10 Stra ight Crown Flow (Sol ved to find actual depth of flow . yl : Q byp ... (cfs) 0.93 2.03 1.07 -1 .72 -0 .70 -2 .59 -1.64 a= o .56 • (zln) • s "' • y'" q y = {Q / (o .ss • (zln) • s 112n'" n =Roughness Coefficient= 0 .018 z = Reciprocal of crown slope = 26 S = StreeVGutter Slope (fVft) y = Depth of flow at inlet (ft ) Capacity of Inlets on grade: Oc = 0 .7 '(1/(H, - H,)] '[H ,512 • H,'"J Oc = Flow capacity of inlet (els) H 1 ~a+ y H2 =a = gutter depression (2" Standard ; 4" Recessed) y = Depth of flo w in approach gutter (ft) 1 O year storm O uptuM Q C.rry'OHr Q byp-tot.i C c9f)t-tot• (cfs ) (cfs) from Inlet# (cfs) (cfs) 9.85 0.00 0.93 9.85 6.23 0.00 2.03 6.23 6.57 0.93 201 2.00 6.57 8.31 2.03 202 0.31 10.03 5.56 0.00 0.00 5.56 7.12 0.00 204, 205 0.00 7.12 8.45 0.00 0.00 8.45 Q 10·T01al y,., (cfs ) (fl) (in ) 10.78 0.407 4.89 8.26 0.368 4.42 8.57 0.461 5.54 10.35 0.478 5.73 5.56 0.372 4.47 7.12 0.475 5.69 8.45 0.425 5.10 100 year storm O i-1oc11 <l.;..,,llClty Obyp•• O uptured (fl) (cfs) (cfs) (cfs) 0 .70 10.50 4 .03 10 .50 0 .66 6.6 1 4.52 6.61 0 .70 7.0 1 3.30 7.01 0 .71 10.71 0.49 10.71 0 .67 6.65 0.84 6 .65 0 .69 10.35 -0 .75 9.60 0.72 10.78 0.61 10.78 In lets in sumps. Weir Flow : L = QI (3 'y312) q y = (QI 3L)213 L = Length of inlet opening (ft) Q =Flow at inlet (els) y = total depth of flow on inlet (ft) ma x y for inlet in sump = 7" = 0 .583' C urry__, (cfs ) from inlet# 0.00 0.00 4.03 201 4.52 202 0.00 5.86 204 , 205 0.00 Q byp..:ot.i O c:119l -toc1 0 100.Tot• s L..e1u., (cfs) (cfs) (cfs) (tuft ) (fl ) 4.03 10.50 14 .53 0.0380 15 ,____ 4.52 6.61 11 .14 0.0380 10 7.33 7.01 14 .33 0.0190 10 5.02 10.71 15.73 0.0 190 15 0.84 6.65 7.49 0 .0 163 10 5.11 10.35 15.46 0 .0190 15 0.61 10.78 11 .39 0.0185 15 APPENDIXB Storm Sewer Pipe Design Calculations 11 Castlegate Subdivision Pipe Calculations -Section 2 , Phase 1 Inlet Outlet 10 yea r storm 100 year storm Pipe# Size Length Slope Invert Invert Elev Elev *Actual Flow Design Fl ow V10 % Full Travel Time , lT1o *Actu al Flow Desig n Flow V100 % Full (in) (ft) (%) {ft) {ft) {cfs) {cfs) (fps) {sec) (min) {cfs) (cf s) (fps) 200 24 30 .9 0 .60 314.81 3 14 .62 9 .85 15 .91 5.9 0 80 .0 5 0 .09 10 .50 16.96 5 .88 86.4 201 24 99 .8 1.50 313.65 312.15 16 .08 25.97 9.33 82 .8 11 0 .18 17 .11 27.63 9 .12 92.3 202 24 156.9 1.50 31 1.48 309.13 16 .08 25 .97 9 .33 82 .8 17 0 .28 17 .11 27 .63 9 .12 92.3 203 18 27.0 1.20 309 .95 309 .63 6 .57 10.6 1 6 .89 8 1.3 4 0 .07 7 .0 1 11 .32 6 .82 88 .8 204 27 94 .2 1.30 308 .85 307 .63 32 .68 9.40 81 .7 10 0 .17 34 .83 9 .29 89 .3 205 27 57 .2 1.80 307 .56 306.53 38.24 11 .06 81 .2 5 0 .09 41.48 10.77 92 .9 206 36 139.4 0 .65 305.78 304 .87 45 .36 8.00 74 .8 17 0 .29 51 .83 8.02 85.9 232 24 181 .3 1.75 305 .28 302.11 8.45 13.65 8.81 49 .5 21 0 .34 10 .78 17.41 9 .34 57.4 233 24 130.5 2 .00 308 .01 305.40 8 .45 13.65 9.26 47.6 14 0 .23 10 .78 17.41 9 .83 55.0 *These values reflect th e actual flow for the 18" & 24" pipes . The desig n flow for these pipe sizes reflects a 25% reduction in pipe area . (Refer to attached calculation for specific information .) Travel Time , 11100 (sec) (min) 5 0 .09 11 0 .18 17 0 .29 4 0 .07 10 0 .17 5 0 .09 17 0 .29 19 0 .32 13 0 .2 2 City of College Station requirement to Reduce Cross-Sectional Area of 18" & 24" Pipes by 25% Using Mannings Equation from page 48 of the College Station Drainage Policy & Design Standards Manual : Q = 1.49/n * A * R213 * S 112 Q =Flow Capacity {cfs) 18" Pipe: Pipe size (inches) = Wetted Perimeter W P, (ft)= Cross-Sectional Area A , (W) = Reduced Area A R, (ft2 ) = Hydraulic Radius R = A/WP• (ft) = Reduced Hydr Radius RR = A R/WP• (ft) = Roughness Coefficient n = Friction Slope of Conduit Sr. (ft/ft)= Example Calculation: Slope Flow Capacity Reduced Flow Ca paci ty s Q 0 .005 6 .91 0.006 7.57 0 .007 8 .18 24" Pipe: Pipe size (inches) = Wetted Perimeter W P, (ft)= Cross-Sectional Area A , (W) = Reduced Area A R, {W) = Or educed 4.28 4.69 5.06 Hydraulic Radius R = A/WP• (ft) = Reduced Hydr Radius RR = A R/W P• (ft) = Roughness Coefficient n = Friction Slope of Conduit Sr. (ft/ft) = Example Calculation: Slope Fl ow Capacity Reduce d Fl ow Ca pacit y s Q Oreduced 0 .005 14 .89 9 .22 0.006 16.31 10 .1 0 .007 17 .61 10 .9 Conclusion : 18 4 .71 1.766 1 .325 0 .375 0 .281 0 .014 0.01 % Difference Oreduced /Q 0.619 0.619 0.619 24 6.28 3 .14 2 .355 0 .5 0 .375 0.014 0 .01 % Difference OreduceiO 0.619 0.619 0.619 Multiply actual Q in 18" & 24" pip es by 1.615 to reflect a 25% reduction in the cross-sectiona l area called for on page 47, paragraph 5 of the College Station Drainage Policy & Design Standards manual. Castlegate Subdivision Section 2, Phase 1 -Pipe Flow Diagram Inlet 201 I 9 .85 J., Pipe 200 1 9.85 J., Inlet 202 1 6.23 J., Pipe201 I 16.08 J., June Box 200 J., Pipe 202 1 16 .08 J., Inlet 204 1 10 .03 J., Pipe 204 1 32 .68 J., Inlet 205 1 5.56 J., Pipe 205 1 38 .24 J., Inlet 206 1 7 .12 i llPipe 206 1 45.36 11 (Into Phase 2) 010 (cfs) Inlet 203 6.57 J., ---1 ~ Pipe 203 6.57 Inlet 224 1 8.45 J., Pipe 233 1 8.45 J., June Box 209 llP ipe 232 1 8.45 II (Into Phase 2) Castlegate Subdivision Section 2, Phase 1 -Pipe Flow Diagram In let 201 I 10 .50 J, Pipe 200 1 10 .50 J, Inlet 202 1 6.61 J, Pipe201 l 17 .11 J, J un e Box 200 J, Pipe202 l 17 .11 J, Inlet 204 1 10 .71 J, Pipe 204 1 34 .83 J, Inlet 205 1 6.65 J, Pipe 205 1 41.48 J, Inlet 206 1 10.35 J, llP ipe 206 1 51.83 11 (Into Phase 2) 0 100 (cfs) Inlet 203 1 7 .01 J, Pipe 203 1 7.01 Inlet 224 1 10 .78 J, Pipe 233 1 10 .78 J, Ju ne Box 209 llPipe 232 1 10 .78 II (Into Phase 2) Pipe 2 00 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . S o l v ing for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 2 4.0000 in 15.9100 cfs 0.0060 ft/ft 0. 0140 19.2062 in 3.1416 ft2 2 .6951 ft2 53.1588 in 75.3982 in 5.9032 fps 7.3007 in 80 .0 2 60 % 16 .2716 cfs 5.1794 fps Pipe 200 -100 Year Storm Manning Pipe Calculator Giv en Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 24.0000 in 16.9600 cfs 0.0060 ft/ft 0. 0140 20.7336 in 3 .1416 ft2 2 .8850 ft2 57.2616 in 75.3982 in 5.8786 fps 7 .2552 in 86.3 899 % 16 .2 71 6 cfs 5 .1 79 4 fps Castlega t e Subdiv i s i o n, Section 2 , Ph ase 1 College Stati o n, Texas Pipe 201 -10 Year Sto rm Manning Pipe Calculator Giv e n Input Data: S hape .......................... . Solv ing for .................... . Diameter ....................... . F l owrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circul ar Depth of Flow 24 .0000 in 2 5 .9700 cfs 0.0150 ft/ft 0 .0140 19.8826 i n 3 .141 6 ft2 2.78 2 8 ft2 54 .89 9 4 in 75 .3982 in 9.33 2 5 fps 7.2991 in 82 .844 2 % 25.7 2 76 cfs 8 .189 4 fps Pipe 201 -100 Year Storm Manning Pipe Cal c ulator Giv en Input Data: Shape .......................... . Solv ing for .................... . Diameter ....................... . Flowrate ....................... . S l ope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Pe rc e nt Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circ ular Depth o f Flow 24 .0000 in 27 .6300 cfs 0.015 0 ft/ft 0. 014 0 22 .1468 in 3 .1416 ft2 3.0 2 98 ft2 61 .88 2 0 in 75 .39 8 2 in 9. 11 93 fps 7 .0505 in 92.27 8 2 % 2 5 .7 276 cfs 8 .18 9 4 fps Ca s t legat e Subd ivi s i o n, Sec t ion 2 , Phase 1 Co l lege Stat ion, T exas Pipe 2 0 2 -10 Year Storm Manning P i pe Calculator Giv en Input Data: Shape .......................... . S o l v ing for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Depth .......................... . Area ............. .' ............ · · Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24 .0000 in 25 .9700 cfs 0.0150 ft/ft 0. 0140 19.8826 in 3.1416 ft2 2.7828 ft2 54.8994 in 75.3982 in 9.3325 fps 7.2991 in 82.8442 % 25 .7276 cfs 8.1894 fps Pipe 202 -100 Year Storm Manning Pipe Calculator Giv en Input Data: Shape .......................... . Solv ing for .................... . Diameter ....................... . Flowrate ....................... . Slope ......... · ................. . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 24.0000 in 27.6300 cfs 0.0150 ft/ft 0. 0140 22.1468 in 3 .1416 ft2 3.0298 ft2 61.8820 in 75 .3982 in 9. 1193 fps 7.0505 in 92 .278 2 % 25.727 6 cfs 8.18 9 4 fps Castlegate Subdiv ision, S ect ion 2 , Pha s e 1 Co l leg e Statio n, Texa s Pipe 203 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area .......................... · · Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloci ty ....................... . Hydr aulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 18.0000 in 10.6100 cfs 0.0120 ft/ft 0. 0140 14.6397 in 1.7671 ft2 1.5392 ft2 40 .4645 in 56.5487 in 6.8932 fps 5.4775 in 81.3318 % 10.6850 cfs 6.0465 fps Pipe 203 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full fl ow veloc ity ............. . Circular Depth of Flow 18.0000 in 11.3200 cfs 0.0120 ft/ft 0. 0140 15 .988 3 in 1.7671 ft2 1.6589 ft2 44.2775 in 56.5487 in 6.8238 fps 5.3951 in 88.8241 % 10.6850 cfs 6.0465 fps Castlegate Subdivision, Section 2, Phase 1 College Station , Texas Pipe 204 -10 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diame ter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Dept h .......................... . Area ........................... . Wette d Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloci ty ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 27.0000 in 32.6800 cfs 0. 0130 ft/ft 0. 0140 22 .0484 in 3 .9761 ft2 3.4761 ft2 60.9254 in 84 .8230 in 9 .40 12 fps 8.2160 in 81.6607 % 32.7893 cfs 8.2466 fps Pipe 204 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimet er ...................... . Veloci ty ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow veloc ity ............. . Circular Depth of Flow 27.0000 in 34.8300 cfs 0.0130 ft/ft 0. 0140 24.1144 in 3.9761 ft2 3.7479 ft2 66.8388 in 84.8230 in 9 .2 931 fps 8.0747 in 89.3124 % 32 .7893 cfs 8.2466 fps Castlegate Subdivision, Section 2, Phase 1 College Station, Texas Pipe 205 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Ve locity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Fl ow 27.0000 in 38.2400 cfs 0. 0180 ft/ft 0. 0140 21.9150 in 3.9761 ft2 3.4567 ft2 60.5825 in 84.8230 in 11.0626 fps 8.2163 in 81.1667 % 38.5831 cfs 9.7038 fps Pipe 205 -100 Year Storm Manning Pipe Calculator Give n Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloc ity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 27.0000 in 41.4800 cfs 0.0180 ft/ft 0. 0140 25.0871 in 3.9761 ft2 3.8515 ft2 70.2743 in 84.8230 in 10.7697 fps 7.8922 in 92.9152 % 38.5831 cfs 9.7038 fps Castlegate Subdivision, Sec tion 2, Phase 1 College Station, Texas Pipe 206 -10 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloc ity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow veloc ity ............. . Circular Depth of Flow 36.0000 in 45.3600 cfs 0.0065 ft/ft 0. 0140 26.9121 in 7.0686 ft2 5.6676 ft2 75.1956 in 113.09 73 in 8.0034 fps 10.8535 in 74.7559 % 49 .9330 cfs 7 .0641 fps Pipe 206 -100 Year Storm Manning Pipe Calculator Given I nput Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloci t y ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 36.0000 in 51.8300 cfs 0.0065 ft/ft 0. 0140 30.9114 in 7.0686 ft2 6.4586 ft2 85 .34 56 in 113.09 7 3 in 8.0249 fps 10.8974 in 85 .8649 % 49.9330 cfs 7.0641 fps Castlegate Subdivision, Section 2 , Phase 1 Coll ege Station, Texas Pipe 232 -10 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solv ing for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Mann i ng' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 24.0000 in 13.6500 cfs 0.0175 ft/ft 0. 0140 11.8754 in 3.1416 ft2 1.5500 ft2 37 .4500 in 75.3982 in 8.8062 fps 5.9601 in 49.4810 % 27.7890 cfs 8.8455 fps Pipe 232 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solv ing for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 24.0000 in 17.4100 cfs 0.0175 ft/ft 0.0140 13.7675 in 3.1416 ft2 1 .8643 ft2 41.2470 in 75.3982 in 9.3386 fps 6.5086 in 57.3645 % 27.7890 cfs 8.8455 fps Castl e gate Subdiv ision, Sectio n 2, Phase 1 Coll e ge Station, Tex as Pipe 233 -10 Year Storm Manning Pipe Calculator Gi ven Input Data : Shape .......................... . Solv ing f or .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloc ity ....................... . Hy draulic Radius ............... . Percent Ful 1 ................... . Full flow Flowrate ............. . Full flow veloci t y ............. . Circular Depth of Flow 24.0000 in 13.6500 cfs 0.0200 ft/ft 0. 0140 11.4 2 30 in 3.1416 ft2 1.4747 ft2 36.5446 in 75.3982 in 9.2563 fps 5.8107 in 47.5958 % 29.7077 cfs 9.4563 fps Pipe 233 -100 Year Storm Manning Pipe Calculator Giv en Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrat e ....................... . Slope .......................... . Manning' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 24 .0000 in 17 .4100 cfs 0.0200 ft/ft 0.0140 13.2046 in 3.1416 ft2 l. 7712 ft2 40.1124 in 75.3982 in 9.8293 fps 6.3586 in 55.0193 % 29.7077 cfs 9 .4563 fps Castlegate Subdivision, Sec tion 2 , Phase 1 College Station, Texas APPENDIXC Temporary Drainage Channel Design Calculations 25 Castlegate Subdivision Temporary Drainage Channel Calculations -Section 2, Phase 1 Temporary Drainage Channel No. 1 A c tc 010 Area# (acres) (min) (cfs) 58 1.12 0 .55 10 5 .32 59 1.32 0 .55 10 6 .27 From Pipe 206 : 45 .36 Total Flow to Temp Drainage Channel : 56.94 T emporary D . ramage Ch anne IN 2 0. Area# A c tc (acres) (min) 41 2 .13 0 .55 10 42 1.38 0.55 10 From Pipe 232 : Total Flow to Temp Drainage Channel : The Rational Method: Q=CIA Q =Flow (cfs) A= Area (acres) C = Runoff Coeff. I = Rainfall Intensity (in/hr) 010 (cfs) 10 .11 6 .55 8.45 25.11 0100 (cfs) 7 .17 8.45 51 .83 67.45 0100 (cfs) 13 .64 8 .83 10 .78 33.25 Temporary Dr ai nage Channel No. 1 -10 Year Storm Channel Ca l c u lator Given Input Data: Shape .......................... . Solving for .................... . Flowrate ....................... . Slope .......................... . Manni ng' s n .................... . Height ......................... . Bottom wi dth ................... . Left slope ..................... . Right slope .................... . Computed Results: Depth .......................... . Ve l oc ity ................... · .... . Full Flowrate .................. . Flow area ...................... . Flow peri meter ................. . Hy draulic radius ............... . Top width ...................... . Area ........................... . Perimete r ...................... . Percent full ................... . Trapezoidal Depth of Fl ow 56.9400 cfs 0.0040 ft/ft 0.0 300 42.0000 in 0 .0000 in 0.5000 ft/ft (V/H) 0.5 000 ft/ft (V/H) 33.5718 in 3.6375 fps 103.4703 cfs 15.6537 ft2 150.1378 in 15.0 138 in 134 .2873 in 24.5000 ft2 187.8297 in 79.9329 % Temporary Drainage Channe l No. 1 -100 Year Storm Channel Calculator Given Input Data: Shape .......................... . Solv ing for .................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Height ......................... . Bottom widt h ................... . Left slope ..................... . Right slope .................... . Computed Results: Depth .......................... . Veloc ity ....................... . Full Flowra t e .................. . Flow area ...................... . Flow perimeter ................. . Hydraulic radius ............... . Top width ...................... . Area ........................... . Perime ter ...................... . Percent full ................... . Trapezoidal Depth of Flow 67.4500 cfs 0.0040 ft/ft 0 .030 0 42.00 00 in 0.0000 in 0.5000 ft/ft (V/H) 0.5000 ft /f t (V/H) 35.7735 in 3.7948 fps 10 3.4703 cfs 17.7742 ft 2 159.9840 in 15.9984 in 14 3 .0941 in 24.5000 ft2 18 7.8297 in 85 .1750 % Castl e g ate Subdiv ision, Section 2, Phase 1 Coll ege Stat ion, Texas Temporary Drainage Channel No. 2 -10 Ye ar Storm Channel Calculato r Given Input Data : Shape .......................... . Solv ing for .................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Height ......................... . Bottom width ................... . Left slope ..................... . Right slope .................... . Computed Results: Depth .......................... . Velocity ....................... . Full Flowrate .................. . Flow area ...................... . Flow perimeter ................. . Hy draulic radius ............... . Top width ...................... . Area ........................... . Perimeter ...................... . Percent full ................... . Trapezoidal Depth of Flow 25.1100 cfs 0.0045 ft/ft 0.0 300 36.0000 in 0.0000 in 0.5000 ft/ft (V/H) 0.5000 ft/ft (V/H) 24.1571 in 3.0981 fps 72.7557 cfs 8 .1051 ft2 108 .0338 in 10 .8034 in 96.6284 in 18.0000 ft2 160.99 69 in 67.10 31 % Temporary Drainage Channel No. 2 -100 Ye ar Storm Channel Calculator Given Input Data: Shape .......................... . Solving for .................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Height ......................... . Bottom width ................... . Left slope ..................... . Righ t slope .................... . Computed Results: Depth .......................... . Ve locity ....................... . Full Flowrate .................. . Flow area ...................... . Flow perimeter ................. . Hy draulic radius ............... . Top width ...................... . Area ........................... . Perimeter ...................... . Percent full ................... . Trapezoidal Depth of Flow 33.2500 cfs 0.0045 ft/ft 0 .0300 36 .0000 in 0. 0000 in 0.5000 ft/ft (V/H) 0.5000 ft/ft (V/H) 26.8395 in 3.3233 fps 72 .755 7 cfs 10.0050 ft2 120.0298 in 12.0030 in 107.3 579 in 18.0000 ft2 160 .9969 in 74.5541 % Castlegate Subdiv ision, Section 2, Phase 1 College Station, Texas EXHIBIT A Offsite Infrastructure Plan for Castlegate Subdivision 29 I I I I I I I I I I ' ' , 7? T~B • k I E 1 -Rainfall Intensity & Time of Concentration Calculations ~I A c tc as a1o Q 2S Area# (acres) (min) (cfs) (c fs) (c fs) ,., 5 1 . 7 4 0 .55 1 0 7 .36 8 .26 9.44 /38 2 .27 0 .55 1 0 9 .60 1 0.78 1 2 .31 y-3 9 1 .61 0 .55 1 0 6 .81 7 .65 8 .73 ..r40 1 . 7 8 0 .55 1 0 7 .53 8.45 9 .65 ""41 2 .1 3 0 .55 10 9 .01 10 .1 2 11 .55 ..,...42 1 .38 0.55 10 5 .84 6 .55 7 .48 /43 1 .36 0 .55 10 5 .75 6 .46 7 .38 /44 1 .69 0.55 10 7 .15 8 .03 9 .17 /49 1. 71 0 .55 10 7 .24 8 .12 9 .27 ......s o 1 .06 0 .55 10 4 .49 5 .03 5 . 75 /58 1 . 1 2 0.55 1 0 4 .74 5.32 6 .07 -'$ 9 1 .32 0 .55 1 0 5 .59 6 .27 7 .16 /60 1 .50 0 .55 1 0 6 .35 7 .1 2 8.14 ,...,.-61 1 .17 0 .55 1 0 4 .95 5 .56 6 .35 .,,.. 62 1 . 7 5 0 .55 1 0 7 .40 8 .31 9.49 ....... 90 1 .32 0 .55 1 0 5.59 6 .27 7 .1 6 TABLE 2 -Post-Development Runoff Information A c tc as 010 Q 2S Area# (acres) (min) (c fs) (cfs) (cfs) 5 1 .74 0 .55 1 0 7 .36 8 .26 9.44 38 2 .27 0 .55 1 0 9 .60 10 .78 1 2 .31 39 1 .61 0 .55 1 0 6 .81 7 .65 8 .7 3 40 1 .78 0 .55 1 0 7 .53 8 .45 9 .65 41 2 .1 3 0 .55 1 0 9 .01 1 0 .1 2 11 .55 42 1 .38 0 .55 1 0 5 .84 6.55 7 .48 43 1 .36 0 .55 1 0 5 .7 5 6 .46 7 .38 44 1 .69 0 .55 1 0 7 .1 5 8 .03 9.17 49 1 . 71 0 .55 1 0 7 .24 8 .12 9 .27 50 1 .06 0 .55 1 0 4 .49 5 .03 5.75 58 1 .1 2 0 .55 1 0 4 .74 5 .32 6.07 59 1 .32 0.55 1 0 5 .59 6 .27 7 .1 6 60 1 .50 0 .55 1 0 6 .35 7 .12 8 .14 61 1 .17 0 .55 1 0 4 .95 5.56 6.35 62 1.75 0 .55 1 0 7.40 8 .31 9.49 90 1 .32 0 .55 1 0 5 .59 6.27 7 .16 6 p,,'(J /J. a so a 100 (c fs) (c fs) 10 .67 11 .1 4 13.92 14 .53 9 .87 1 0 .31 1 0 .91 11 .39 13 .06 13 .64 8 .46 8 .83 8 .34 8 .71 10 .36 1 0 .82 10.48 1 0 .95 6 .50 6 .79 6 .87 7 .17 8.09 8 .45 9 .20 9 .60 7 .17 7 .49 1 0 .73 11 .20 8 .09 8 .45 Oso Q 100 (cfs) (c fs) 10 .67 11 .1 4 13 .92 14 .53 9 .87 1 0 .31 1 0 .91 11 .39 13 .06 13 .64 8 .46 8 .83 8 .34 8 . 71 10 .36 1 0 .82 10 .48 10 .95 6 .50 6 .79 6 .87 7 .17 8 .09 8 .45 9 .20 9 .60 7 .17 7 .49 10 .7 3 11 .20 8 .09 8 .45 --- - Castlegate Subdivision Section 2 -Phase 1 Inlet Length Calculations / No Inlets In sump for this phase. Inlets On Gnido Inlet# Length & Type Flow"°"' y,. Area# (ft) (In) Section 21imas• 1 ~\'-"''~,..;.'> ·><.-.c'~ ·~~ <'&·~··' "2Q1 ' "'.)-5' Recessed 38 v 0.364 4.37 ~02 V /1 O' Recessed 5 -0.329 3.95 v2Q3 v ,,ro· Recessed 39 ,,... 0.380 4.56 ~04 V 15' Recessed 62 v 0.408 4.90 "'205 .V)O/Recessed 61 ,/ 0.333 3,99 "'206 v 15' Recessed 60 ~ 0.355 4.26 ;124 V 15' Recessed 40V 0.380 4.56 Transverse (Crown) slope (fVft) = 0 .038 Q~loot Qc•-*Y o..,,. •• (ft) (cfs) (cfs) llW"' 'R-. YJ!~'71 -,~~~:~~~ 0.66 9.85"' 0.93 "' 0.62 6.23 -2.03 .-- 0.68 6.57 .,.. 1,07 0.67 10,03 .... -1.72 0,63 6.26" -0 .70.,, 0.65 9.72<" -2 .59. 0.67 10,10 .... ·1 .64 " Straight Crown Flow (Solved to find actual depth of flow, yl : a• o .56 • (zin) • s"' • y"' ¢ y" {O / co.5s • (zin) • s"2n'11 n = Roughness Coefficient = z = Reciprocal of crown slope = S = StreetlGutter Slope (ft/ft) y = Depth of flow at inlet (ft ) Capacity of Inlets on grade : Oc • 0 .7 '(11(H1 • H2))' [H 1"2· H2 512] Oc =Flow capacity of inlet (cfs) H, "a+ y 0 .018 26 H2 = a = gutter depression (2" Standard; 4" Recessed ) y = Depth of flow in approach gutter (ft) 1 O yoor storm a. ...... a.....,_ Qbyp-cat.r (cfs) (cfs) from Jni.tt (cfs) :---~~ ,< ... ~ ~.;~:,-~~~ I ~~,,·~ 9.8&' 0.00 /0.93 ¥ 6.23 .... 0.00 .. 2.03 / 6,57 ./ 0.93 201 l '2 .0ff) 8,31 .... 2.03 202 1[;().,;lJj 5.56 ... 0.00 ... 0.00 ..... 7.12 v 0.00 211'1', 2es· "-0.00 8.45 ... ~ 0.00 0.00 --- ---- Q • ..,t-totl 010-Too• y,., (cfs) (cfs) (ft) (In) »\~,:" <.•· l};'...;,·i"' !-, -:> .. ;;x.,s;:-.' ~~ ..... -·"'- 9.85 / 10.78/ 0.407 4.89 6.23/ 8.26 ... 0.368 4.42 6.57"" .S .57" 0,461 5,64 10.03.' ,..{o.35 0.478 5.73 5,56 .. 5.56 0.372 4.47 7.12 .. 1.12....-0.475 5.69 8.45~~ -8.45 .... 0.425 5.10 100 year storm o ....... a. .. -QbrP•• o ....... (ft) (cfs) (cfs) (cfs) ,.~_-, .. ~:~1;;,_r;.; ·' .. ,. 0.70 10.50 4.03 10.50 0 .66 6,61 4.52 6.61 0 ,70 7.01 3.30 7.01 0.71 10.71 0.49 10.71 0.67 6.65 0.64 6.65 0 .69 10 .35 -0 .75 9.60 0.72 10 .78 0.61 10.78 Inlets In sumps. Weir Flow : L = Q I (3 • y"2) ¢ y • (Q I 3L)213 L = Length of Inlet open ing (ft) Q = Flow at inlet (els) y = total depth of flow on inlet (ft) max y for Inlet in sump = 7" = 0 .583' Co....,_ (cfs) from lnlrtt l ~ •i' '·--.~ 0.00 0.00 4.03 201 4.52 202 0.00 5.86 204, 205 0.00 -- - Qbyp.tol .. <le..,. .... 0100-11111 "' s L-... (cfs) (cfs) (cfs) (ft/ft) (ft) -~ ,,, ./!;, ..,...,. . .,, ....... 'lj ":.-~-.~~ 4.03 10 .50 14.53 0,0380 15 4.52 6.61 11 .14 0.0380 10 7.33 7.0 1 14 .33 0 .0190 10 5.02 10 .71 15.73 0.0190 15 0.64 6.65 7.49 0.0163 10 5.11 10 .35 15.46 0.0190 15 0.61 10.78 11 .39 0.0185 15 Castlegate Subdivision Pipe Calculations -Section 2 , Phase 1 In let outlet 10 year storm 1 oo year storm Pipe# Size Length Slope Invert Invert Elev Elev *ActualAow Deslgn Flow v,. 'lo Full Travel Time, t,,. *Actual Flow Design Flow v, .. %Full Travel Time, •t- (In) (ft) (%) (ft) (ft) (cfs) (cfs) (fps ) (sec) (min) (cfs) (cfs) (fps) (sec) (min) / 200 24 " 30.9 0 .60 314.81 .I 314.62 • 9 .85 >' / 15.91 5 .90 80 .0 ,.... 5 0 .09 10.50 16.96 5.88 86.4 y 5 0 .09 y 201 24"' 99 .8 1 .50 .. 313.65/ 312.1 5" 16.08 ,, 25.97 9 .33 82.8 / 11 0 .18 17.11 27 .63 9 .12 92.3 ,,, 11 0 .18 ,/ 202 24..--156.9 1 .5CV 311.48..-309.13 . 16 .08 25.97 9 .33 82 .8 _/ -17 0 .28 17.11 27 .63 9 .12 92.3 .,. .,%1 0 .29 "' 203 18 y 27.0 1 .2ov 309.95>' 309.6 3/ 6 .57 v 10 .61 6 .89 81 .3 ...-4 0 .07 7 .01 11.32 6 .82 88 .8 .. 4 0 .07 ,~04 27 " 94 .2 1 .30 308.8 51' 307.6:V ? 32.68 9.40 81 .7 _. 10 0 .17 34.83 9 .29 89.3 .V 10 0 .17 205 27V 57.2 1 .80 307.56J" 306.53>' 38.24 / (.11 '.'06__,,, 81.2 V 5 0 .09 41.48 10.77 92 .9 "' ~ 5 0 .09 ~v 206 36 " 139.4 " 0 .65" 305.78 >' 304.8 7"' 45.36 v 8 .00 74 .8 v 17 0 .29 51 .83 8 .02 85 .9 v , / 232/I 24 1 181 .3 '{ 1 .75 ._f 305.28"1 302.11 .IJ 8 .45 ./ 13.65 8 .81 49 .5 '1° 21 0 .34 10.78 17.41 9 .34 57 .4 vi 233./ 24 LI 130.5 cl-2 .00 rl 308.01 /1 305.40 /1 8 .45 v 13 .65 9 .26 I 47 .6 ,; 14 0 .23 10.78 17 .41 9 .8 3 55.o v l - *These values reflect the actual flow for the 18" & 24" pipes . T he design flow for th ese pipe sizes reflects a 25 % reduction in pipe area . (Refer to attached calculation for specific information.) 17 0.29 19 0 .32 13 0.22 C'-$?L.e: ~ ·~_:"("l t"V '2., p~ 1.. Is-; 7 / Acr---...- O~--- ;?V-/z_---O& ------- ---/ 7~?--01~-----------1 --~/f~ --_t2tf: ___ _ \ ' \ ( '" •,r •· .•. >\ ... ·-:. ---- ... .. ~. ·" - .. ---- \' \.-. ·. ---- \ ' . --------- --------- ---------------- ..-.+---- - - -----~---+:-+----- ;/O JI // -----------------~ o--,JI /'IJ --------------------------------------- 7/t? -}/ 17< -------------------~'----- ------------------ ------------;~-- -------------- %·~~"" ~'tL+-Lel /..t -//2 ~ //i.fl'-~ --=$W _=:: /J-/7_{ / ---of ~-------------7/0 iY'-17.! ~ -++ IrrtP{ ?/0 ~-------------- -L-/7~ .. .......... --~"< r-. . .. ' ~-~ CO LL lC.l STATIO!ll DEVELOPMENT PERMIT PERMIT NO. 500079 DP-CAS1LEGA TE SUB SEC 2 PH 1 FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: CAS1LEGA TE SECTION 2, PHASE 1 DATE OF ISSUE: January 05, 2001 OWNER: WALLA CE PIIlLLIPS GREENS PRAIRIE INVESTORS, LTD. 5010 AUGUSTA COLLEGE STATION, TEXAS 77845 SITE ADDRESS: 2270 GREENS PRAIRIE RD W DRAINAGE BASIN: SPRING CREEK VALID FOR 12 MONTHS CONTRACTOR: TYPE OF DEVELOPMENT: FULL DEVELOPMENT PERMIT SPECIAL CONDITIONS: All construction must be in compliance with the approved construction plans All trees must be barricaded, as shown on plans, prior to any construction. Any trees not barricaded will not count towards landscaping points. Barricades must be l' per caliper inch of the tree diameter. The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work. Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced before any operations of this permit can begin. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. I hereby grant this permit for development of an area outside the special flood hazard area. All development shall be in _ accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit · application for the above named project and all of the codes and ordinances of the City of College Station that apply. Date /')l~p9-0J ' oo -!:;o607q ~ l\-~d.-00 \ I',~ AM SUPPLEMENTAL DEVELOPMENT PERMIT INFORMATION Jplication is hereby made for the following development specific site/waterway alterations: S~Ai"~~aY\ ~ko stt v..L.--b.v-e Co111 <A·n&~c-Yl ACKNOWLEDGMENTS: I, --~-A._lio.u_~_--p-=-~--"lti,"""'4"'p"--~.;;;._.. ____ ., design engineer/~, hereby acknowledge or affirm that: The information and conclusions contained in the above plans and supporting documents comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and its associated Drainage Policy and Design Standards. As a condition of approval of this permit application, I agree to construct the improvements proposed in this application according to ~~~ Q. these documenlS and the req~nlS of Chap<er 13 of the College Station w ~ Property Owner(s) ' Contra CERTIFICATIONS: (for proposed alterations within designated flood hazard areas .) A. I, , certify that any nonresidential structure on or proposed to be on this site as part of this application is designr,ted to prevent damage to the structure or its contents as a result of flooding from the 100 year storm. Engineer Date L , certify that the finished floor elevation of the lowest floor, including any ..ement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended. Engineer Date C. L Jo ~ X . S c.b\A.-\ ~ , certify that the alterations or development covered by this permit shall not diminish the flood:cadYiflg capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent with requirements of the City of College Station City Code, Chapter 13 concerninL~nts of floodwaysandoffloodwayfring~ ~-:.._"'\t:.. OF !~!,.''• .fl ;~-<.. ~~.··*··········:'-<i'c51 •• r _ t I r-c.. c -o u r .. l ·· ...• •,. .< ~ * • • * ·~ Eng1neer Date ~··································i l JOSEPH P. SCHULTZ J D. L jo~9'v-i Y. Scbv....~\:L , do certify that the proposed alterations do not rai*~~:i;i{tfisegoo·;.~} flood ve elevation established in the atest Federal Insurance Administration Flood Hazard Study. ffO-<'···~G/sT""~~~·· ~.I J\ ,,~~ ....•.•• ;. .• ·· <3-t#' ---->-1r~-=~___,V_·__;=--'----=""""--[ ( ,__ '2. z._ -o ~ '\~~~tt~ Engineer Date Conditions or comments as part of approval : --------------------------~ .:cordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris rrom construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities . All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply. FINAL PLAT APPLICATION FNLPAPP.DOC Jn~/99 3 of3 . ' , I .. .If\ FOR OFFICE USE ONLY I '·7-p&z CASE NO.: 00-02) (o DATE SUBMITTED: l b:l ;);oo FINAL PLAT APPLICATION (check one) Minor _Amending /Final _Vacating _Replat 1be following items must be submitted by an established filing deadline date for P & Z Commission consideration . MINIMUM SUBMITTAL REQUIREMENTS: __.:::::_Filing Fee of $200.00. , ~Development Permit Application Fee of $100 .00 (if applicable). ~Infrastructure Inspection Fee of $300.00 (applicable if any public infrastructure is being constructed .). ~ Application completed in full . __:::::__Thirteen (13) folded copies of plat. (A signed mylar original must be submitted after staff review .) ---=::One (1) copy of the approved Preliminary Plat and/or one (1) Master Plan (if applicable). v" Paid tax certificates from City of College Station, Brazos County and College Station I.S.D . ._....... A copy of the attached checklist with_ all items checked off or a brief explanation as to why they are not. v Two (2)copies of public infrastructure plaps associated with ~s plat (if applicable). APPLICATION DATA -\ME OF SUBDMSION LOlzf~4 <S.J:Ji vi:~~ 1 Stoh'ru 2 1 7~ \ jECIFIED LOCATION OF PROPOSED SUBDMSION N'Pv-}k of bi#JA. ~ Prollv-~ ~ }2~ , vJRfik o£ ~o\'°W sra-h ~'1w%j 40. ., APPLICANT/PROJECT MANAGER'S INFORMATION (Primary Contact for the Project): Name Gx-.. g • .g...rys-Piro..-\<"~ ~\J'=£)>tov---s) Ltd-. -wo1\~ -Pk\li'?~ StreetAddress i::,o \O ~vsk CJ""~ City C()L~e StoJ,'l5YI State TA. Zip Code · 11co4-? E-Mail Address ----------- Phone Number q1't-la'12 ~ l'i)~Q FaxNumber 11Cf-let::to-/i}JOO / 2'5S-44-fo~ PROPER1Y OWNER'S INFORMATION: 7 Wta:>l:n'k Name ("Av=-~ \) v-o.lc ~ ,J:._v"1eJur7 1 L+J · Street Address 'Co\ o /v.°Jvs\:-o. G ~c.&. City Cc \Lea~e S5\a.b'Jr"Vl State rt Zip Code 11<t4? E-Mail Address ~~~~~~~~~~~- Phone Number 'l=r=l-la9 3-1 <03n Fax Number 9 7q -'19Q-I 4fX> ARCHITECT OR ENGINEER'S INFORMATION: Name l-t..X.c on -~ Sdu.J. -\-t. J J?. 'S . Street Address 1101 6v-°'-'~t2-Jl\0 ~ . City (p ~e S}-~ DYl State }L Zip Code .:ntA5 E-Mail Address :;:; ~cJ,,;,+;: @ ~ . Yle:J Phone Number °t1C\.-l/tO -11 t\ Fax Number W j 1 'l -__ 'O - _ ] FINAL PLAT APPLICATION FNLPAPP.DOC 3/2.5199 l ofJ . ,, TOTAL ACRES OF SUBDIVISION 15 . J \ TUMBER OF LOTS BY ZONING DISTRICT R-0-W ACREAGE '2.. SS TOTAL# OF LOTS 1-1 ---'---'--- 2..1 I Yl>b -\-\ /__ ----''-- AVERAGE ACREAGE OF EACH RESIDENTIAL LOT BY ZONING DISTRICT: D • ?;21 \?"QQ~1-t I I I __ FLOODPLAIN ACREAGE 0 ----- PARKLAND DEDICATION ACREAGE 4,3') OR FEE AMOUNT ____ _ A STATEMENT ADDRESSING ANY DIFFERENCES BE1WEEN THE FINAL PLAT AND APPROVED MASTER DEVELOPMENT PLAN AND/OR PRELIMINARY PLAT (IF APPLICABLE): ~o ..e._, REQUESTED VARIANCES TO SUBDIVISION REGULATIONS & REASON FOR SAME _______ _ Htev ..\-c TDD ·\\-1:-chA.o; ~J~ REQUESTEDOVERSIZEPARTICIPATION ~±..... i.Ja\.u~no a-AaVl~ oov--Jb "R· O·W o.£- ~o~o~ S\cw\& -x\;J~JL\o TOTAL LINEAR FOOTAGE OF PROPOSED : __ 1.."'--o""-A(e-=<--1 _ STREETS o SIDEWALKS --~--2~26' SANITARYSEWERLINES -~~~- I'\ /Jr{)' WATER LINES ~~,%~2-'-CHANNELS(}~~ _ __..?~l~...._'_STORMSEWERS __ \ .c\_o~o~'_DIKE LANES I PATHS NOTE: DIGITAL COPY OF PLAT (IF APPLICABLE) MUST BE SUBMITTED PRIOR TO FILING. The applicant has prepared this application and certifies that the facts stated herein and exhibits attached hereto are true, co"ect and complete. The undersigned hereby requests approval by the City of College Station of the above identified final plat. FINAL PLAT APPLICATION F'Nl .PA PP nnr '\ n ~ /QQ Date 2 of3 Castlegate Subdivision ·., , Section 2, Phase 1 College Station, Texas November 2000 Developer: Greens Prairie Investors, Ltd. By Greens Prairie Associates, LLC · 5010 Augusta College Station, Texas 77845 (979) 693-7830 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 690-7711 ~ l'di/qd~C}o() ~: 3.o \\: *' ~ CP~q CERTIFICATION I, Joseph P . Schultz , Licensed Professional Engineer No . 65889, State of Texas, certify that this report for the drainage design for the Castlegate Subdivision, Section 2, Phase 1 was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof. _,....,,,,,, --\E. OF '!' \\ ...c::~~ ········· ~J... , .. "'"' .. * .. ,..., " , •• •• 1,(\ t, '* .• '• v · ' "*: ·. *" ~············· ~ * ~ "-JOSEPH ··;»··st ........... ,,_ 'l_::.::: .. ••• ...... : ...... ~ULTZ ~ "I \,I .. ···········~ i~·~ esaag //:t:.! !.I '<' •• ~ ""' • ,;v #7 "t ~ ··lJ1srE?.~--::··~-v,,;f .,.s.s-1 •••••••••• 0".#' \~.._()NAL 'E..~-~~._.- TABLE OF CONTENTS DRAINAGE REPORT CASTLEGATE SUBDIVISION SECTION 2, PHASE 1 CERTIFICATION .................................................................................................................................................................. 1 TABLE OF CONTENTS ........................................................................................................................................................ 2 LIST OF TABLES .................................................................................................................................................................. 3 INTRODUCTION ................................................................................................................................................................... 4 GENERAL LOCATION AND DESCRIPTION .................................................................................................................. 4 FLOOD HAZARD INFORMATION .................................................................................................................................... 4 DEVELOPMENT DRAINAGE PATTERNS ....................................................................................................................... 4 DRAINAGE DESIGN CRITERIA ........................................................................................................................................ 5 STORM WATER RUNOFF DETERMINATION ............................................................................................................... 5 DETENTION FACILITY DESIGN ...................................................................................................................................... 7 STORM SEWER DESIGN .................................................................................................................................................... 7 CONCLUSIONS ..................................................................................................................................................................... 8 APPENDIX A .......................................................................................................................................................................... 9 Storm Sewer Inlet Design Calculations APPENDIX B ........................................................................................................................................................................ 11 Storm Sewer Pipe Design Calculations APPENDIX C ........................................................................................................................................................................ 25 Temporary Drainage Channel Design Calculations EXHIBIT A ............................................................................................................................................................................ 29 Of/site Infrastructure Plan for Castlegate Subdivision EXHIBIT B ............................................................................................................................................................................ 31 Post-Development Drainage Area Map 2 LIST OF TABLES TABLE 1 -Rainfall Intensity & Time of Concentration Calculations .............................................. 6 TABLE 2 -Post-Development Runoff Information ............................................................................ 6 3 DRAINAGE REPORT CASTLEGATE SUBDIVISION SECTION 2, PHASE 1 INTRODUCTION The purpose of this report is to provide the hydrological effects of the construction of the Castlegate Subdivision, Section 2, Phase 1 , and to verify that the proposed storm drainage system meets the requirements set forth by the City of College Station Drainage Policy and Design Standards. GENERAL LOCATION AND DESCRIPTION The project is located on a 162 acre tract located west of State Highway 6 along the north side of Greens Prairie Road in College Station , Texas. This report addresses Section 2, Phase 1 of this subdivision, which consists of 15.71 acres. The site is wooded with the vegetation primarily consisting of oak trees and yaupons. The existing ground elevations range from elevation 310 to elevation 330 . The general location of the project site is shown on the vicinity map in Exhibit B. FLOOD HAZARD INFORMATION The project site is located in the Spring Creek branch of the Lick Creek Drainage Basin. The site is locat ed in a Zone X Area according to the Flood Insurance Rate Map prepared by the Federal Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated areas dated July 2, 1992, panel number 48041C0205-C. Zone X Areas are determined to be outside of the 500-year floodplain . LJA Engineering & Surveying, Inc. submitted a Request for Conditional Letter of Map Revision (CLOMR) to FEMA to outline a proposed 100-year floodplain area. This CLOMR No . 00-06-844R was approved by FEMA on 9/8/2000. The proposed floodplain area does not affect Section 2, Phase 1. Phase 1 will continue to be in a Zone X Area . DEVELOPMENT DRAINAGE PATTERNS The storm water runoff from the site prior to development flows in one general direction. For Section 2, Phase 1, the acreage flows toward the west-northwest boundary of the tract and into existing drainage channels and Spring Creek and ultimately flows north to the proposed regional detention facility . Refer to the Offsite Infrastructure Plan in Exhibit A for the location of this proposed detention facility. 4 DRAINAGE DESIGN CRITERIA The design parameters for the storm sewer are as follows: • The Rational Method is utili zed to determine peak storm water runoff rates for the storm sewer design. • Design Storm Frequency Storm Sewer system • Runoff Coefficients Pre-development 10 and 100-year storm events Post-development (single family residential) c = 0 .30 c = 0 .55 • Rainfall Intensity values for Brazos County for a minimum time of concentration of 10 minutes can be found in Table 1. Where a longer time of concentration was necessary, it is noted in the respective table , and the intensities are calculated with the higher values where required. • Time of Concentration, tc -Due to the small sizes of the drainage areas, the calculated times of concentration , tc , are less than 10 minutes. Therefore, a minimum tc of 10 minutes is used in most cases to determine the rainfall intensity values. Where a longer time of concentration was necessary, it is noted and used accordingly. Refer to Table 1 for calculations. STORM WATER RUNOFF DETERMINATION The peak runoff values were determined in accordance with the criteria presented in the previous section for the 5, 10, 25, 50, and 100-year storm events . The runoff coefficients are based on the future development of this tract. The drainage areas for post-development are shown in Exhibit B. Post-development runoff conditions are summarized in Table 2. 5 TABLE 1 -Rainfall Intensity & Time of Concentration Calculations Rainfall Intensity Values (in/hr) Storm t = c Event 10 min Is 7.693 110 8.635 l2s 9.861 lso 11 .148 1100 11 .639 Brazos County: 5 }'.'.ear storm 10 }'.'.ear storm b = 76 b = 80 d = 8 .5 d = 8.5 e = 0 .785 e = 0 .76 3 I = b I (tc+d)e I = Rainfall Intensity (in/hr) tc = U(V*60) le= Time of concentration (min) L = Length (ft) V =Velocity (ft/sec) 25 }'.'.ear storm 50 }'.'.ear storm 100 }'.'.ear storm b = 89 b = 98 b = 96 d = 8.5 d = 8.5 d = 8.0 e = 0.754 e = 0 .745 e = 0.730 (Data taken from State Department of Hiqhwa}'.'.S and Public Transportation H}'.'.draulic Manual , page 2-16) TABLE 2-Post-Development Runoff Information A c tc Os Q 10 Q 2S Q so Area# (acres) (min) (cfs) (cfs) (cfs) (c fs) 5 1.74 0.55 1 0 7 .36 8.26 9 .44 1 0 .67 38 2.27 0 .55 1 0 9 .60 10.78 12 .31 1 3 .92 39 1 .61 0 .55 10 6 .81 7 .65 8. 7 3 9 .87 40 1. 7 8 0 .55 1 0 7 .53 8.45 9 .65 10 .91 41 2 .1 3 0 .55 10 9.01 1 0 .1 2 11 .5 5 1 3 .06 42 1 .38 0 .55 1 0 5 .84 6.55 7 .48 8 .46 43 1 .36 0 .55 10 5. 7 5 6.46 7 .38 8 .34 44 1 .69 0 .5 5 10 7 .1 5 8 .03 9 .1 7 1 0 .36 49 1 . 7 1 0.55 10 7 .24 8 .1 2 9 .27 1 0 .48 50 1 .06 0 .55 1 0 4 .49 5.03 5. 7 5 6.50 58 1 . 1 2 0 .55 1 0 4 .74 5 .32 6.07 6 .8 7 59 1 .32 0 .55 1 0 5 .59 6.27 7 .1 6 8 .0 9 60 1 .50 0 .55 1 0 6 .35 7 .1 2 8 .1 4 9 .20 61 1 . 1 7 0 .55 1 0 4 .95 5 .56 6 .35 7 .17 62 1 . 7 5 0 .55 1 0 7 .40 8 . 31 9 .49 10 .73 90 1 .32 0 .55 1 0 5 .59 6 .27 7 .1 6 8 .09 6 Q 100 (cfs) 1 1 . 1 4 14 .53 1 0 .31 11 .39 13 .6 4 8 .83 8. 71 1 0 .8 2 10 .95 6 . 79 7 .1 7 8.45 9.60 7 .49 11 .2 0 8 .45 DETENTION FACILITY DESIGN The detention facility handling the runoff from this site will be a regional facility designed by LJA Engineering & Surveying, Inc. Refer to the Offsite Infrastructure Plan in Exhibit A for the location of this proposed detention facility. The runoff from this project flows into existing drainages and then into Spring Creek. The detention facility is located adjacent to Spring Creek prior to Spring Creek entering the State Highway 6 right-of-way. STORM SEWER DESIGN The storm sewer piping for this project has been selected to be Reinforced Concrete Pipe (RCP) meeting the requirements of ASTM C-76, Class III pipe. The curb inlets and junction boxes will be cast-in-place concrete. Appendix A presents a summary of the storm sewer inlet design parameters and calculations. The inlets were designed based on a 10-year design storm. As per College Station guidelines, the capacities of inlets in sump were reduced by 10% to allow for clogging. Inlets were located to maintain a gutter flow depth of 5" or less , which will prevent the spread of water from reaching the crown of the road for the 10-year storm event. The runoff intercepted by the proposed storm sewer inlets was calculated using the following equations. The depth of flow in the gutter was determined by using the Straight Crown Flow equation. The flow intercepted by Inlets 201-206 & 224 was calculated by using the Capacity of Inlets On Grade equation . There are no inlets in sump for this phase of construction . The equation used for on-grade inlets and the resulting data are summarized in Appendix A. Appendix B presents a summary of the storm sewer pipe design parameters and calculations . All pipes are 18" in diameter or larger. For pipes with 18" and 24" diameters , the cross- sectional area is reduced by 25%, as per College Station requirements. A summary of how this was achieved is shown in Appendix B as well. The pipes for the storm sewer system were designed based on the 10-year storm event; however, all will also pass the 100-year storm event without any headwater. Based on the depth of flow in the street determined for the 100-year storm event, this runoff will be contained within the street right-of-way until it enters the storm sewer system. As required by College Station, the velocity of flow in the storm sewer pipe system is not lower than 2.5 feet per second, and it does not exceed 15 feet per second. As the data shows, even during low flow conditions, the velocity in the pipes will exceed 2.5 feet per second and prevent sediment build-up in the pipes. The maximum flow in the storm sewer pipe system will occur in Pipe No. 206. Appendix B contains a summary of the Manning pipe calculations as well as flow diagrams mapping the flows through the storm sewer system for the 10 and 100-year events. The maximum velocity for the pipe system in Section 2, Phase 1 will be 11.06 feet per second and will occur in Pipe 205. Pipes 206 & 233 will be stubbed out for this phase of construction. A temporary drainage channel will be constructed from the end of each of these stubbed out pipes. The locations of these channels are shown in Exhibit B . A temporary blanket easement has been provided to the City for the future development of adjacent areas and the construction of off-site drainage and utility facilities. The velocity in Channel No. 1 is 3.6 feet per second for the 10-year event, and 3.8 feet per second for the 100- year event. The velocity in Channel No . 2 is 3.1 feet per second for the 10-year event , and 3.3 fe et per second for the 100-year event. These velocities are within the requirements for a 7 seeded grass channel outlined on page 60 of the City of College Station Drainage Policy & Design Standards manual. Refer to Appendix C for details. CONCLUSIONS The construction of this project~ 1 significantly increase the storm water runoff from this site. The proposed storm sewer systen 3hould adequately control the runoff and release it into existing drainages . Also , the regional detention facility and the proposed ponds in the park area (addressed in Section 1, Phase 1) should adequately reduce the peak post-development runoff to less than the pre-development runoff for the design storm event. This will prevent any impact on the properties downstream of this project. 8 APPENDIX A Storm Sewer Inlet Design Calculations 9 Cas tlegate Subd iv ision Section 2 -Phase 1 Inlet Length Calculations No Inle ts in sump for this phase. Inlets On Grado Inl et # Length & Typo FlowfTom Area# Sec tion 21Phase 1 201 15" Recessed 38 202 1 o· Recessed 5 203 1 O' Recessed 39 20 4 15· Rece ssed 62 205 10· Reces sed 6 1 206 15' Recessed 60 224 15· Recessed 40 y,, (ft) (i n) 0.364 4.37 0.329 3.95 0.380 4.56 0.408 4.90 0.333 3.99 0.355 4.26 0.380 4.56 Transv erse (C rown) slope (fVft) = 0 .038 Q J)91'foot O cap.e1ty (ft) (cf s) 0.66 9.85 0.62 6.23 0.66 6.57 0.67 10 .03 0.63 6.26 0.65 9.72 0.67 10.10 Stra ight Crown Flow (S o lved to find actual dep th of flow , y l : Q bYPM• (cfs) 0.93 2.03 1.07 -1 .72 -0.70 -2 .59 -1.64 Q = 0.56 ' (zl n)' 5 112 ' y'" c:> y ={Q I [0 .56 ' (zl n) 'S112]}31' n = Roughness Coefficient = z = Reciprocal of crown slope = S = StreeVGutter Slope (fVft) y = Depth of flow at inlet (ft) Ca pacity o f Inl ets on grade : O c = 0.7 '[1 1(H 1 -H2)]' [H 1 512 • H,'12] Oc =Flow ca pacity of inlet (els) H 1 ~a + y 0 .0 18 26 H2 =a = gutter depression (2" Standa rd ; 4" Recessed) y = Depth of flow in approach gutter (ft) 10 y ear storm O eaptur•d O catryOY.r Q byp-toCal Q C::9Pl-tOCJ (cf s) (cfs) from Inlet # (cf s) (cf s) 9.85 0.00 0.93 9.85 6.23 0.00 2.03 6.23 6.57 0.93 201 2.00 6.57 8.31 2.03 202 0.31 10 .03 5.56 0.00 0.00 5.56 7.12 0.00 204 . 205 0.00 7.12 8.45 0.00 0.00 8.45 010-Tolal Y 100 (cf s) (ft) (In ) 10 .78 0.407 4.89 8.26 0.368 4.42 8.57 0.461 5.54 10 .35 0.478 5.73 5.56 0.372 4.47 7.12 0.475 5.69 8.45 0.42 5 5.10 100 yea r storm OJM,,oot O capaclty Q bYP•• O eal)lur•d (ft) (cfs ) (cfs) (cfs ) 0.70 10.50 4.03 10.50 0.66 6.61 4.52 6.61 0.70 7.01 3.30 7.01 0.71 10.71 0.49 10.71 0.67 6.65 0.84 6.65 0.69 10.35 -0 .75 9.60 0.72 10.78 0.61 10 .78 Inlets in sumps, Weir Fl ow : L = Q I (3 ' y 312) c:> y = (Q I 3L)213 L = Length of inlet opening (ft ) Q =Flow at in le t (cfs) y = total dep th of flow on in let (ft) m ax y for inl et in s um p = 7" = 0 .583' O cwryover (cf s) from In let # 0.00 0.00 4.03 201 4.52 202 0.00 5.86 204 . 205 0.00 O byp-1co1m1 O c1191-10U 0 100 .roea1 s LllCll••I (cf s) (cfs) (c fs ) (ft/ft) (ft) 4.03 10.50 14 .5 3 0.0380 ~ 4.52 6.61 11 .14 0.0380 ~ 7.33 7.0 1 14 .33 0.0190 10 5.02 10.71 15.73 0.0190 15 0.84 6.65 7.49 0.0 163 10 5.11 10.35 15.46 0.0190 15 0.61 10.78 11 .39 0.0185 15 APPENDIXB Storm Sewer Pipe Design Calculations 11 Castlegate Subdivision Pipe Calculations -Section 2 , Phase 1 Inlet Outlet 10 yea r s torm 100 y ear storm Pipe# Size Length Slope Invert Invert Elev Elev *Actual Flow Design Fl ow V10 % Full Tra ve l Time, tTto *Actual Flow Design Flow V 100 % Full (in) (ft) (%) (ft) (ft) (cfs) (cfs) (fps) (sec) (min) (cfs) (cfs) (fps) 200 24 30.9 0 .60 314.81 314 .62 9 .85 15 .91 5 .90 80 .0 5 0 .09 10 .50 16.96 5 .88 86.4 20 1 24 99.8 1 .50 313.65 312.15 16.08 25.97 9 .33 82.8 11 0 .18 17.11 27 .63 9 .12 92 .3 202 24 156.9 1 .50 311.48 309.13 16.08 25.97 9 .33 82 .8 17 0 .28 17.11 2 7 .63 9 .12 92 .3 203 18 27 .0 1 .20 309.95 309.63 6 .57 10 .61 6 .89 81 .3 4 O.D7 7 .01 11 .32 6 .82 88 .8 204 27 94 .2 1 .30 308.85 307.63 3 2 .68 9.40 81 .7 10 0 .17 34 .83 9 .29 89 .3 205 27 57 .2 1 .80 307.56 306.53 38.24 11 .06 81 .2 5 0 .09 41.48 10.77 92.9 206 36 139.4 0 .65 305.78 304 .87 45 .36 8 .00 74 .8 17 0 .29 51 .83 8 .02 85.9 232 24 181 .3 1 .75 305.28 302.11 8.45 13 .65 8 .81 49 .5 21 0 .34 10.78 17.41 9 .34 57.4 233 24 130.5 2 .00 308.01 305.40 8.45 13 .65 9 .26 47 .6 14 0 .23 10 .78 17.41 9 .83 55.0 *T hese values reflect the actual flow for the 18" & 24" pipes . The design flow for these pipe sizes reflects a 25% reduction in pipe area. (Refer to attached calculation for specific information .) Travel Time, lnoe (sec) (min) 5 0 .09 11 0 .18 17 0 .29 4 0 .07 10 0 .17 5 0 .09 17 0 .29 19 0 .32 13 0 .22 City of College Station requirement to Reduce Cross-Sectional Area of 18" & 24" Pipes by 25% Using Mannings Equation from page 48 of the College Station Drainage Policy & Design Standards Manual : Q = 1.49/n *A* R213 * S 112 Q = Flow Capacity (cfs) 18" Pipe: Pipe size (inches) = Wetted Perimeter W P, (ft)= Cross-Sectional Area A , (tt2) = Reduced Area AR, (ft2 ) = Hydraulic Radius R = NW P· (ft) = Reduced Hydr Radius RR = AR/WP • (ft) = Roughness Coefficient n = Friction Slope of Conduit S1o (ft/ft)= Example Calculation : Slope Fl ow Capacit y Reduce d Fl ow Ca pacity s Q 0 .005 6 .91 0.006 7 .57 0.007 8.18 24" Pipe: Pipe size (inches) = W etted Pe rimeter W P, (ft)= Cross-Sectional Area A, (tt2) = Reduced Area A R, (tt2) = Oredu ced 4 .28 4 .69 5 .06 Hydraulic Radius R = NW P' (ft) = Reduced Hyd r Radius RR = A R/W P• (ft) = Roughness Coefficient n = Friction Slope of Conduit S1, (ft/ft)= Example Calculation: Slope Flow Capaci ty Red uce d Fl ow Ca pa cit y s Q Oreduce d 0 .005 14 .89 9.22 0 .006 16 .31 10 .1 0 .007 17 .61 10 .9 Conclusion : 18 4 .71 1.766 1 .325 0 .375 0 .281 0 .014 0 .01 % Difference O re du ced/Q 0.619 0.619 0.619 24 6 .28 3.14 2.355 0.5 0 .375 0.014 0 .01 % Difference O redu ceiO 0.619 0.619 0.619 Multiply actual Q in 18" & 24" pipes by 1 .615 to reflect a 25% reduction in the cross-sectional area called for on page 47, paragraph 5 of the College Station Drainage Policy & Design Standards manu a l. Castlegate Subdivision Section 2, Phase 1 -Pipe Flow Diagram Inlet 201 I 9.85 i Pipe 200 1 9 .85 i Inlet 202 1 6.23 i Pipe201 I 16 .08 i June Box 200 i Pipe 202 1 16 .08 i Inlet 204 1 10 .03 i Pipe 204 1 32.68 i Inlet 205 1 5.56 i Pipe 205 1 38.24 i Inlet 206 1 7 .12 J, llPipe 206 1 45 .36 II (Into Phase 2) 010 (cfs) Inlet 203 6.57 i -4 ~ Pipe 203 6 .57 ... Inlet 224 1 8.45 i Pipe 233 1 8.45 i June Box 209 llPipe 232 1 8.45 II (Into Phase 2) Castlegate Subdivision Section 2, Phase 1 -Pipe Flow Diagram Inlet 201 I 10 .50 J, Pipe 200 1 10 .50 J, Inl et 202 1 6 .61 J, Pipe201 l 17 .11 J, Jun e Box 200 J, Pipe202 l 17 .11 J, Inlet 204 1 10 .71 J, Pipe 204 1 34 .83 J, Inlet 205 1 6.65 J, Pipe 205 1 41.48 J, In let 206 I 10 .35 J, llP ipe 206 1 51 .83 II (I nto Phase 2) 0 100 (cfs) Inlet 203 1 7 .01 J, Pipe 203 1 7 .01 Inlet 224 1 10 .78 J, Pipe 233 1 10 .78 J, Ju ne Box 209 J, llPipe 232 1 10 .78 (I nto Phase 2) Pipe 200 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 15.9100 cfs 0.0060 ft /ft 0 .0140 19.2062 in 3.1416 ft2 2.6951 ft2 53.1588 in 75.3982 in 5.9032 fps 7 .3007 in 80.0260 % 16 .2716 cfs 5.1794 fps Pipe 200 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 16.9600 cfs 0.0060 ft /ft 0.0140 20.7336 in 3.1416 ft2 2.8850 ft2 57.2616 in 75.3982 in 5.8786 fps 7.2552 in 86.3899 % 16 .2716 cfs 5.1794 fps Castlegate Subdivision, Section 2, Phase 1 College Station, Texas Pipe 2 01 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solv ing for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ........................... · Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24 .0000 in 25 .9700 cfs 0.0150 ft/ft 0.0140 19.8826 in 3 .1416 ft2 2.7828 ft2 54.8994 i n 75.3982 in 9 .3 325 fps 7.2991 in 82.8442 % 2 5 .727 6 cfs 8.1894 fps Pipe 201 -100 Year Storm Manning Pipe Ca l culator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hy draulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 24.0000 in 27.6300 cfs 0.0150 ft/ft 0. 0140 22.1468 in 3.1416 ft2 3.0298 ft2 61.8820 in 75.3982 in 9. 1193 fps 7.0505 in 92.2782 % 25.7276 cfs 8.18 9 4 fps Castlegate Subdivision, Section 2 , Phase 1 College Station, Texas Pipe 202 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perime t er ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 25.9700 cfs 0.0150 ft/ft 0. 0140 19 .8826 in 3.1416 ft2 2.7828 ft2 54 .8994 in 75 .3982 in 9.3325 fps 7.2991 in 82.8442 % 25.7276 cfs 8.1894 fps Pipe 202 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrat e ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 24.0000 in 27 .6300 cfs 0.0150 ft/ft 0. 0140 22.1468 in 3 .1416 ft2 3.0298 ft2 61.8820 in 75.3982 in 9 .1193 fps 7.0505 in 92.2782 % 25.7276 cfs 8.18 94 fps Castlegate Subdivision, Section 2, Phase 1 College Station, Texas Pipe 203 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 18.0000 in 10.6100 cfs 0 .0120 ft/ft 0. 0140 14.6397 in 1.7671 ft2 1. 5392 ft2 40.4645 in 56.5487 in 6.8932 fps 5.4775 in 81.3318 % 10.6850 cfs 6.0465 fps Pipe 203 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow veloci t y ............. . Circular Depth of Flow 18.0000 in 11.3 200 cfs 0.0120 ft/ft 0. 0140 15.9883 in 1.7671 ft2 1.6589 ft2 44.2775 in 56.5487 in 6.8238 fps 5.3951 in 88 .8241 % 10.6850 cfs 6 .0465 fps Castlegate Subdivision, Section 2 , Phase 1 College Station, Texas Pipe 204 -10 Year Storm Manning Pipe Calculator Given Inpu t Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloc ity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow veloci t y ............. . Circular Depth of Flow 27 .0000 in 32.6800 c fs 0. 0130 ft/ft 0.0140 22.0484 in 3.9761 ft2 3.4761 ft2 60.9254 in 84.8230 in 9.4012 fps 8.2160 in 81.6607 % 32 .7893 cfs 8 .2466 fps Pipe 204 -100 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Veloc ity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowra te ............. . Full flow velocity ............. . Circular Depth of Flow 27.0000 in 34.8300 cfs 0. 0130 ft/ft 0.0140 24.1144 in 3.9761 ft2 3.7479 ft2 66.8388 in 84.8230 in 9.2931 fps 8.0747 in 89.3124 % 32.7893 cfs 8.2466 fps Castlegate Subdivision , Section 2, Phase 1 College Station , Texas Pipe 205 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 27.0000 in 38.2400 cfs 0.0180 ft/ft 0. 0140 21.9150 in 3.9761 ft2 3.4567 ft2 60 .5825 in 84 .8230 in 11.0626 fps 8.2163 in 81.1667 % 38.5831 cfs 9.7038 fps Pipe 205 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Circular Depth of Flow 27.0000 in 41.4800 cfs 0.0180 ft/ft 0. 0140 25.0871 in 3.9761 ft2 3.8515 ft2 70.2743 in 84.8230 in 10.7697 fps 7.8922 in 92.9152 % 38 .5831 cfs 9.7038 fps Castlegate Subdivision, Section 2, Phase 1 College Station, Texas Pipe 206 -10 Year S t orm Manning Pipe Calculator Given Inpu t Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Res ult s: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Pe rime te r ............... . Perime te r ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve loci t y ............. . Circular Depth of Flow 36 .0 000 in 45 .3 600 cfs 0 .0065 ft/ft 0 .0140 26.9121 in 7.0686 ft2 5.6676 ft2 75 .1956 in 113. 097 3 in 8.0034 fps 10.8535 i n 74 .755 9 % 49.9330 cfs 7.0641 fps Pipe 206 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Compu ted Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Per imeter ............... . Perimete r ...................... . Veloci t y ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 36 .00 00 i n 51.8300 cfs 0 .0065 ft/ft 0. 014 0 30.9114 in 7.0686 ft2 6.4586 ft2 85.3456 in 113 .0973 i n 8.0249 fps 10.8974 in 85.8649 % 49.9330 cfs 7.0641 fps Castlegate Subdivision, Section 2, Phase 1 College Station , Texas Pipe 232 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 13.6500 cfs 0.0175 ft/ft 0. 0140 11.8754 in 3.1416 ft2 1.5500 ft2 37.4500 in 75.3982 in 8.8062 fps 5.9601 in 49.4810 % 27.7890 cfs 8.8455 fps Pipe 232 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow ve locity ............. . Circular Depth of Flow 24.0000 in 17.4100 cfs 0.0175 ft/ft 0.0140 13.7675 in 3.1416 ft2 1.8643 ft2 41.2470 in 75.3982 in 9.3386 fps 6.5086 in 57.3645 % 27.7890 cfs 8.8455 fps Castlegate Subdivision, Section 2, Phase 1 College Station, Texas Pipe 233 -10 Year Storm Manning Pipe Ca l culator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Dep t h .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 13. 6500 cfs 0.0200 ft/ft 0 . 0140 11. 4230 i n 3 .1416 ft2 1.4747 ft2 36.5446 in 7 5 .3 982 in 9.2563 f p s 5.8107 i n 47.5958 % 29 .7077 cfs 9.4563 fps Pipe 233 -100 Year Storm Manning Pipe Calculator Given Inpu t Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Res u lts : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydrau lic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24.0000 in 17.4100 cfs 0.0200 ft/ft 0. 0140 13.2046 in 3.1 416 ft2 1 .7712 ft2 40 .1124 in 75 .3982 in 9 .8293 fps 6.3586 in 55.0193 % 29.7077 cfs 9.4563 fps Castlegate Subdivision , Section 2, Phase 1 College Station, Texas APPENDIXC Temporary Drainage Channel Design Calculations 25 Castlegate Subdivision Temporary Dra i nage Channel Calculations -Section 2, Phase 1 Temporary Drainage Channel No. 1 A c t c 010 Area# (acres) (min) (cfs) 58 1.12 0 .55 10 5 .32 59 1.32 0 .55 10 6 .27 Fro m Pipe 206: 45.36 Total Fl ow to Temp Dra inage Chan ne l: 56.94 Temporary Drainage Channel No. 2 A c t c Area# (acres) (min) 4 1 2.13 0 .55 10 42 1.38 0 .55 10 Fro m Pip e 232 : Tota l Fl ow to Temp D rainage Channel : The Rational Method : Q=CIA Q = Flow (cfs ) A = Area (ac res ) C = Run off Coeff. I = Rai nfall Inte nsi ty (i n/hr) 010 (cfs) 10.11 6 .55 8 .45 25.11 0100 (cfs) 7 .17 8.45 5 1.83 67.45 0100 (cfs) 13.64 8.83 10.78 33.25 Temporary Drai n age Channe l No. 1 -1 0 Year Storm Ch a n ne l Calcul ato r Given Inpu t Data : Shape .......................... . S o l v i ng f o r .................... . Flowrate ....................... . Slope .......................... . Manni n g' s n .................... . Height ......................... . Bo ttom width ................... . Left slope ..................... . Righ t s l o p e .................... . Compu ted Resu l t s : Dep th .......................... . Veloc i ty ....................... . Full F l owra t e .................. . Flow area ...................... . Flow p erimeter ................. . Hy draulic rad i us ............... . To p width ...................... . Area ........................... . Perime t er ...................... . Percent full ................... . Trapezoidal De pth o f Fl ow 56.9400 c f s 0.0 040 ft /ft 0 .0300 42 . 0 000 in -k 0.0 000 in 0.5 0 00 ft/ft (V/H) 0 .500 0 f t /ft (V/H) 33.5718 i n 3 .6 375 fp s 103 .4703 cfs 1 5 .6537 f t 2 150 .1 378 i n 1 5 .0 138 i n 134 .2873 in 24 .5000 ft 2 187.8297 in 79 .9329 % - Temporary Drain a g e Ch anne l No . 1 -1 00 Yea r S t orm Chan nel Calcul ator Given Input Data: Shape .......................... . Solv ing for .................... . Fl o wrate ....................... . Slope .......................... . Manning ' s n .................... . Heigh t ......................... . Bot t o m wi d t h ................... . Le ft slope ..................... . Right s l ope .................... . Co mpu ted Res u lts: Dept h .......................... . Velocity ....................... . Full Flowra t e .................. . Flow area ...................... . F low perimeter ................. . Hy draulic rad i u s ............... . To p width ...................... . Area ..................... ·.· .... . P e r i meter ...................... . Perc ent full ................... . T r ap ezoidal De p t h of F low 67.4500 c f s 0.0 040 f t /f t 0 .0 300 42. 0000 i n ~ 0.0 000 i n 0 .50 00 f t /ft (V/H) 0.50 00 f t /f t (V/H) 35 . 7735 i n d>- 3 . 7948 fps 10 3.4703 cfs 17 .7742 ft 2 15 9 .9840 i n 15 .9984 i n 1 4 3.0941 in 2 4 .5000 ft2 187.82 9 7 in 85 .1 7 50 % Ca s t legate Subdiv ision, Section 2 , Phase 1 College Statio n, Tex as Temporary Drainage Channel No. 2 -10 Year Storm Channel Calculator Given Input Data : Shape .......................... . Solving for .................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Height ......................... . Bottom width ................... . Left slope ..................... . Right slope .................... . Computed Results: Depth .......................... . Velocity ....................... . Full Flowrate .................. . Flow area ...................... . Flow perimeter ................. . Hydraulic radius ............... . Top width ...................... . Area ........................... . Perimeter ...................... . Percent full ................... . Trapezoidal Depth of Flow 25.1100 cfs 0.0045 ft/ft 0.0300 36 .00 00 in 0 .0000 in 0.5000 ft/ft (V/H) 0.5000 ft/ft (V/H) 24.1571 in - 3.0981 fps 72.7557 cfs 8.1051 ft2 108.0338 in 10.8034 in 96.6284 in 18.0000 ft2 160 . 9969 in 67.1031 % Temporary Drainage Channel No. 2 -100 Year Storm Channel Calculator Given Input Data: Shape .......................... . Solv ing for .................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Height ......................... . Bottom width ................... . Trapezoidal Depth of Flow 33.2500 cfs 0 .0045 ft/ft 0.0300 36.0000 in 0.0000 in Left slope ..................... . Right slope .................... . 0.5000 ft/ft (V/H) 0 .5000 ft/ft (V/H) Computed Results: Depth .......................... . Velocity ....................... . Full Flowrate .................. . Flow area ...................... . Flow perimeter ................. . Hy draulic radius ............... . Top width ...................... . Area ........................... . 26.8395 in 3.3233 fps 72.7557 cfs 10.0050 ft2 120 .0298 in 12.0030 in 107.3579 in 18 .0000 ft2 Perimeter . . . . . . . . . . . . . . . . . . . . . . . 160.9969 in Percent full .................... 74.5541 % Castlegate Subdivis ion, Section 2, Phase 1 College Station, Texas - EXHIBIT A Offsite Infrastructure Plan for Castlegate Subdivision 29 EXHIBIT B Post-Development Drainage Area Map 3 1